145 terms

BIO 111 Test Two Review

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A
Changing a single amino acid in a protein consisting of 433 amino acids would

A. always alter the primary structure of the protein and sometimes alter its tertiary structure or function.

B. always alter the primary structure of the protein but never alter its tertiary structure or function.

C. always alter the primary and tertiary structure of the protein but never alter its function.

D. sometimes alter the primary and tertiary structure of the protein but always alter its function.
Nucleic acids
If cells are grown in a medium containing radioactive 32P, which of these molecules will be radioactively labeled?
44
How many peptide bonds are present in a polypeptide that contains 45 amino acids?
35%
If a DNA sample were composed of 15% adenine, what would be the percentage of guanine?
15%
If a DNA sample were composed of 15% adenine, what would be the percentage of thymine?
Phospholipids
Which of the following large biological molecules will self-assemble into a bilayer when mixed with water?
C
Lactase is an enzyme composed of a single polypeptide that hydrolyzes the disaccharide lactose to produce monosaccharides. The optimal pH for lactase activity is 6. Transfer of lactase to pH 5 results in a substantial decrease in enzyme activity, likely due to the disruption of

A. only the primary structure of the enzyme.

B. the primary and secondary structure of the enzyme.

C. the secondary and tertiary structure of the enzyme.

D. the secondary, tertiary, and quaternary structure of the enzyme.
Teritary
A structure is achieved when a protein folds into a compact, three-dimensional shape stabilized by interactions between side-chain R groups of amino acids.
Primary
A structure is the sequence of amino acids in a protein.
Secondary
A structure describes the alpha-helices and beta-sheets that are formed by hydrogen bonding between backbone atoms located near each other in the polypeptide chain.
Quaternary
A structure is the result of two or more protein subunits assembling to form a larger, biologically active protein complex.
Cholesterol
Which of the following molecules lacks amino acids?

antibodies
insulin
spider silk
cholesterol
hemoglobin
D
There are 20 different amino acids. What makes one amino acid different from another?

A. different asymmetric carbons

B. different side chains (R groups) attached to the carboxyl carbon

C. different side chains (R groups) attached to the amino groups

D. different side chains (R groups) attached to an α carbon
C
Which bonds are created during the formation of the primary structure of a protein?

A. hydrogen bonds
B. phosphodiester bonds
C. peptide bonds
D. disulfide bonds
A
Which type of interaction stabilizes the α helix and the β pleated sheet structures of proteins?

A.hydrogen bonds
B.peptide bonds
C.hydrophobic interactions
D.ionic bonds
Secondary
The α helix and β pleated sheet are examples of which level of protein structure?

primary
secondary
tertiary
quaternary
primary, secondary, tertiary, and quaternary
E
Normal hemoglobin is a tetramer, consisting of two molecules of β-globin and two molecules of α-globin. In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits

A. altered primary structure.
B. altered secondary structure.
C. altered tertiary structure.
D. altered quaternary structure.
E. altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered.
E
The flow of genetic information in a cell goes from __________.

A. DNA to ribosomes to RNA
B. protein to RNA to DNA
C. DNA to lipid to protein
D. DNA to RNA to glucose
E. DNA to RNA to protein
C
A nucleotide is composed of

A. a nitrogenous base and a pentose sugar.

B. a nitrogenous base and a phosphate group.

C. a nitrogenous base, a phosphate group, and a pentose sugar.

D. a nitrogenous base, a phosphate group, a pentose sugar, and an amino acid.
cytosine, thymine, uracil
What are three examples of pyrimidines?
guanine and adenine
What are two examples of purines?
A
The difference between the sugar in DNA and the sugar in RNA is that the sugar in DNA

A. contains one less oxygen atom than the sugar in RNA.

B. is a six-carbon sugar and the sugar in RNA is a five-carbon sugar.

C. is a five-carbon sugar and the sugar in RNA is a six-carbon sugar.

D. is in the α configuration and the sugar in RNA is in the β configuration.
D
The sequence 5'-GAACUT-3' may be found in which of the following?

