192 terms

Bio104 First Exam

STUDY
PLAY

Terms in this set (...)

Which one of the following is characteristic of both living organisms and non-living material?
follow natural laws
Which type of amino acid side chain would NOT be attracted to one of the dipoles of a water molecule?
nonpolar
The three-dimensional structure of a functional protein composed of a single polypeptide chain is referred to as the ____________ structure
tertiary
Secondary structure is characterized by which one of the following types of interactions?
hydrogen bonding within the peptide backbone
Two types of secondary structure interactions are referred to as:
α-helix and β-sheet
Which one of the following can contribute to a protein's tertiary structure?
E. All of these choices are correct.
Answers:
A. ionic bonding
B. van der Waal's forces
C. covalent bonding
D. hydrogen bonding
E. All of these choices are correct.
The unfolding of a protein by heat or chemical treatment is referred to as
denaturation
The genetic code is
redundant
During protein synthesis, a peptide bond is formed
A. between side chains of the amino acid and the C-terminal amino acid residue of the peptide


B. between the carboxyl group of an amino acid and the amino group of the peptide


C. between amino groups of the amino acid and peptide
D. between the carboxyl group of the peptide and the amino group of an amino acid
E. between carboxyl groups of the amino acid and peptide
All of these processes occur in the nucleus of eukaryotic cells EXCEPT
translation
Which one of the following amino acids is capable of forming a disulfide linkage4
cysteine
Secondary structures are stabilized by which type of interaction?
hydrogen bonding
Which one of the following is specific to the synthesis of only one type of protein?
A. a transfer RNA
B. an aminoacyl tRNA synthetase
C. a messenger RNA
D. an elongation factor
E. a ribosome
Translation
synthesizes a peptide with an amino acid sequence that corresponds to the sequence of codons in an mRNA
What is the sequence of the anticodon for the codon GGC?
5'-GCC-3'
The covalent bonds between adjoining amino acid residues in a protein are
peptide bonds
Which is responsible for secondary structure of proteins?
hydrogen bonds involving the partial positive and partial positive charges in the polypeptide backbone
Which is the primary structure of a protein?
the amino acid sequence
Which is a property of quarternary protein structure?
associations of more than one peptide
Which underlies tertiary protein structure
interactions among the side chains of amino acid residues
Which plays a direct role in protein synthesis?
ribosome
This is a segment of the coding sequence of a gene encoding a protein: 5'-GCGGAT-3' If the gene were to be transcribed and the message translated, what number of amino acids would the gene segment correspond to?
2
Just like bacteria, mitochondria and chloroplasts contain DNA. Mitochondria and chloroplasts can also synthesize a handful of proteins. Given this, what must mitochondria and chloroplasts contain?
E. all of the above
Answers:
A. rRNA
B. mRNA
C. ribosomes
D. tRNAs
E. all of the above
The genetic code is said to be redundant, or degenerate, because
multiple codons can specify the same amino acid
Which is a carboxyl group?
D. -COOH
Which of these are encoded by genes but do not participate in translation?
RNAs in spliceosomes
Which has an N-terminal and a C-terminal?
E. A and B
Answers:
A. a peptide
B. a protein
C. a single strand of DNA
D. an RNA strand
E. A and B
Which is the RNA complement to 5'-ATCG-3' ?
5'-CGAU-3'
Which has promoter regions?
DNA
Which has a 5' end and a 3' end?
E. A and B
Answers:
A. a DNA strand
B. an RNA strand
C. a protein
D. a polysaccharide
E. A and B
True or false: during transcription of a given protein-coding gene, both strands are used as template.
false
Where does the energy come from to add a uracil to the 3' end of a transcript?
the hydrolysis of pyrophosphate from the incoming UTP molecule
RNA polymerase can do which one of the following?
RNA polymerase is capable of all of these activities.
