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C. The frequency of nonresistant forms will increase in these populations.

Over the past several decades, natural selection has caused populations of Staphylococcus aureus (an infectious wound bacterium) to evolve resistance to most antibiotics. If antibiotic use were stopped, what would you predict would happen to these S. aureus populations?
A. They will go extinct without the antibiotic.
B. The populations will begin colonizing new environments.
C. The frequency of nonresistant forms will increase in these populations.
D. The frequency of resistant forms will definitely increase in these populations.

C. genus;species

Linnaus' taxonimic system specifies a unique name for each organism. The first part of the name is the organism's________, and the second part is its______.
A. species; genus
B. genus;phylum
C. genus;species
D. Phylum; Species

B. two

An atom has four electrons in its valence shell. How many double covalent bonds would you expect it to form in most circumstances?
A. one
B. two
C. three
D. four

A. after they have traveled 3 meters from the food source

Your colleague proposes to test the mechanism of ant navigation by placing a food source 7 m from the nest. She will then pick up the ants from the nest and move them 4 meters from the nest (3 m from the food source). Based on the previous data, when do you expect the ants to start searching for their nest on their return trip?
A. after they have traveled 3 meters from the food source
B. after they have traveled 4 meters from the food source
C. safter they have traveled 7 meters from the food source

C. when all of the electron orbitals in the valence shell are filled

When are stoms most stable?
A. whey they have fewest possible valence electrons
B. when they have the maximum number of unpaired electrons
C. when all of the electron orbitals in the valence shell are filled
D. when all electrons are unpaired

C. an isotope

If you change the number of neutrons in an atom, you create____.
A. a cation
B. an anion
C. an isotope
D. a different element

D. Animals and fungi are more closely related to each other than animals are to land plants.

On the tree of life, the branch leading to animals is closer to fungi than it is to the branch leading to land plants.
Which of the following statements is correct?
A. Animals and plants do not have a common ancestor.
B. Animals and land plants are more closely related to each other than either is to fungi.
C. Fungi and animals do not have a common ancestor.
D. Animals and fungi are more closely related to each other than animals are to land plants.

B. Cells would have appeared in both flasks.

Recall Pasteur's experiment on spontaneous generation. If he had just warmed the nutrient-rich broth, rather than boiled it,
what would have been the likely outcome of his experiment?
A) Cells would not have appeared in either flask.
B) Cells would have appeared in both flasks.
C) Cells would have appeared in the swan-neck, but not the straight-neck flask.
D) Cells would have appeared in the straight-neck, but not the swan-neck flask.

C. a nonpolar covalent bond

When the atoms involved in a covalent bond have the same electronegativity, what type of bond results?
A. an ionic bond
B. a hydrogen bond
C. a nonpolar covalent bond
D. a polar covalent bond

A. It has two more electrons than protons

If an atom has a charge of -2, which of the following must be true?
A. It has two more electrons than protons
B. It has two more protons than electrons
C. If has two more protons than neutrons
D. It has two more neutrons than electrons

C. ancestral groups that split into two or more descendant groups

What do nodes on phylogenetic tree represent?
A. environmental events that caused speciation
B. new kindgoms or domains
C. ancestral groups that split into two or more descendant groups
D. groups that got new names

C. all variables except leg length (and therefore stride length)

Recall the experiment on ant navigation. What parameters would have to be held constant for the test group of 75 ants in order to run a controlled experiment?
A. stride number
B. leg length
C. all variables except leg length (and therefore stride length)
D. stride number, leg length, and environmental temperature would all hae to be held constant

D. determining the number of tumors formed on a plant depending on how long it is exposed to Agrobacterium

Agrobacterium is a type of bacteria that infects plants and causes them to form tumors. You are asked to determine how long a plant must be exposed to the bacteria to become infected. Which of the following experiments will provide the best data for that question?
A) determining the survival rate of Agrobacterium to different concentrations of an antibiotic
B) determining the number of tumors formed on a plant depending on the concentration of Agrobacterium applied
C) determining the concentration of Agrobacterium in different soil environments
D) determining the number of tumors formed on a plant depending on how long it is exposed to Agrobacterium

A. miasma

The theory of ____ was the belief that sickness was caused from the inhalation of "bad air"
A. miasma
B. spontaneous generation
C. germ theory
D. evolution

A. exothermic

You've been asked to analyze a reaction that took place at 300 K. ∆H was -150 and ∆S was +0.4. Is the reaction endothermic or exothermic?
A. exothermic
B. endothermic
C. you cannot tell unless you know the potential energy of the reactants and products
D. you cannot tell unless you know the amount of disorder in the reactants and products

B. the reactants collide more often

Why do chemical reactions tend to speed up when the concentrations of the reactants is increased?
A. the reactants move faster
B. the reactants collide more often
C. the reactants have greater energy
D. all of the above apply

D. a reaction that is slightly exothermic and leads to a huge increase in entropy

Which reaction is most spontaneous?
A. a reaction that is slightly exothermic and leads to a slight increase in entropy
B. a reaction that is slightly endothermic and leads to a huge decrease in entropy
C. a reaction that is highly exothermic and leads to a huge decrease in entropy
D. a reaction that is slightly exothermic and leads to a huge increase in entropy

A. drive the equilibrium dynamics to the right and H2CO3 levels increase

Consider the following reaction at equilibrium: CO2 + H2O ↔ H2CO3. What would be the effect of adding additional CO2 and H20?
A. drive the equilibrium dynamics to the right and H2CO3 levels will increase
B. drive the equilibrium dynamics to the right and H2CO3 levels will decrease
C. drive the equilibrium dynamics to the left and H2CO3 levels will increase
D. drive the equilibrium dynamics to the left and H2CO3 levels will decrease
E. the reaction will be unchanged

A. hydrolysis reactions

Which of the following involves an increase in entropy?
A. hydrolysis reactions
B. condensation reactions
C. none of the above

A. CH3COOH

Consider the buffering example discussed in class. Acetic acid (CH3COOH) and acetate (CH3COO- ) form a buffer system. Which one of the buffer components would increase in concentration if we were to add a strong acid to the solution containing the buffer?
A. CH3COOH
B. CH3COO-
C. Both will increase
D. Both will decrease

B. a competitive inhibitor binds to the active site, whereas an allosteric inhibitor binds to a site other than the active site.

In what important way does a competitive inhibitor differ from an allosteric inhibitor?
A. A competitive inhibitor binds to a site other than the active site.
B. A competitive inhibitor binds to the active site, whereas an allosteric inhibitor binds to a site other than the active site.
C. An allosteric inhibitor is important in maintaining homeostasis, whereas a competitive inhibitor is not.
D. They are two different terms that mean the same thing.