A. DNA only

B. RNA only

C. either DNA or RNA

D. neither DNA or RNA
C
The sequence 5'- GAACGA'3' may be found in which of the following?

A. DNA only
B. RNA only
C. either DNA or RNA
D. neither DNA nor RNA
C
If one strand of a DNA molecule has the sequence of bases 5'-ATTGCA-3', the other complementary strand would have the sequence

A. 3'-UAACGU-5'.
B. 5'-TGCAAT-3'.
C. 5-'TAACGT-3'.
D. 5'-UAACGU-3'.
E
Which of the following choices correctly matches a tool and its proper application?


A. transmission electron microscopy (TEM) to study the movement of organelles within a living cell

B. scanning electron microscopy (SEM) to study the detailed movements of living cells

C. light microscopy to study the internal structure of cilia

D. transmission electron
microscopy (TEM) to study the surfaces of preserved cells

E. cell fractionation to study the function of specific organelles
B
When biologists wish to study the internal ultrastructure of cells, they can achieve the finest resolution by using a

A. phase-contrast light microscope.

B. transmission electronic microscope.

C. scanning electron microscope.

D. confocal fluorescence microscope.
C
One advantage of light microscopy over transmission electron microscopy is that

A. light microscopy provides for higher magnification than transmission electron microscopy.

B. specimen preparation for light microcopy does not produce artifacts.

C. light microscopy allows one to view dynamic processes in living cells.

D. light microscopy provides for higher resolving power than transmission electron microscopy.
C
When subcellular components from disrupted cells are separated using centrifugation, the primary factor that determines whether a specific cellular component remains in the liquid solution or ends up in the pellet is

A. how hydrophobic the component is.

B. the relative solubility of the component.

C. the relative size and weight of the component.

D. the carbohydrate composition of the component.
C
What technique would be most appropriate to use to observe the movements of condensed chromosomes during cell division?

A. transmission electron microscopy
B. scanning electron microscopy
C. standard light microscopy
D. super-resolution microscopy
E
A biologist wants to examine the surfaces of different types of cells in kidney tubules of small mammals. The cells in question can be distinguished by external shape, size, and 3-D characteristics. Which of the following would be the optimum method for her study?

A. light microscopy using stained sections of kidney tissue

B. transmission electron microscopy

C. light microscopy of living unstained material

D. cell fractionation

E. scanning electron microscopy
Fimbriae
_________ are surface appendages that allow a bacterium to stick to a surface.
C
What is the function of a bacterium's capsule?

A. protein synthesis
B. propulsion
C. protection
D. DNA storage
E. adhesion
Nucleoid Region
The DNA-containing region of this bacterial cell is the _____.
Nuleoid Region
Where is a bacterial cell's DNA found? (Prokaryotic Cell)
Ribosomes
In a bacterium, where are proteins synthesized?
cell wall
What name is given to the rigid structure, found outside the plasma membrane, that surrounds and supports the bacterial cell?

capsule
pili
cell wall
flagella
nucleoid region
plasma memebrane
The _____ is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell.
plasma membrane
The structure that regulates the passage of material into and out of this bacterial cell is indicated by the _____.
D
Which of the following clues would tell you if a cell is prokaryotic or eukaryotic?


A. the presence or absence of a rigid cell wall

B. whether or not the cell carries out cellular metabolism

C. the presence or absence of ribosomes

D. whether or not the cell is partitioned by internal membranes

E. whether or not the cell contains DNA
ER (endoplasmic reticulum)
This may be found in eukaryotic cells, but not in bacteria?
Mitochondria
Nearly found in all eukaryotic cells?
D
Beginning within the nucleus, the first step leading to the synthesis of a polypeptide is _____.

A. linking of nucleotides to form a polypeptide

B. removal of introns from RNA and the stitching together of exons

C. translation of a DNA nucleotide sequence into a sequence of amino acids

D. transferring of information from DNA to messenger RNA

E. translation of an RNA nucleotide sequence into a sequence of amino acids
Proteins
Large numbers of ribosomes are present in cells that specialize in producing which molecules?
Lysosome
Which organelle plays a role in intracellular digestion?
Rough ER
Which structure is the site of the synthesis of proteins destined for export from the cell?
Smooth ER
The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells?
Smooth Endoplasmic Reticulum
Which type of organelle or structure is primarily involved in the synthesis of oils, phospholipids, and steroids?
A
Which of the following statements correctly describes a function of the Golgi apparatus?