The type of RNA that physically interacts with a ribosome, providing the sequence information for a specific protein, is abbreviated:
mRNA
Which one of the following types of post-transcriptional modification is common in eukaryotes
D. All of these choices are correct.
Answers:
A. polyadenylation
B. intron removal
C. 5' cap addition
D. All of these choices are correct.
Alternative splicing allows for:
A. two or more different proteins to be made from a single processed mRNA.
B. multiple genes to be used to code for a single polypeptide chain.
C. enhanced recognition of an mRNA by a ribosome.
D. increased stability of a mature mRNA.
E. different polypeptides to be encoded by a single gene.
True or false: Muscle cells make different proteins than nerve cells because they have different sequences of DNA.
false
Which of the following processes occur in the nuclei of eukaryotic cells?
DNA replication and transcription
Which one of the following represents a standard Watson-Crick base pair interaction?
G-C
An RNA transcript is synthesized in which direction?
5' to 3'
Which one of the following is not a way in which RNA differs from DNA?
RNA nucleotides can possess only a single phosphate group; DNA nucleotides have one, two, or three phosphate groups.
Which one of the following types of RNAs carries information for making a single type of protein?
messenger RNA
Which of the following correctly indicates the complementary base pairing of adenine in DNA and RNA?
adenine with thymine in DNA and with uracil in RNA
Can you determine the per cent adenine content of an RNA strand if you know the percentage of guanine in the RNA strand?
no
In regard to the previous item, what feature of DNA allows determination of the percentage of guanine if the percentage of adenine is known?
in contrast to the single-stranded RNA, for a double stranded DNA, if you know the percentage of A, you know the percentage of T. You also know that half of the remainder will be C and the other half will be G
In the process of transcription
an RNA strand that is complementary and antiparallel to a DNA template is synthesized as ribonucleotides base pair to the template and are covalently incorporated into the RNA molecule
Deoxyribonucleic acid has function in
. A and B
When a mixture of debris from killed virulent bacteria and living non-virulent bacteria are injected into mice
the mice are killed because the non-virulent bacteria are transformed into virulent bacteria
Non-virulent bacteria can be prevented from being transformed into virulent bacteria if the debris from heat-killed virulent bacteria is first treated with
DNase
The central dogma of molecular biology states that information flows from:
DNA to RNA to protein
Which one of the following is least likely to be found in a nucleotide?
a side chain
In the DNA sequence 5'-TGAC-3', the phosphodiester linkage between the guanine and the adenine connects
the 3' end of the guanine to the 5' end of the adenine
What is the DNA complement of this strand of DNA?
5'-ATCG-3'
5'-CGAT-3
What is the DNA complement of this strand of DNA?
5'-CGAT-3'
5'-ATCG-3'
How does the original DNA segment in #7 compare to the complement of its complement?
same
The strands in a DNA double helix are
A and B
Which one of the following represents an actual Watson-Crick base pair with the largest number of hydrogen bonds?
cytosine and guanine
The DNA of organism that contains 30% adenine would contain ____________ guanine.
20%
Which one of the following activities would least likely be found in a topoisomerase?
adding nucleotides to the end of a DNA strand
True or false: In the sequence AGGCCT, an available phosphate group would be found at the 5' end of the nucleotide labeled "T."
false
In a deoxyribonucleotide, what chemical group is found at the 2' carbon of the sugar component?
..
Arrange the following in order from smallest to largest.
Nucleoside, nucleotide, gene, genome
The fact that DNA replication occurs in virtually the same way in all organisms reflects:
its evolution early in the history of life.
In DNA replication, each individual parent strand acts as a _____ for the synthesis of a _____.
template strand; daughter strand that is the reverse complement of the template
When we say that DNA replication is semiconservative, we mean that:
when DNA is replicated, each new double helix contains one parental strand and one newly synthesized daughter strand.
A new nucleotide can only be added to the ____ of a growing DNA strand. DNA therefore always grows in the _____ direction.
3'; 5' to 3'
The leading strand is the daughter strand that has its ____ end pointed toward the replication fork and is therefore synthesized ______.
3'; continuously
The lagging strand is the daughter strand that has its ____ end pointed toward the replication fork and is therefore synthesized ______.