B. CH3OO-

Consider the buffering example discussed in class. Acetic acid (CH3COOH) and acetate (CH3COO- ) form a buffer system. Which one of the buffer components would increase in concentration if we were to add a strong base to the solution containing the buffer?
A. CH3COOH
B. CH3COO-
C. Both will increase
D. Both will decrease

D. primary

You disrupt all hydrogen bonds in a protein. What level of structure will be preserved?
A. quaternary
B. tertiary
C. secondary
D. primary

D. all of the above

Why do chemical reactions tend to speed up when heat is applied to the reaction mixture?
A. the reactions move faster
B. The reactions have greater energy
C. The reactions collide more often
D. all of the above

C. specificity of enzymes binding to their substrate

The lock-and-key analogy for enzymes applies to the ____.
A. specificity of enzyme primary, secondary, and tertiary structure
B. specificity of enzyme tertiary subunits joining to form a quaternary structure
C. specificity of enzymes binding to their substrate
D. specificity of enzymes interacting with water
E. specificity of enzymes interacting with ions

B. It is probably an enzyme that works through allosteric regulation.

You have isolated a previously unstudied protein, identified its complete structure in detail, and determined that it catalyzes the breakdown of a large substrate. You notice it has two binding sites. One of these is large, apparently the bonding site for the large substrate; the other is small, possibly a binding site for a regulatory molecule. What do these findings tell you about the mechanism of this protein?
A. It is probably a structural protein that is involved in cell-to-cell adhesion.
B. It is probably an enzyme that works through allosteric regulation.
C. It is probably an enzyme that works through competitive inhibition.
D. It is probably a cell membrane transport protein-like an ion channel.
E. It is probably a structural protein found in cartilage or skeletal tissue.

A. primary structure of hemoglobin

Sickle-cell anemia results when valine replaces glutamate at position 6 of the B-globin subunit of hemoglobin. The sickling seen in red blood cells with the defective hemoglobin subunit affects the ______.
A. primary structure of hemoglobin
B. ability of oxygen and hydrogen to form hydrogen bonds
C. structure of the heme group found in hemoglobin
D. need for dietary iron

C. the components of the R-group

What aspects of amino acid structure vary among different amino acids?
A. the long carbon-hydrogen tails of the molecule
B. the presence of a central C carbon
C. the components of the R-group
D. the glycerol molecule that forms the backbond of the amino acid

C. hydrogen bond formed between the hydrogen of one water molecule and the oxygen of another water molecule

Water has a high specific heat because of the _____.
A. polar covalent bond formed between the oxygen and a hydrogen of a single water molecule
B. ionic bonds formed between the hydrogen of one water molecule and the oxygen of another water molecule
C. hydrogen bond formed between the hydrogen of one water molecule and the oxygen of another water molecule
D. covalent bond formed between the hydrogen of one water molecule and the oxygen of another water molecule

A. they reduce entropy

Why are polymerization reactions (such as the one used to link amino acids together to from proteins) considered endergonic?
A. They reduce entropy.
B. They release heat, making the reactant monomers move faster.
C. The condensation and hydrolysis reactions are equally spontaneous.
D. Polymers are energetically more stable and have lower potential energy than monomers do.

A. It acts as a base and gains a proton, giving it a positive charge.

At the pH found in cells (about 7.0), what happens to the amino group on an amino acid?
A. It acts as a base and gains a proton, giving it a positive charge.
B. It acts as an acid and loses a proton, giving it a negative charge.
C. It is reduced, and tends to act as an electron donor in redox reactions.
D. It remains neutral, like water, and does not have a charge.

D. Denatured (unfolded) proteins do not function normally.

Which of the following observations is the strongest argument in favor of the hypothesis that protein structure and function are correlated?
A. Proteins function best at certain temperatures.
B. Proteins have four distinct levels of structure and many functions.
C. Enzymes tend to be globular in shape.
D. Denatured (unfolded) proteins do not function normally.

C. hydrogen bonds between sections of the polypeptide backbone

What type of interaction is directly responsible for the formation of secondary structure in proteins?
A. peptide bonds between adjacent amino acids
B. peptide bonds between nonadjacent amino acids
C. hydrogen bonds between sections of the polypeptide backbone
D. hydrogen bonds between side chains of amino acids

D. It can form polar and nonpolar bonds

Which of the following is true of carbon?
A) It only forms polar molecules.
B) It can form a maximum of three covalent bonds with other elements.
C) It is highly electronegative.
D) It can form polar and nonpolar bonds.

C) It occurs every time a new species evolves from a preexisting species.

Which statement about spontaneous generation is false?
A) Pasteur demonstrated that it does not occur under normal laboratory conditions.
B) It apparently occurred at least once—when life on Earth began.
C) It occurs every time a new species evolves from a preexisting species.
D) It addresses the formation of living cells from previously nonliving material.

D) a reaction that is slightly exothermic and leads to a huge increase in entropy

Which reaction is most spontaneous?
A) a reaction that is slightly exothermic and leads to a slight increase in entropy
B) a reaction that is slightly endothermic and leads to a huge decrease in entropy
C) a reaction that is highly exothermic and leads to a huge decrease in entropy
D) a reaction that is slightly exothermic and leads to a huge increase in entropy

B) CH3COO-

Consider the buffering example discussed in class. Acetic acid (CH3COOH) and acetate (CH3COO- ) form a
buffer system. Which one of the buffer components would decrease in concentration if we were to add a strong acid to the solution containing the buffer?
A) CH3COOH
B) CH3COO-

D) 5' --> 3'

By convention, the sequence of bases in a nucleic acid is always written in which direction?
A) amino to carboxyl
B) carboxyl to amino
C) 3' → 5'
D) 5' → 3'

B) It has two more protons than electrons.

If an atom has a charge of +2, which of the following must be true?
A) It has two more electrons than protons.
B) It has two more protons than electrons.
C) It has two more protons than neutrons.
D) It has two more neutrons than electrons.

B) Cells would have appeared in both flasks.

Recall Pasteur's experiment on spontaneous generation. If he had just warmed the nutrient-rich broth, rather than boiled it, what would have been the likely outcome of his experiment?
A) Cells would not have appeared in either flask.
B) Cells would have appeared in both flasks.
C) Cells would have appeared in the swan-neck, but not the straight-neck flask.
D) Cells would have appeared in the straight-neck, but not the swan-neck flask.

D) The negative charges on the electrons are attracted by the positive charges on both nuclei.

What holds electrons in a covalent bond?
A) It is the fact that two electrons are paired in the same orbital.
B) The electron sharing that occurs makes the atoms involved smaller and more compact.
C) A decrease in potential energy, caused by electrical repulsion of the electrons in the bond, holds the electrons.
D) The negative charges on the electrons are attracted by the positive charges on both nuclei.

A) They reduce entropy.

Why are polymerization reactions endergonic?
A) They reduce entropy.
B) They release heat, making the reactant monomers move faster.
C) The condensation and hydrolysis reactions are equally spontaneous.
D) Polymers are energetically more stable and have lower potential energy than monomers do.