A. protein modification and sorting

B. synthesis of cytoplasmic proteins

C. assembly of ribosomal subunits

D. detoxification of toxins
Lysosomes
Hydrolytic enzymes must be segregated and packaged to prevent general destruction of cellular components.

In animal cells, what organelles contains these hydrolytic enzymes?
Lysosome
Tay-Sachs disease is a human genetic abnormality that results in cells accumulating very large, complex, undigested lipids. Which cellular organelle must be defective in this condition?
nuclear envelope
One of the key innovations in the evolution of eukaryotes from a prokaryotic ancestor is the endomembrane system. Which eukaryotic organelles or features might have evolved as a part of, or as an elaboration of, the endomembrane system?
Vacuole (Central)
Which organelle often takes up much of the volume of a plant cell?
E
Which of the following correctly describes the pathway taken by a protein destined for secretion from an animal cell?

A. plasma membrane → transport vesicle → Golgi → transport vesicle → rough ER

B. rough ER → transport vesicle → Golgi → transport vesicle → lysosome → plasma membrane

C. Golgi → rough ER → transport vesicle → plasma membrane

D. rough ER → transport vesicle → Golgi → transport vesicle → plasma membrane

E. rough ER → transport vesicle → lysosome → transport vesicle → plasma membrane
C
Comparison of samples from the liver of an alcoholic with samples from the liver of a non-drinker when examined by transmission electron microscopy would likely reveal that

A. the ultrastructure of the two livers is very similar.

B. the liver of the non-drinker has expansive rough ER compared to the alcoholic's liver.

C. the liver of the alcoholic has expansive smooth ER compared to the non-drinker's liver.

D. the liver of the alcoholic has substantially more lysosomes than the non-drinker's liver.
B
Mitochondria are found in __________.


A. animal cells and prokaryotic cells but not plant cells
B. plant and animal cells
C. plant cells only
D. animal cells only
E. all cells
A
Which of the following are common traits of chloroplasts and mitochondria?


A. Both have their own DNA.
B. Both are surrounded by a single membrane.
C. Both are found in plant and animal cells.
D. Both reproduce by meiosis.
E. Proteins for both are synthesized on ribosomes in the rough ER.
B
A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from

A. an archaeal or eukaryotic organism.
B. any eukaryotic organism.
C. a bacterium.
D. an animal, but not a plant.
Plastids
What organelles is found exclusively in plant cells?
Mitochondrion
Which plant cell organelle contains its own DNA and ribosomes?
Peroxisome
Which animal cell organelle contains enzymes that transfer hydrogen from various substrates to oxygen?
Chloroplasts
Thylakoids, DNA, and ribosomes are all components found in
B
In an animal cell, DNA may be found

A. only in the nucleus.
B. only in the nucleus and mitochondria.
C. only in the nucleus and rough ER.
D.in the nucleus, mitochondria, and rough ER.
D
If plant cells are grown on media containing radioactively labeled thymine for one generation, where will radioactively labeled macromolecules be detected?

A. only in the nucleus
B. only in the nucleus and mitochondria
C. only in the nucleus and chloroplasts
D. in the nucleus, mitochondria, and chloroplasts
D
The chemical reactions involved in respiration in prokaryotic and eukaryotic cells are virtually identical. In eukaryotic cells, ATP is synthesized primarily on the inner membrane of the mitochondria. In light of the endosymbiont theory for the evolutionary origin of mitochondria, where is most ATP synthesis likely to occur in prokaryotic cells?

A. on the endoplasmic reticulum
B. in the cytoplasm
C. on the nucleoid membrane
D. on the plasma membrane
A
The evolution of eukaryotic cells most likely involved

A. endosymbiosis of an oxygen-using bacterium in a larger host cell; the endosymbiont evolved into mitochondria.

B. endosymbiosis of an oxygen-using photosynthetic bacterium in a larger host cell; the endosymbiont evolved into mitochondria.

C. evolution of an
endomembrane system and subsequent evolution of mitochondria from a portion of the Golgi.

D. endosymbiosis of an oxygen-using scavenger bacterium in a larger host cell; the endosymbiont evolved into lysosomes.
E
Which of the following functions is NOT associated with the cytoskeleton in eukaryotic cells?