5'; in a series of segments
As DNA is replicated, the leading strand will have ____ RNA primer(s) and the lagging strand will have ____.
one; many
In contrast to linear DNA, circular DNA replication typically:
has a single origin of replication.
Energy is required in order to add a nucleotide to the growing strand of DNA during replication. From where does that energy come?
hydrolysis of a phosphoanhydride bond in the incoming nucleotide
Why is it that primers are needed for DNA replication?
DNA polymerase can only add nucleotides to an existing chain, it cannot initiate synthesis of a new strand
What provides the energy required to form phosphodiester bonds in the DNA sugar-phosphate backbone?
energy released from breaking the phosphoanhydride bond between phosphate groups of a deoxynucleotide
When a DNA double helix is replicated, the resulting DNA double helices
each contain one parent strand and one daughter strand
What does an RNA primer provide that is essential to the ability of DNA polymerase to replicate DNA in cells?
DNA polymerase requires a free 3' hydroxyl group onto which to covalently link a deoxynucleotide
A genetic variation is transmitted from generation to generation to generation by
replication
Why is the G bond with C stronger than the A bond with T in standard base-pairing?
there are more hydrogen bonds in the G/C pair than in the A/T pair
Which of these carries the genetic information, transmitted from generation to generation, that can serve as a template for transcription?
DNA
A mutated gene that is passed from generation to generation is encoded by
DNA
A pair of shared valence electrons is referred to as a(n):
covalent bond
The ability of atoms to attract electrons is referred to as:
electronegativity
True or false: an ionic interaction, such as the interaction between Na+ and Cl-, is considered a covalent bond.
false
Which one of the following represents the pH of a solution with the highest concentration of hydrogen ions?
1.0
Which one of the following properties of water is primarily responsible for the ability of trees to draw water up from the roots to the leaves?
..
Which of the following components of an amino acid differs from one amino acid to another?
the side chain
The linkage of one amino acid to another amino acid in a protein is most accurately referred to as a(n)
peptide bond.
If you isolate a single nucleotide from a nucleic acid chain and determine that the nitrogenous ring structure is cytosine, you could say with certainty that the nucleotide could have come from:
either DNA or RNA.
In the process of RNA or DNA polymerization, a phosphodiester bond is formed between:
nucleotides
A primary role of triglycerides (a.k.a. triacylglycerols) is
energy storage.
Which one of the following types of fatty acids would be likely to have the lowest melting temperature?
short tails and low saturation
Exposure of purified phospholipids to water results in the spontaneous formation of:
lipid bilayers.
A polar bond is due to:
a slight positive or negative charge due to unequal sharing of electrons
The class of organic molecules defined by a physical property rather than a structure are the:
lipids
True or false: Adjacent nucleotides in an RNA chain are held together by hydrogen bonding.
false
Lipid bilayers spontaneously form to orient the _____________ tails _____________ to minimize their contact with water.
hydrophobic; inside
Which of the following contains nitrogen?
A and B
In an atom that is NOT an ion, which of the following must be true?
The number of electrons equals the number of protons.
Two of the main ingredients in plant fertilizer are phosphorus and nitrogen. These elements are required for the synthesis of __________________, respectively, in the cells of the plants.
DNA and proteins
What is the chemical basis for water's role as the universal solvent?
b and c.
Which of the following are covalent bonds?
all except D
Consider the structure and function of DNA. Which of the following statements is true?
If the sequence of one DNA strand is known, then the sequence of the other strand can be determined.
A scientist does a chemical analysis of an unknown sample and finds that the sample contains carbon, hydrogen, and oxygen among other atoms. Is the sample from a living organism?
there's no way to know from the information provided
Fluorine can participate in a reaction in which it completely accepts an electron from another atom and is not involved in a covalent bond, creating fluoride. What is the electrical charge of fluoride?
negative
If cellular matter is dried, so it contains only trace amounts of water, which element contributes most to the remaining mass?
..