B) carbon and hydrogen

You isolate a molecule and determine it is nonpolar. Based on this property, the molecule is largely composed of the elements _____.
A) carbon and oxygen
B) carbon and hydrogen
C) carbon and nitrogen
D) nitrogen and hydrogen

B) secondary

Hairpins and stem-and-loop patterns make up what part of RNA's structure?
A) primary
B) secondary
C) tertiary
D) quaternary

A) +1

Nitrogen (N) normally forms only three covalent bonds because it has a valence of five. However, ammonium
has four covalent bonds, each to a different hydrogen (H) atom (H has a valence of one). Make a sketch of this molecule. Count the number of electrons in your sketch. Compare this number to the number of valence
electrons in one N and four H's. What do you predict to be the charge on this molecule?
A) +1 B) -1 C) +2 D) -2

B) DNA

A restriction enzyme cuts which particular molecule we discussed in class?
A) RNA
B) DNA
C) Proteins
D) Carbohydrates

D) RNA has 5' and 3' termini like DNA, but it also has amino and carboxyl termini like protein.

Which one of the following is not a way that RNA is seen as intermediate between DNA and proteins?
A) RNA contains genetic information like DNA, but is not as stable.
B) RNA can catalyze reactions, but not as well as can proteins.
C) RNA is composed of nucleotides, but forms tertiary and quaternary structures like a protein.
D) RNA has 5' and 3' termini like DNA, but it also has amino and carboxyl termini like protein.

C) One end has an unlinked 3' carbon; the other end has an unlinked 5' carbon.

Nucleic acids have a definite polarity, or directionality. Stated another way, one end of the molecule is different from the other end. How are these ends described?
A) One end has a hydroxyl group on the 2' carbon; the other end has a hydrogen atom on the 2' carbon.
B) One end contains a nitrogenous base; the other end lacks it.
C) One end has an unlinked 3' carbon; the other end has an unlinked 5' carbon.
D) One end has one phosphate group; the other end has two phosphate groups.

B) The catalyzed reaction will have a different ∆G.

Which of the following is not true when comparing an uncatalyzed reaction to the same reaction with a catalyst?
A) The catalyzed reaction will be faster. B) The catalyzed reaction will have a different ∆G.
C) The catalyzed reaction will have lower activation energy.
D) The catalyzed reaction will not consume any of the catalyst.

D) Land plants and algae have a common ancestor.

On the tree of life, branches that lead to several groups of green algae branch off from the one that leads to land plants. Which
one of the following statements is correct?
A) Green algae and land plants are not related.
B) Green algae are very closely related to the fungi.
C) Land plants appeared first in the fossil record.
D) Land plants and algae have a common ancestor.

D) The protein has quaternary structure.

An enzyme has a total of four active sites. When you denature the molecule and study its composition, you find that each active site occurs on a different polypeptide. Which of the following hypotheses does this observation support?
A) The enzyme is subject to allosteric regulation.
B) The enzyme requires a cofactor to function normally.
C) The protein's structure is affected by temperature and pH.
D) The protein has quaternary structure.

C) hydrogen bonds between sections of the polypeptide backbone

What type of interaction is directly responsible for the formation of protein secondary structure?
A) peptide bonds between adjacent amino acids
B) peptide bonds between nonadjacent amino acids
C) hydrogen bonds between sections of the polypeptide backbone
D) hydrogen bonds between side chains of amino acids

D) double antiparallel helical strands

Which of the following best describes DNA's secondary structure?
A) beta-pleated sheet
B) double parallel helical strands
C) turn-loop-turn
D) double antiparallel helical strands

D) any higher level folding of the protein will be incorrect.

If the primary structure of a protein is incorrect
A) the secondary structure will be correct.
B) the tertiary structure will be correct.
C) any quaternary structure will be correct.
D) any higher level folding of the protein will be incorrect.

B) It is probably an enzyme that works through allosteric regulation.

You have isolated a previously unstudied protein, identified its complete structure in detail, and determined that it catalyzes the breakdown of a large substrate. You notice it has two binding sites. One of these is large, apparently the bonding site for the large substrate; the other is small, possibly a binding site for a regulatory molecule. What do these findings tell you about the mechanism of this protein?
A) It is probably a structural protein that is involved in cell-to-cell adhesion.
B) It is probably an enzyme that works through allosteric regulation.
C) It is probably an enzyme that works through competitive inhibition.
D) It is probably a cell membrane transport protein-like an ion channel.
E) It is probably a structural protein found in cartilage or skeletal tissue.

D) their phosphate groups

What feature of mononucleotides provides the energy needed for polymerization when nucleic acids are formed?
A) their methyl groups
B) their sugar groups
C) their nitrogenous bases
D) their phosphate groups

B) At high substrate concentrations, the enzyme molecules present are working at maximal speed and are unable to further increase the rate of reaction.

Enzyme-catalyzed reactions increase in rate very rapidly at low substrate concentrations but plateau at higher substrate concentrations Why?
A) As substrate concentrations increase, the concentrations of inhibitors increase in order to maintain homeostasis.
B) At high substrate concentrations, the enzyme molecules present are working at maximal speed and are unable to further increase the rate of reaction.
C) Product concentrations are too high at high substrate concentrations.
D) An activator is necessary to maintain high reaction rates when substrate concentrations are high.

D) In DNA, the purine base adenine (A) always pairs with the pyrimidine base thymine (T).

Complementary base pairing explained Chargaff's findings—the fact that the number of cytosines in a DNA sample equals the number of guanines, and the number of thymines equals the number of adenines. Complementary base pairing is the formation of hydrogen bonds between antiparallel strands of the DNA molecule. Which statement regarding complementary base pairing is correct?
A) In DNA, the pairing of cytosine (C) with guanine (G) forms two hydrogen bonds.
B) The purine base cytosine (C) always pairs with the purine base guanine (G).
C) Purines always pair with other purines, and pyrimidines always pair with other pyrimidines.
D) In DNA, the purine base adenine (A) always pairs with the pyrimidine base thymine (T).

A) a chain of sugar and phosphate groups, linked through phosphodiester bonds

What forms the "backbone" of a nucleic acid?
A) a chain of sugar and phosphate groups, linked through phosphodiester bonds
B) purine and pyrimidine pairs, hydrogen-bonded to each other
C) a chain of amino and carboxyl groups, linked via peptide bonds
D) a double helix of antiparallel strands

B) phosphodiester

The type of bond that forms between a 3'-OH (hydroxyl) group of one nucleic acid and the 5'-P (phosphate) group of another nucleic acid is called a _________________ bond.
A) peptide
B) phosphodiester
C) ester
D) glycosidic

E) both B and D are correct.

What is gel electrophoresis used for?
A) to denature proteins for further analysis
B) to separate macromolecules such as DNA by size
C) to separate the two helices that make up the DNA double helix
D) to separate macromolecules such as DNA by charge
E) both B and D are correct.

D) competitive inhibition

HIV is the virus that causes AIDS. In the mid-1990s, researchers discovered an enzyme in HIV called protease. Once the enzyme's structure was known, researchers began looking for drugs that would fit into the active site and block it. If this strategy for stopping HIV infections were successful, it would be an example of what phenomenon?
A) vaccination
B) poisoning
C) allosteric regulation
D) competitive inhibition

A) hydrophobic

Consider the HIV enzyme called protease. The amino acid residues at the active site are highly hydrophobic. In designing a drug that would bind to the active site and jam it, researchers should use which type of molecule?
A) hydrophobic
B) polar
C) charged
D) acidic

B) Yes. Traits that help individuals produce more offspring in warmer environments will increase in frequency.