A. the beating of cilia or flagella

B. determining the shape of animal cells

C. the contraction of muscle cells in animals

D. maintaining the position of the nucleus in the cell

E. movement of RNA molecules from the nucleus to the cytoplasm
E
Which organelles or structures are absent in plant cells?

A. mitochondria
B. microtubules
C. peroxisomes
D. Golgi apparatus
E. centrosomes
D
Motor proteins provide for molecular transport of materials in cells by interacting with what types of cellular structures?

A.membrane proteins

B. cellulose fibers in the cell wall

C. the extracellular matrix

D. cytoskeletal structures

E. the nuclear envelope
transmembrane protein
A protein that spans the phospholipid bilayer one or more times is
C
A primary function of cholesterol in the plasma membranes of some animals is to

A. make the membrane more rigid, allowing it to resist pressure from outside the cell.

B. facilitate the removal of hydrogen atoms from saturated phospholipids.

C. enable the membrane to stay fluid more easily when the temperature drops.

D. facilitate cell-cell interactions by binding to receptors on neighboring cells.
phosphilipids and proteins
The primary structural components of the cell membrane are
A
Water passes quickly through cell membranes because

A. it moves through aquaporin channel proteins.

B. water movement is tied to ATP hydrolysis.

C. it moves through hydrophobic channels.

D. the bilayer is hydrophilic.

E. it is a small, nonpolar molecule.
Amino acid
Which of the following would diffuse through the lipid bilayer of a plasma membrane most slowly, if at all?


CO2
water
an amino acid
O2
glucose
A
Which of the following is a characteristic feature of a carrier protein in a plasma membrane?

A. It exhibits a specificity for a particular type of molecule.

B. It is a peripheral membrane protein.

C. It works against a concentration gradient.

D. It requires the expenditure of cellular energy to function.
D
Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this most probably mean?

A. Proton pumps are an essential feature of all cell membranes.

B. Cells of each domain evolved proton pumps independently when oceans became more acidic.

C. Proton pumps must have evolved before any living organisms were present on Earth.

D. Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.
A
The sodium-potassium pump generates the following concentration gradients across the plasma membrane:

A. low [Na+] and high [K+] inside the cell and high [Na+] and low [K+] outside.

B. high [Na+] and low [K+] inside the cell and low [Na+] and high [K+] outside.

C. high [Na+] and [K+] inside the cell and low [Na+] and [K+] outside.

D. low [Na+] and [K+] inside the cell and high [Na+] and [K+] outside.
C
The sodium-potassium pump is called an electrogenic pump because it

A. pumps hydrogen ions out of the cell.

B. ionizes sodium and potassium atoms.

C. contributes to the membrane potential.

D. pumps electrons across the plasma membrane.
membrane potential
What is the voltage across a membrane called?
D
Which of the following membrane activities requires energy from ATP hydrolysis?

A. movement of water into a cell through aquaporins

B. facilitated diffusion of chloride ions across the membrane through a chloride channel

C. movement of glucose
molecules into a bacterial cell from a medium containing a higher concentration of glucose than inside the cell

D. movement of sodium ions from a lower concentration in a mammalian cell to a higher concentration in the extracellular fluid

E. movement of carbon dioxide out of a paramecium
B
The difference between pinocytosis and receptor-mediated endocytosis is that

A. pinocytosis requires cellular energy, but receptor-mediated endocytosis does not.

B. pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis is highly selective.

C. pinocytosis brings only water molecules into the cell, whereas receptor-mediated endocytosis brings in other molecules as well.

D. increases the surface area of the plasma membrane, whereas receptor-mediated endocytosis decreases the plasma membrane surface area.

E. pinocytosis can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot.
C
Which of the following statements about diffusion is correct?

A. It is very rapid over long distances.

B. It is an active process in which molecules move from a region of lower concentration to one of higher concentration.

C. It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.

D. It requires an expenditure of energy by the cell.

E. It is a passive process in which molecules move from a region of lower concentration to a region of higher concentration.
E
Submerging a plant cell in distilled water will result in


A. lysis of the cell membrane.

B. plasmolysis of the cell.

C. bursting of the cell.

D. the cell becoming flaccid.

E. the cell becoming turgid.
E
Which of the following statements correctly describes the normal tonicity relationships between typical plant and animal cells and their respective environments?

A. Animal cells are generally in an isotonic solution, and plant cells are generally in a hypertonic solution.

B. Animal cell are generally in a hypertonic solution, and plant cells are generally in an isotonic solution.

C. Animal cells are generally in a hypertonic solution, the plant cells are generally in a hypotonic solution.

D. Animal cells are generally in a hypotonic solution, and plant cells are generally in an isotonic solution.

E. Animal cells are generally in an isotonic solution, and plant cells are generally in a hypotonic solution.
A
In receptor-mediated endocytosis, receptor molecules are initially localized on the outer surface of the plasma membrane. Where do the receptors end up following endocytosis?

A. on the inside surface of a vesicle

B. the outer surface of a vesicle

C. on the outer surface of the nucleus

D. on the inside surface of the Golgi apparatus

E. on the inside surface of the plasma membrane
B
A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water equal to the volume of blood lost − is transferred directly into one of his veins. What will be the most probable result of this transfusion?


A. The patient's red blood cells will shrivel up because the blood fluid has become hypotonic compared to the cells.

B. The patient's red blood cells will swell because the blood fluid has become hypotonic compared to the cells.

C. It will have no unfavorable effect as long as the water is free of viruses and bacteria.

D. The patient's red blood cells will shrivel up because the blood fluid has become hypertonic compared to the cells.
A
The fluid mosaic model of the membrane proposed that membranes

A. consist of protein molecules embedded in a fluid bilayer of phospholipids.

B. consist of a phospholipid bilayer between two layers of hydrophilic proteins.

C. of a phospholipid bilayer composed of a variety of fatty acids.

D. consist of a single layer of phospholipids and proteins.
O2
Which of the following would diffuse through the lipid bilayer of a plasma membrane most rapidly?

an amino acid
glucose
starch
Na+
O2
A
Which of the following is most likely true of a protein that cotransports glucose and sodium ions into the intestinal cells of an animal?

A. Transport of sodium ions down their electrochemical gradient facilitates the transport of glucose against its concentration gradient.

B. Transport of glucose against its concentration gradient provides energy for uptake of sodium ions against the electrochemical gradient.

C. Sodium and glucose bind to the same site on the cotransporter.

D. Sodium ions can be transported whether or not glucose is present outside the cell, but glucose transport requires cotransport of sodium ions.

E. Following transport of sodium ions into the cell, the cotransporter can also transport potassium ions out of the cell.
B
Which is not a function of proteins?

A.help make up membranes

B.carry the code for translation from the nucleus to the ribosome

C.bind to hormones (hormone receptor)

D.can be hormones

E.speed chemical reactions
E
Which is the least metabolically active kind of protein?

A.receptor protein

B.contractile protein

C.enzymatic protein

D.hormonal protein

E.structural protein
A
Which level of protein structure is most immediately encoded in DNA?

A.primary

B.secondary

C.tertiary

D.quaternary

E.There is no difference between the four answers
C
How does RNA differ from DNA?

A.DNA encodes hereditary information; RNA does not.

B.DNA forms duplexes; RNA does not.

C.DNA contains thymine; RNA contains uracil.

D.DNA contains five bases; RNA contains four.

E.all of the above
B
What is incorrect about the following statement? "The tRNA sequence reads ATGCCATGG...."

A.tRNA is made of amino acids.

B.tRNA has U in place of T.

C.tRNA is not linear.

D.A and C

E.None of the choices is correct.
A
If you located a single-stranded piece of nucleicacid in a cell, what would it be made of?

A.nucleotides

B.amino acids

C.fatty acids

D.sugars

E.glycerol
B
Which sugar is most important for making RNA?

A.glucose

B.ribose

C.frostose

D.glyceraldehyde

E.sucrose
E
For which of the following could genomics be used?

A.studying disease

B.conservation work

C.predicting future medical problems

D.evolutionary studies

E.all of the above
C
Which provides the most compact energy storage?

A.proteins

B.carbohydrates

C.lipids

D.nucleic acids

E.All provide about the same amount of energy stored per unit volume.
D
For what is water most needed when digesting food?

A.dehydration reactions

B.temperature reduction

C.solubility

D.hydrolysis reactions

E.none of the above
A
When observing the synthesis of a biological macromolecule, of what should you see more appear?