Environments all over the world are changing as a result of global warming. Could this influence natural selection?
A) No. The environment is always changing. Global warming is nothing new.
B) Yes. Traits that help individuals produce more offspring in warmer environments will increase in frequency.
C) No. The only change will be that species from hot environments will expand their ranges.
D) Yes. Mutations occur more frequently in hot environments.

A) a covalent bond forms between the sugar of one nucleotide and the phosphate of a second

When nucleotides polymerize to form a nucleic acid _____.
A) a covalent bond forms between the sugar of one nucleotide and the phosphate of a second
B) a hydrogen bond forms between the sugar of one nucleotide and the phosphate of a second
C) covalent bonds form between the bases of two nucleotides
D) hydrogen bonds form between the bases of two nucleotides

D) It has two mirror-image forms, which cannot be exactly superimposed on each other.

What does it mean to say that a molecule has an optical isomer?
A) It has secondary structure.
B) The isomers differ in the arrangement of carbons that make up the carbon skeleton.
C) The isomers differ in the arrangement of functional groups with respect to a C-C double bond.
D) It has two mirror-image forms, which cannot be exactly superimposed on each other.

d) both A and C are correct

Forensic science uses genetic fingerprinting techniques to identify individuals who may or may not have been present at crime scenes. These techniques identify unique patterns present in the DNA of each individual. What are these unique patterns based upon?
a) variable tandem nucleotide repeats present in the individual's DNA
b) variable tandem nucleotide repeats present in the individual's RNA
c) restriction digestion of a person's genetic material
d) both A and C are correct
e) both B and C are correct

B) If cofactors are missing, enzymes cannot function properly, and important reaction products will be absent from cells.

Several of the molecules called vitamins act as enzyme cofactors. Vitamin deficiencies cause disease. What is the most direct explanation for this?
A) Vitamins combine with nonprotein molecules to delay the onset of disease.
B) If cofactors are missing, enzymes cannot function properly, and important reaction products will be absent from cells.
C) Normal regulation cannot occur in the absence of cofactors. As a result, all enzymes will function all of the time.
D) Cofactors inhibit enzymes found in disease-causing bacteria and viruses. When cofactors are absent, these disease-causing agents multiply.

A) Substrates interact with R-groups at the enzyme's active site.

How does primary protein structure affect the function of protein enzymes?
A) Substrates interact with R-groups at the enzyme's active site.
B) Substrates interact with R-groups at the enzyme's external surface.
C) Substrates interact with hydrophobic R-groups at any region of the enzyme.
D) Substrates permanently bind to R-groups at the enzyme's active site.

D) more capsaicin

The "heat" in chili peppers is due to a molecule called capsaicin. Suppose you breed only the hottest chili peppers over many generations, predict the characteristics of the resulting individuals.
A) larger fruits
B) smaller fruits
C) less capsaicin
D) more capsaicin

a. Enzyme B-functions best at a pH of 3 and a temperature of 90°C

From the list below, choose the most likely enzyme to be present in a bacterium found in a hot water vent in an acidic current.
a. Enzyme B-functions best at a pH of 3 and a temperature of 90°C
b. Enzyme A-functions best at a pH of 10 and a temperature of 90°C
c. Enzyme D-functions best at a pH of 7 and a temperature of 50°C
d. Enzyme C-functions best at a pH of 10 and a temperature of 30°C

d. They help maintain homeostasis with respect to pH.

What is the significance of buffers in biological systems?
a. They are not present and are therefore insignificant in biological systems.
b. They are usually involved in chemical reactions that result in energy production.
c. They help maintain a constant temperature in biological systems.
d. They help maintain homeostasis with respect to pH.

C) stating both a specific hypothesis about why the car won't start and a prediction of the hypothesis.

A friend of yours calls to say that his car would not start this morning. He asks for your help. You say that you think the battery must be dead, and that if so, then jump-starting the car from a good battery will solve the problem. In doing so, you are
A) only stating a hypothesis for why the car won't start.
B) searching for observations that might inspire a hypothesis for why the car won't start.
C) stating both a specific hypothesis about why the car won't start and a prediction of the hypothesis.
D) performing an experimental test of a hypothesis for why the car won't start.

B. endothermic

You've been asked to analyze a reaction that took place at 300 K. ∆H was +150 and ∆S was +0.4. Is the reaction endothermic or exothermic?
A. exothermic
B. endothermic
C. You cannot tell unless you know the potential energy of the reactants and products.
D. You cannot tell unless you know the amount of disorder in the reactants and products.
E. The reaction is at equilibrium

D) because it is unlikely that all reaction products are required all of the time

In cells, the activity of enzymes is often regulated by other molecules. Why is this necessary?
A) because all enzymes require some help from another molecule to function correctly
B) because other molecules are necessary to prevent enzymes from denaturing
C) because each enzyme has multiple functions
D) because it is unlikely that all reaction products are required all of the time

b. triose

A carbohydrate with the molecular formula C3H6O3 would most accurately be classified as what type of sugar?
a. hexose
b. triose
c. pentose
d. aldose e. ketose

a. structural polysaccharide

The extensive hydrogen bonding found among parallel glucose polymers of cellulose enables it to function in plants as a(n) _____.
a. structural polysaccharide
b. transport molecule
c. energy source
d. storage polysaccharide

b. Glycoproteins are important in cell-cell recognition.

What is an important function of glycoproteins in animal cells from an immune system standpoint?
a. Glycoproteins serve as shuttles bringing molecules into a cell.
b. Glycoproteins are important in cell-cell recognition.
c. Glycoproteins are important in the maintenance of membrane electrochemical potential.
d. Glycoproteins contribute to the hydrophobicity of the cell membrane.

c. glucose; ATP

When cells need energy, reactions break down _____ in the cell and capture the released energy by synthesizing _____.
a. phosphate; carbohydrates
b. carbon dioxide; glucose
c. glucose; ATP
d. carbon dioxide; oxygen
e. ATP; glucose
f. ATP; fats

C) peptidoglycan

If you were going to develop a new antibiotic, you would probably need to become an expert on which of these carbohydrates?
A) glycogen
B) chitin
C) peptidoglycan
D) cellulose
E) starch

B) Sunlight energy can be used by plants to reduce the carbon atoms in carbon dioxide to from carbohydrates.

Why do plants require sunlight?
A) Sunlight helps plants break down their food products so they can extract the energy stored in them.
B) Sunlight energy can be used by plants to reduce the carbon atoms in carbon dioxide to from carbohydrates.
C) Sunlight oxidizes carbon dioxide and water to form glucose.
D) Sunlight can be used directly by plants to perform a number of physiological processes.

B) Animals have the enzymes to degrade α-1,4-glycosidic bonds, but not β-1,4-glycosidic bonds..

Both starch and cellulose are glucose polymers. Why can animals easily degrade starch, but not cellulose?
A) Animals have enzymes to degrade α-1,4-glycosidic bonds, but not α-1,6-glycosidic bonds.
B) Animals have the enzymes to degrade α-1,4-glycosidic bonds, but not β-1,4-glycosidic bonds..
C) Cellulose is much more rigid than starches because of the extensive peptide and covalent bonding between adjacent glucose polymers in cellulose. Animals are unable to destroy these hydrogen bonds.
D) The glucose of cellulose has amino functional groups that participate in the formation of glycosidic bonds and animals do not have the enzymes necessary to degrade these bonds.

B) Evolutionarily, producing an enzyme to break down a sugar that will never be encountered is wasteful.

Dairy cattle were unknown in Thai culture until recently, and 97% percent of Thai people are lactose intolerant as adults. Which explanation for such widespread lactose intolerance is most likely correct?
A) Allergies are becoming more common in humans as more chemicals are being encountered during longer lifetimes.
B) Evolutionarily, producing an enzyme to break down a sugar that will never be encountered is wasteful.
C) The ability to digest sugar in milk is determined by environment, and most humans are not exposed to milk as a food source beyond childhood years.
D) There is no good explanation for this situation in humans.

C) Individual strands are joined by amino acid cross bridges connected by peptide bonds - a type of covalent bond.

Peptidoglycan forms sheets that stiffen the cell walls of bacteria. How is the formation of sheets possible?
A) The polysaccharides in peptidoglycan are highly branched and form a network.
B) The glycosidic linkages between monosaccharides in peptidoglycan are extraordinarily strong.
C) Individual strands are joined by amino acid cross bridges connected by peptide bonds - a type of covalent bond.
D) The polysaccharides in peptidoglycan form helical structures, as in cellulose.

b. transient galactosemia

Drinking a gallon of milk in under an hour, or "Joeying" the milk causes a condition we discussed in class called___________.
a. lactose intolerance
b. transient galactosemia
c. transient lactosemia
d. galactose intolerance

C)α-1,6-glycosidic linkage

Which of the following linkages would you expect to find at a branch point in glycogen or amylopectin, a common metabolically utilized sugar?
A) α-1,4-glycosidic linkage
B) β-1,4-glycosidic linkage
C)α-1,6-glycosidic linkage
D) β-1,6-glycosidic linkage

b. Alexander Fleming

_____________________ is given credit for the discovery of the first antibiotic.
a. Robert Koch
b. Alexander Fleming
c. Robert Hooke
d. Louis Pasteur
e. Roberto Bartel

b. move two potassium ions and three sodium ions while consuming an ATP for each cycle

Sodium-potassium pumps:
a. move three potassium ions and two sodium ions while producing an ATP for each cycle.
b. move two potassium ions and three sodium ions while consuming an ATP for each cycle.
c. produce ATP for cells while making the outside of cell membranes negatively charged.
d. use ATP molecules to move protons to the inner side of cell membranes.

d. a transport protein that facilitates diffusion of a large molecule across cell membranes

GLUT-1 is an example of what? Points:5 (Extra Credit) Question GLUT-1 is an example of what?
a. a membrane-bound pump that moves large molecules against a gradient by using ATP
b. a protein that is toxic to cells by opening channels in membranes
c. a recognition protein that identifies cells as belonging to the body
d. a transport protein that facilitates diffusion of a large molecule across cell membranes

e. depending upon the permeability of the molecule to the membrane, both c and d are possible answers.

Which of the following means of transport would most likely be used for moving a large-sized molecule (like a monosaccharide or an amino acid) from a high concentration on the outside of a cell to a low concentration on the inside of a cell?
a. active transport through a "pump" protein
b. facilitated diffusion through an ion channel protein
c. facilitated diffusion through a transporter protein
d. passive transport
e. depending upon the permeability of the molecule to the membrane, both c and d are possible answers.
f. depending upon the permeability of the molecule to the membrane, both a and b are possible answers.

a. gated

Some channel proteins change their conformations (alter their folding) in response to either allosteric binding by a ligand or the development of a electrochemical gradient along the membrane. These channels can be characterized as ____________ channels.
a. gated
b. opened
c. closed
d. fenced

a. symporter

In the co-transport example discussed in class, H+ ions are pumped out of the cell against their concentration gradient at the expense of ATP hydrolysis. H+ molecules are then brought back into the cell along their concentration gradient in a channel protein along with sucrose molecules moving against its concentration. This co-transport system in which both molecules enter the cell is an example of a(n) __________.
a. symporter
b. antiporter
c. proton pump
d. none of the above

d. polar heads and nonpolar tails; the polar heads interact with water

Lipids that form membranes have what kind of structure?
a. completely nonpolar, because they are lipids
b. completely polar, which allows them to dissolve in water
c. polar heads and nonpolar tails; the nonpolar tails interact with water
d. polar heads and nonpolar tails; the polar heads interact with water

d. spanning the cell membrane, with parts of the protein visible from both the inside and the outside of the cell

Where would you most likely find an integral membrane protein?
a. on the inside surface of the cell membrane
b. on the outside surface of the cell membrane
c. floating freely in the cytoplasm
d. spanning the cell membrane, with parts of the protein visible from both the inside and the outside of the cell

d. Ions do not diffuse across lipid bilayers.

In an experiment involving planar bilayers, a solution of table salt (sodium and chloride ions in water) is added on the left side of the membrane while pure water is added on the right side. After 30 minutes the researchers test for the presence of ions on each side of the membrane. The right side tests negative for ions. What can you conclude?
a. The experiment failed.
b. The water somehow blocked the movement of ions across the bilayer.
c. The left side would also probably test negatively for the presence of ions.
d. Ions do not diffuse across lipid bilayers.

c. Because cholesterol is amphipathic, it fits in between the phospholipids and blocks diffusion through the membrane by increasing hydrophobic interactions.

Which of the following is the best explanation for why cholesterol decreases the permeability of biological membranes?
a. Cholesterol binds to the outside surface of a membrane, thus blocking the movement of solutes.
b. Because cholesterol is amphipathic, it fits in between the phospholipids and blocks diffusion through the membrane by increasing hydrophilic interactions.
c. Because cholesterol is amphipathic, it fits in between the phospholipids and blocks diffusion through the membrane by increasing hydrophobic interactions.
d. Cholesterol has four rings in its structure that can sequester (trap) solutes.

c. Permeability to glucose will decrease.

You have a planar bilayer with equal amounts of saturated and unsaturated phospholipids. After testing the permeability of this membrane to glucose, you increase the proportion of saturated phospholipids in the bilayer. What will happen to the membrane's permeability to glucose?
a. You can't predict the outcome. You simply have to make the measurement.
b. Permeability to glucose will increase.
c. Permeability to glucose will decrease.
d. Permeability to glucose will stay the same.

a. The cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the rbc.

What will happen to a red blood cell (rbc), which has an internal ion concentration of about 0.9 percent, if it is placed into a beaker of pure water (no ions present)?
a. The cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the rbc.
b. The cell would shrink because the water in the beaker is hypertonic relative to the cytoplasm of the rbc.
c. The cell would shrink because the water in the beaker is hypotonic relative to the cytoplasm of the rbc.
d. The cell would swell because the water in the beaker is hypertonic relative to the cytoplasm of the rbc.

a. osmosis

The movement of water from a region of low solute concentration to a region of high solute concentration occurs by the process of _____.
a. osmosis
b. diffusion
c. active transport
d. facilitated diffusion

b. fluid-mosaic; embedded within the membrane and on the surfaces of the membrane.