A.water

B.amino acids

C.alcohol

D.ions

E.fatty acids
D
Which cellular structure is common to all three domains of life?

A.nucleus

B.endoplasmic reticulum

C.mitochondria

D.ribosomes

E.endocytotic vesicles
A
Enzymes responsible for biosynthesis of membrane lipids would be located in what part of the cell?

A.endoplasmic reticulum

B.nucleus

C.lysosomes

D.Golgi

E.plasma membrane
E
Which of the following is not an argument for the theory that mitochondria and chloroplasts evolved from prokaryotic endosymbionts?

A.Mitochondria and chloroplasts have double membranes.

B.Mitochondria and chloroplasts have their own ribosomes.

C.Mitochondria and chloroplasts have their own DNA.

D.The mitochondrial and chloroplast genomes are circular.

E.All of the above support the endosymbiotic theory.
D
Autophagy removes old, damaged organelles like mitochondria. Which organelle is most critical for autophagy?

A.smooth ER

B.peroxisomes

C.rough ER

D.lysosomes

E.Golgi apparatus
D
What is the correct order for secretion?

A.rough ER, endosome, Golgi, smooth ER

B.rough ER, Golgi, smooth ER, exocytosis

C.smooth ER, rough ER, exocytosis, Golgi

D.rough ER, Golgi, transportvesicle, exocytosis

E.rough ER, Golgi, endosome, exocytosis, transport vesicle
C
Taxol, which is used in fighting breast cancer, prevents depolymerization of microtubules. What cellular function might taxol interfere with most in fighting cancer?

A.maintaining cell shape

B.cell motility (cilia or flagella)

C.chromosome movements in cell division

D.cell division (cleavage furrow formation)

E.cytoplasmic streaming
A
Which kind of cells make plasmodesmata?

A.plant cells

B.animal cells

C.bacterial cells

D.A-C

E.B and C
B
Which kind of cells make tight junctions?

A.plant cells

B.animal cells

C.bacterial cells

D.A-C

E.A and C
D
If you were studying frog eggs, what would be most useful for visualizing them?

A.unaided eye

B.light microscope

C.electron microscope

D.A and B

E.A and C
E
If you were studying typical bacteria, what would be most useful for visualizing them?A.unaided eye

B.light microscope

C.electron microscope

D.A and B

E.B and C
B
Which is not part of a prokaryotic cell?

A.nucleoid

B.chloroplast

C.ribosome

D.plasma membrane

E.cell wall
A
Which is not part of a eukaryotic cell?

A.nucleoid

B.chloroplast

C.ribosome

D.plasma membrane

E.peroxisome
A
If you fluorescently labeled a protein and found it ended up in the nucleus, through what must it have passed?

A.pore complex

B.nucleolus

C.chromatin

D.endoplasmic reticulum

E.not necessarily any of these
C
f you placed fluorescently labeled protein outside an animal cell, after uptake for digestion, where would it be?

A.rough ER

B.smooth ER

C.lysosome

D.peroxisome

E.mitochondrion
B
If you were examining a plant cell, what kind of vacuole would you find?

A.contractile

B.central

C.food

D.A-C

E.A and C
D
If you were working in a cave and discovered an unusual carnivorous plant, what might this plant lack at the cellular level yet still be able to survive using carnivory?

A.ER

B.nucleus

C.mitochondrion

D.chloroplast

E.peroxisome
B
If you applied a drug to block mitochondrial function, what would an affected cell lack most?

A.protein

B.ATP

C.enzymes

D.vesicles

E.membranes
D
The cell junctions respectively that exclude the passage of water between cells, maintain tissue form and strength, and allow the exchange of small molecules between cells are:

A.desmosomes, tight junctions and gap junctions.

B.tight junctions, gap junctions, and tight junctions

C.gap junctions, tight junctions, and desmosomes.

D.tight junctions, desmosomes, and gap junctions
B
Which molecule will diffuse most quickly across a lipid bilayer membrane?

A.H2O

B.O2

C.H2PO4

D.glucose

E.Na
D
Cells such as bacteria are taken up by other cells such as immune cells by which process?

A.pinocytosis

B.exocytosis

C.receptor-mediated endocytosis

D.phagocytosis

E.facilitated diffusion
D
Movement of water out of a cell that has been placed in a hypertonic solution is

A.active transport.