What is the name of the currently accepted model of membrane structure, and where does it place membrane proteins?
a. fluid-mosaic; on the surfaces of the membrane only
b. fluid-mosaic; embedded within the membrane and on the surfaces of the membrane.
c. sandwich; on the outside and inside surfaces of the membrane only
d. sandwich; embedded within the membrane and on the surfaces of the membrane

c. The cell would shrink because the water in the beaker is hypertonic relative to the cytoplasm of the rbc.

What will happen to a red blood cell (rbc), which has an internal ion concentration of about 0.9 percent, if it is placed into a beaker of water that has an ion concentration of 9.0 percent?
a. The cell would swell because the water in the beaker is hypertonic relative to the cytoplasm of the rbc.
b. The cell would shrink because the water in the beaker is hypotonic relative to the cytoplasm of the rbc.
c. The cell would shrink because the water in the beaker is hypertonic relative to the cytoplasm of the rbc.
d. The cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the rbc.

c. It forms a channel in the membrane.

Which of the following best describes how gramicidin functions?
a. It acts by active transport.
b. It causes membranes to fuse with one another.
c. It forms a channel in the membrane.
d. It removes electrical charges from solutes.

c. The hydrophobic amino acids would be oriented toward the outside of the protein and come into contact with the hydrocarbon tails of the phospholipid bilayer, whereas the hydrophilic proteins would be more concentrated in the protein interior.

Proteins are amphipathic molecules that contain nonpolar (hydrophobic) amino acids and polar (hydrophilic) amino acids. Where would you expect to find the hydrophobic and hydrophilic amino acid residues of a protein that spans a cell membrane?
a. Membrane proteins are oriented such that their amino acid residues do not come into contact with the membrane interior
b. The hydrophobic regions of the protein would clump together in the protein interior through hydrophobic interactions, whereas the hydrophilic regions would be oriented outward, coming into contact with the phospholipid bilayer
c. The hydrophobic amino acids would be oriented toward the outside of the protein and come into contact with the hydrocarbon tails of the phospholipid bilayer, whereas the hydrophilic proteins would be more concentrated in the protein interior.
d. Proteins are found only on the membrane surface. The hydrophilic regions would be attached to the phosphate groups of membrane phospholipids through ionic bonds, whereas the hydrophobic groups would be oriented toward the extracellular fluid.

a. on the surface of hemoglobin

Valine, a nonpolar amino acid, shows up in the wrong place in the hemoglobin of sickle-cell anemia, causing the disease. This is due to a genetic mutation. The result of this mutation is that hemoglobin molecules—which transport oxygen in red blood cells—stick together, causing the red blood cells to become distorted, but without having any significant effect on oxygen binding. Based on what you know about protein structure and the polarity of amino acids, predict where the mutated valine would most likely be found.
a. on the surface of hemoglobin
b. in the deep interior of hemoglobin
c. in the oxygen binding site of hemoglobin
d. along a nonpolar region of a β-pleated sheet

a. Vegetable oil has more double bonds than animal fats.

Which of the following is the best explanation for why vegetable oil is a liquid at room temperature while animal fats are solid?
a. Vegetable oil has more double bonds than animal fats.
b. Vegetable oil has fewer double bonds than animal fats.
c. Animal fats have no amphipathic character.
d. Vegetable oil has longer fatty-acid tails than animal fats have.

f. both a and d

Why don't bacterial cells burst in a hypotonic solution?
a. The bacteria will gain some water to their surroundings, but continually expel additional water through specialized aquaporins to maintain cell volume
b. The bacteria will lose some water to their surroundings, but continually take on additional water through specialized aquaporins to maintain cell volume
c. The bacteria that survive in hypotonic habitats have adapted to survive with very low internal solute concentrations.
d. Bacteria have a cell wall
e. both b and d
f. both a and d

e. both A and C

What would happen if the NA+/K+ ATPase we discussed in class hydrolyzed ATP resulting in a bound phosphate allosterically associated with the protein and then developed a mutation in which the ability to remove the phosphate group was "lost", i.e. the transporter would be unable to remove the phosphate group bound to it?
a. The Na+/K+ ATPase would be locked in a confirmation with its K+ binding sites exposed and would be unable to return to its native confirmation.
b. The Na+/K+ ATPase would be locked in a confirmation with its Na+ binding sites exposed and would be unable to return to its native confirmation.
c. Although the Na+ ions would be released, the K+ ions would remain bound to their binding sites without the release of the phosphate group.
d. Although the K+ ions would be released, the Na+ ions would remain bound to their binding sites without the release of the phosphate group
e. both A and C
f. both B and D

c. Once concentrations of glucose were equal on both sides of the cell membrane, transport of glucose would stop.

What would happen to the transport of glucose by the GLUT-1 protein if the hexokinase enzyme (the enzyme that phosphorylates glucose upon its entry into the cell) developed a mutation that resulted in the loss of the ability to phosphorylate glucose?
a. Glucose concentration would increase on the outside of the cell in the aqueous environment.
b. Glucose concentration would increase in the cytoplasm of the cell.
c. Once concentrations of glucose were equal on both sides of the cell membrane, transport of glucose would stop.
d. None of the answers above are correct

A) signal recognition particle

ccording to the signal hypothesis, as the ribosome begins to translate a new protein, the first couple of amino acids translated by the ribosome will end up being bound by the _______________.
A) signal recognition particle
B) signal recognition particle receptor
C) signal peptidase
D) chaperones

a. a decrease in pH mediated by H+ flux through membrane vacuolar ATPases on the lysosome

. The hydrolytic enzymes (hydrolyases) present in the lysosome only become active upon phagosome-lysosome fusion. What is the signal that leads to their activation?
a. a decrease in pH mediated by H+ flux through membrane vacuolar ATPases on the lysosome
b. an increase in pH mediated by H+ flux through membrane vacuolar ATPases on the lysosome
c. an increase in Ca2+ concentration due to the opening of voltage regulated channels
d. the components in the phagosome determine the activation of the hydrolyases

B) mitochondria; bacteria

Margulis's theory of endosymbiosis proposes that ____________ evolved from ___________.
A) chloroplast; fungus
B) mitochondria; bacteria
C) chloroplast; virus
D) mitochondria; virus
E) nucleus; algae

B. mitochondria

You have a distant cousin, age 4, who is always tired and fatigued and is not able to play games and sports like other healthy children. He most likely has an enzyme deficiency or defect associated with which intracellular organelle?
A. lysosomes
B. mitochondria
C. golgi apparatus
D. ribosomes

B. Actin and myosin are among the cytoskeletal proteins important in cell movement.

Which of the following cytoskeletal proteins are important in changing cell shape or location (any type of cell movement)?
A. Actin is the only cytoskeletal proteins important in cell movement.
B. Actin and myosin are among the cytoskeletal proteins important in cell movement.
C. Actin, microtubules, and intermediate filaments are equally important in cell movement.
D. Intermediate filaments are the only cytoskeletal proteins important in cell movement.

A. lysosomes

A large carbohydrate is tagged with a fluorescent marker and placed in the extracellular environment surrounding a eukaryotic cell. The cell ingests the carbohydrate via endocytosis. Upon viewing the cells with a microscope, which of the following cellular substructures is likely to be fluorescently labeled?
A. lysosomes
B. mitochondria
C. nucleus
D. ribosomes

A. abnormal cell shape

Spherocytosis is a defect associated with a defective cytoskeletal protein in red blood cells. What do you suspect is one consequence of defective cytoskeletal proteins in red blood cells?
A. abnormal cell shape
B. insufficient energy supply in the cell
C. a lack of oxygen-transporting proteins in the cell
D. adhering of blood cells to blood-vessel walls, causing the formation of plaque

E. both A and B are possible

Which of the following statements would best describe a cell that has an extensive area of smooth endoplasmic reticulum?
A. It can synthesize steroids.
B. It synthesizes large quantities of lipids.
C. It synthesizes digestive enzymes.
D. It is able to both import and export protein molecules.
E. both A and B are possible
F. both A and C are possible

B. Eukaryotic cells tend to have much more extensive inner membrane systems and larger numbers of intracellular organelles than do prokaryotes.

Which of the following statements represents a major difference between prokaryotic cells and eukaryotic cells?
A. Prokaryotes have cells while eukaryotes do not.
B. Eukaryotic cells tend to have much more extensive inner membrane systems and larger numbers of intracellular organelles than do prokaryotes.
C. Prokaryotes are not able to carry out aerobic respiration, a process that requires a complex inner-membrane system.
D. Prokaryotes are generally larger in size than eukaryotes

g. both A and D

What would you predict about a integral membrane protein found on the plasma (cell) membrane?
a. It must be translated by the ribosomes associated with the rough ER
b. It must be translated by "free" ribosomes in the cytoplasm
c. In the vesicle leaving the golgi apparatus, the protein must be soluble in the vesicular cytoplasm
d. In the vesicle leaving the golgi apparatus, the protein must be inserted in the vesicular membrane
e. both A and C
f. both B and D
g. both A and D

A) cytokinesis

The formation of a cleavage furrow in animal cells results from interactions between actin and myosin proteins. This process occurs at the end of mitosis and is referred to as _________________.
A) cytokinesis
B) cytoplasmic streaming
C) pseudopodia formation

a. autophagy

Lysosomal fusion and degradation of damaged organelles is a process called __________________.
a. autophagy
b. receptor mediated endocytosis
c. phagocytosis
d. pinocytosis

A) They do not have a polar or charged region.

. Cooking oil and gasoline (a hydrocarbon) are not amphipathic molecules. Why?
A) They do not have a polar or charged region.
B) They do not have a hydrophobic region.
C) They are highly reduced molecules.
D) They spontaneously form micelles or liposomes in solution.

c. The axoneme will elongate or grow in length as it will be unable to bend or "whip"

. Suppose that the plasma membrane around a eukaryotic flagellum is opened to reveal the axoneme inside. The radial spokes connecting the peripheral microtubule doublets to the central pair are then broken by chemical treatment and ATP is added. What is the expected observation?
a. There will be normal bending of the flagellum.
b. There will be no movement, because the plasma membrane is not present.
c. The axoneme will elongate or grow in length as it will be unable to bend or "whip"
d. There will be no movement, because the ability to use ATP is lost.

e. Glucose 6-phosphate concentrations would increase in the cytoplasm

What would happen to the transport of glucose by the GLUT-1 protein if the hexokinase enzyme (the enzyme that phosphorylates glucose upon its entry into the cell) developed a mutation that resulted in an overactive enzyme that was able to phosphorylate glucose twice as fast as the normal enzyme?
a. Glucose concentration would increase on the outside of the cell in the aqueous environment.
b. Glucose concentration would decrease in the cytoplasm of the cell.
c. Once concentrations of glucose were equal on both sides of the cell membrane, transport of glucose
would stop.
d. The mutation would have no effect on the ability of GLUT-1 to transport glucose
e. Glucose 6-phosphate concentrations would increase in the cytoplasm

D) one with short and unsaturated tails

Which of the following phospholipid membranes would be most permeable to glycerol?
A) one with long and saturated fatty-acid tails
B) one with long and unsaturated tails
C) one with short and saturated tails
D) one with short and unsaturated tails

B) whenever a solute needs to be moved from low concentration to high concentration through a phospholipid bilayer membrane

Under what circumstances does membrane transport always require energy?
A) whenever molecules are moved that are too large to pass through the phospholipid bilayer membrane
B) whenever a solute needs to be moved from low concentration to high concentration through a phospholipid bilayer membrane
C) whenever a solute is charged, such as an ion, and is moved through a phospholipid bilayer membrane
D) whenever a molecule is polar and is moved through a phospholipid bilayer membrane

C) It forms a channel in the membrane.

Gramicidin is an antibiotic that increases the permeability of bacterial cell walls to inorganic ions. What is the most likely mode of action of gramicidin?
A) It acts by active transport.
B) It causes membranes to fuse with one another.
C) It forms a channel in the membrane.
D) It removes electrical charges from solutes.

E) both A and C

In the nucleoplasmin experiment discussed in class, protease treatment was used to separate the protein into "core" and "tail" regions. After radiolabeling of the core and tail fragments, it was observed that core fragments remained in the cytoplasm while tail fragments were transported to the nucleus. Why?
A)core fragments lacked a nuclear localization signal
B)intact protein structure was required for nuclear localization
C)tail fragments contained a nuclear localization signal
D)both A and B
E) both A and C

a. the ring configuration

The predominant form of glucose dissolved in an aqueous solution is _____.
a. the ring configuration
b. as a ketose
c. the linear form
d. as a disaccharide

c. Animals have the enzymes to degrade α-1,4-glycosidic bonds, but not β-1,4-glycosidic bonds.

Both starch and cellulose are glucose polymers. Why can animals easily degrade starch, but not cellulose?
a. Animals have enzymes to degrade α-1,4-glycosidic bonds, but not α-1,6-glycosidic bonds.
b. Cellulose is much more rigid than starches because of the extensive hydrogen bonding between adjacent glucose polymers in cellulose. Animals are unable to destroy these hydrogen bonds.
c. Animals have the enzymes to degrade α-1,4-glycosidic bonds, but not β-1,4-glycosidic bonds.
d. The glucose of cellulose has amino functional groups that participate in the formation of glycosidic bonds. animals do not have the enzymes necessary to degrade these bonds.

A) have receptors that recognize and bind the hormone molecule.