B.passive transport.

C.diffusion.

D.B and C.

E.A and C.
A
If you placed an algal cell that had been living in a marine aquarium with oceanic fish into a glass of pure water, what would happen?

A.The cell would take up water.

B.The cell would turn on cell signaling.

C.Water would bind to receptors.

D.The cell would lose water.

E.none of the above
E
You are observing a newly discovered form of protist, and you see an organelle suddenly decrease in volume. What has happened?

A.The cell was osmoregulating.

B.The cell used its contractile vacuole.

C.The cell was counteracting osmosis.

D.The cell was avoiding bursting.

E.All of the choices are correct.
D
If you were studying a cell undergoing lots of active transport, which nucleotide would you expect to find in greatest abundance?

A.GTP

B.UTP

C.TTP

D.ATP

E.CTP
E
A living cell has a gradient across its membrane that is which of the following?

A.electrical

B.physical

C.light-driven

D.chemical

E.A and D
C
If you place a culture of animal cells (called fibroblasts) into a container filled with molecules of red dye that have a strong negative charge, and the dye ends up inside the cell, what is the most likely explanation for the uptake?

A.osmosis

B.phagocytosis

C.pinocytosis

D.active transport

E.None of the answers is correct.
E
Chemical analysis of a cellular membrane would normally reveal the presence of

A.sugars.

B.proteins.

C.lipids.

D.nucleic acids.

E.A-C.
D
In which case would osmosis occur?

A.a red blood cell in an isotonic solution

B.a beaker of water with salt dissolved and evenly mixed in it

C.a cell coated with an impermeable plastic coating

D.a skin cell in a hypotonic solution

E.none of the above
B
Not a function of the Smooth ER?

A. the addition of a water molecule

B. the addition of nitrogen atom

C. the release of a carbon dioxide molecule

D. the release of a water molecule
C
Your membrane is selectively permeable, this means that it selects what it wants to let pass through it. What kind of molecules can easily pass through it and why?

A. ionic molecules, because they have no charge

B. polar molecules, because only they can fit through transport proteins

C. non-polar molecules, because the interior of the membrane is hydrophobic

D. none of these above
Beta helix
Which of the following is NOT related to protein structure?

Disulfide-bridges
Alpha helix
Beta pleated sheets
Beta helix
D
What is the flow of particles that pass through the sodium potassium-pump

A. 3NA+ into the cell and 2K+ leaving the cell

B. 3K+ into the cell and 2NA+ leaving the cell

C. 2NA+ into the cell and 3K+ leaving the cell

D. 2K+ into the cell and 3NA+ leaving the cell
passive transport and diffusion
Movement of water out of a cell that has been placed in a hyper tonic solution is
Golgi apparatus
What structure produces and modifies polysaccharides that will be secreted?
Peroxisomes
John went out partying last night, which organelles are working the hardest?
Mitochondria
Suppose a young boy is always tired and fatigued, suffering from a metabolic disease. Which of the following organelles is most likely involved in this disease?
liver and muscle cells
Where do humans and other vertabrates store glycogen?
Chitin
Which polysaccharide provides structural support for the cell, and its found on the exoskeleton, but does not act as storage support?
Smooth ER
Muscarine is a toxin found in a certain fungi, which of the following would help detoxify muscarine if found on animal or plant cells?
Lysosomes
Part of the cell that hydrolyzes materials taken into the cell and recycle materials.
Digestion
Not a function of proteins
Starch
What can amalyse break down?
cotransport
The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. Phosphate import depends in a pH gradient across the membrane -- ore acidic outside the cell than inside the cell. Phosphtae transport is an example of
B
Many cold water fish are known to excellent sources of omega-3 fatty acids (a type of polyunsaturated fatty acid)

A. The absence of double bonds on the unsaturated fatty acids prevents cell membranes of fish from becoming too rigid.

B. The presence of double bonds on the unsaturated fatty acids prevents the cell membranes of the fish from becoming too rigid.

C. The presence of double bonds in the unsaturated fatty acids prevents the cell membranes of the fish from becoming too fluid.
C
Three stages of cell signaling are:

A. activation, co transport, release

B. endocytosis, exocytosis, release

C. recpetion, transduction, response

D. activation, transduction, response