Hormones are chemical substances produced in one organ that are released into the bloodstream and affect the function of a target organ. For the target organ to respond to a particular hormone, it must ________.
A) have receptors that recognize and bind the hormone molecule.
B) be from the same cell type as the organ that produced the hormone.
C) be experiencing a disruption in homeostasis.
D) have the same genetic makeup.

b. structural polysaccharide

The extensive hydrogen bonding found among parallel glucose polymers of cellulose enables it to function in plants as a(n) _____.
a. storage polysaccharide
b. structural polysaccharide
c. transport molecule
d. energy source

d. glucose; ATP

When cells need energy, reactions break down _____ in the cell and capture the released energy by synthesizing _____.
a. phosphate; carbohydrates
b. carbon dioxide; glucose
c. carbon dioxide; oxygen
d. glucose; ATP

c. on the exterior surface of the cell membrane

Glycoproteins are important in cell-cell recognition. Where are the carbohydrate portions of these molecules normally found?
a. on the inside surface of the cell membrane
b. embedded in the interior of the cell membrane
c. on the exterior surface of the cell membrane
d. in the nucleus of the cells

C) active transport through a "pump" protein

Which of the following means of transport would most likely be used for moving a medium-sized molecule (like a monosaccharide or an amino acid) from a low concentration on the outside of a cell to a high concentration on the inside of a cell?
A) facilitated diffusion through an ion channel protein B) facilitated diffusion through a transporter protein
C) active transport through a "pump" protein
D) passive transport

D) amplified

The fact that a single signal-receptor complex results in the activation of several second messenger molecules enables the cell signal to be ________.
A) terminated
B) reflected
C) altered
D) amplified

B) the arrangement of microtubules within the axoneme

To what does the 9 + 2 arrangement of microtubules, typical of cilia and eukaryotic flagella, refer?
A) the arrangement of dynein arms with respect to each microtubule
B) the arrangement of microtubules within the axoneme
C) the length of the structures
D) the relationship between the basal body and the axoneme

D) a small, nonpolar molecule like oxygen (O2)

Which of the following crosses lipid bilayers the fastest?
A) a sodium ion
B) a small, polar molecule like water
C) a large, polar molecule like glucose
D) a small, nonpolar molecule like oxygen (O2)

A) abnormal cell shape

Spherocytosis is a defect associated with a defective cytoskeletal protein in red blood cells. What do you suspect is one consequence of defective cytoskeletal proteins in red blood cells?
A) abnormal cell shape
B) insufficient energy supply in the cell
C) a lack of oxygen-transporting proteins in the cell
D) adhering of blood cells to blood-vessel walls, causing the formation of plaque

D) Proteins that are destined to be secreted outside the cell follow a specific pathway that culminates with secretory vesicle fusion with the plasma membrane releasing the protein into the extracellular space.

In the pulse-chase experiment discussed in class, researchers applied a short pulse of radioactively labeled leucine, followed by a long chase of unlabeled leucine, to cells that secrete digestive enzymes. The bulk of the radioactive label was initially found in the rough ER, then in the Golgi apparatus, followed by secretory vesicles that emptied into a duct outside the cell. These results BEST support which of the following hypotheses?
A) Materials exit the cell via endocytosis and enter via exocytosis
B) Microtubules and other elements of the cellular cytoskeleton are dynamic
C) Cargo is transported through the endomembrane system according to specific lipid "tags"
D) Proteins that are destined to be secreted outside the cell follow a specific pathway that culminates with secretory vesicle fusion with the plasma membrane releasing the protein into the extracellular space.

A) Their ring structures differ in the location of a hydroxyl group.

How do the α and β forms of glucose differ?
A) Their ring structures differ in the location of a hydroxyl group.
B) Their linear structures differ in the location of a hydroxyl group.
C) The β form can be involved in 1,4 and 1,6 glycosidic linkages; the α form can participate only in 1,4 linkages.
D) The oxygen atom inside the ring is located in a different position.

C) epinephrine

When you are startled, and have an autonomic response preparing you to flee from danger, which of the following is released into your bloodstream that leads to a variety of different effects in a variety of different tissues? (Hint: What causes the "fight or flight" response?)
A) testosterone
B) glucose
C) epinephrine
D) estrogen

A) selective toxicity

The concept of ______________________ explains why antibiotics like penicillin and antimicrobial substances like lysozyme kill or inhibit the growth of bacteria without a similar effect upon the infected host.
A) selective toxicity
B) antibiotic selectivity
C) self versus non-self
D) enzyme specificity
E) the immune response

C) The cell would shrink because the water in the beaker is hypertonic relative to the cytoplasm of the rbc.

What will happen to a red blood cell (rbc), which has an internal ion concentration of about 0.9 percent, if it is placed into a beaker of 9.0% salt water? (Hint think about cytoplasm concentration relative to outside)
A) The cell would swell because the water in the beaker is hypertonic relative to the cytoplasm of the rbc.
B) The cell would shrink because the water in the beaker is hypotonic relative to the cytoplasm of the rbc.
C) The cell would shrink because the water in the beaker is hypertonic relative to the cytoplasm of the rbc.
D) The cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the rbc.

A) chloroplast; cyanobacteria

Applying Margulis's theory of endosymbiosis, it has been shown that ____________ evolved from ___________ in plant cells.
A) chloroplast; cyanobacteria
B) mitochondria; bacteria
C) chloroplast; virus
D) mitochondria; virus
E) cyanobacteria; chloroplast

A) one with carbon and hydrogen atoms only

Which of the following molecules would you expect to have the most free energy per gram?
A) one with carbon and hydrogen atoms only
B) one with carbon, hydrogen, and oxygen atoms only
C) one with a variety of atoms that are found in cells D) one with hydrogen and oxygen atoms only

B) water and small ions can readily pass from one cardiac muscle cell to the next, "sharing nutrients".

Intercalated disks are cell-cell junctions found between cardiac muscle cells. A feature of intercalated disks is a large number of gap junctions. This means ________.
A) an extension of smooth endoplasmic reticulum goes through the gap junction, making it continuous from one cardiac muscle cell to the next.
B) water and small ions can readily pass from one cardiac muscle cell to the next, "sharing nutrients".
C) the plasma membrane encompasses multiple cardiac muscle cells.
D) lysosomes from one cardiac muscle cell can be transported into an adjacent cell through the gap junction.

C) It actively exports protein molecules.

What is the most likely role of a cell that contains an extensive rough ER?
A) It plays a role in storage.
B) It synthesizes large quantities of lipids.
C) It actively exports protein molecules.
D) It plays a role in immune function.

C) be transported through the nuclear pore complex.

Steroid hormones bind to receptors inside the cell and alter their conformation. The hormone-receptor complex is then transported into the nucleus, where it can directly affect gene expression. To get from the location where the receptor binds the hormone to its site of action, the receptor-hormone complex must ________.
A) undergo modification in the Golgi apparatus.
B) become water soluble by binding to a carrier molecule.
C) be transported through the nuclear pore complex.
D) enter the smooth endoplasmic reticulum.

B) Muscles would be unable to relax.

Acetylcholine is a neurotransmitter that binds to receptors on skeletal muscle cells. This binding brings about a series of events that result in contraction of skeletal muscle. Venom from black widow spiders causes an explosive release of acetylcholine. What would that do to its victims?
A) Muscles would be unable to contract.
B) Muscles would be unable to relax.
C) Cell receptors would no longer be able to bind regulatory hormones.
D) G-protein receptors would all be inactivated.

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