Which of these is a non-covalent bond
hydrogen bond
The covalent bonds between adjoining monosaccharides in a polysaccharide are
glycosidic bonds
The covalent bonds between adjoining deoxyribonucleotides in DNA are
phosphodiester bonds
The covalent bonds between adjoining ribonucleotides in RNA are
phosphodiester bonds
The noncovalent bonds that attract one single strand of DNA to its reverse complement strand are
hydrogen bonds
Why is DNA more stable than RNA?
The presence of a 2' hydroxyl group on each ribonucleotide in the RNA makes the molecule reactive and subject to degradation
Long, saturated fatty acid tails ______________ lipid mobility and ______________ membrane fluidity.
reduce; decrease
Which types of cells have plasma membranes?
all of the above
Which one of the following would be least likely to cross a lipid bilayer?
ATP (this is a ribonucleotide triphosphate)
The sodium/potassium pump is an example of:
an antiporter.
Which one of the following is not considered part of the cytoplasm?
the nucleus
The process of a vesicle fusing with the plasma membrane and depositing its contents into the extracellular space is most specifically referred to as:
exocytosis
RNA molecules are transported from the nucleus to the cytoplasm in eukaryotes through
nuclear pore complexes.
Protein synthesis can occur in all of these subcellular locations EXCEPT
nucleus
True or False: purified phospholipids will gather together and form membranes only if the appropriate enzyme is present.
false
What type of molecule would you not expect to find as a component of a cell's membrane?
Nucleic acid
The interior region of a phospholipid bilayer can be characterized as being
hydrophobic.
A phospholipid molecule in a membrane can:
both spin (rotate around its vertical axis) and move side-to-side (lateral movement).
An amphipathic molecule is one that:
contains both polar and nonpolar regions.
Predict how phospholipids would arrange themselves if they were placed into a nonpolar solution.
The phospholipid tails would orient toward the solution
What factors are required for facilitated diffusion to occur?
All of the answer options are correct
The movement of water into or out of a cell is an example of
osmosis
Why does active transport require ATP energy?
to allow the movement of molecules from low to high concentration
To pump Na+ and K+ against their concentration gradients, the Na+/K+ ATPase harnesses energy from the exergonic reaction of hydrolysis of adenosine triphosphate (ADP) to adenosine diphosphate (ADP) and an inorganic phosphate (Pi). What prevents ATP from being completely depleted from a cell?
there are metabolic pathways that can couple exergonic reactions to the formation of a new phosphoanhydride bond on ADP to regenerate ATP (ADP + Pi --> ATP)
A cell's plasma membrane contributes to homeostasis by:
acting as a selective barrier
Which of the following molecules would not easily diffuse across a plasma membrane without participation of a protein?
large polar molecules
What is secondary active transport?
the use of the electrochemical gradient of one molecule to move a second molecule, when primary active transport maintains the electrochemical gradient
During osmosis, water moves from a region of _________ to a region of _________.
. low solute concentration; high solute concentration
All cells have:
genetic information
Which of the following is part of the endomembrane system of a eukaryotic cell?
All of the answer options are correct.
Movement of cellular material from the endoplasmic reticulum to the outside of the cell is an example of
exocytosis.
Imagine you have radioactively labeled a protein in the lumen of the endoplasmic reticulum. Where would you predict the labeled protein might end up?
All of the answer options are correct.
Synthesis of a protein destined to function in the nucleus occurs:
in the cytosol.
Which of the following molecules would most likely require a transport protein to cross the plasma membrane of a red blood cell?
C6H12O6
Some diseases can result from defective transport across the membrane. For example, cystic fibrosis results from a chloride ion transporter that does not function. Which of the following would be affected when this transporter does not function?
Both a and b
Which of the following accurately describes the path travelled by a new protein as it is synthesized and released from the cell
cytosol → ER → Golgi → transport vesicle → plasma membrane → external environment
Lipid portions of molecules
A and C
Intravenous fluids generally contain NaCl or other solutes so that the concentration of dissolved molecules in the fluid is similar to the concentration of dissolved molecules in the bloodstream. Why is this?
this prevents the osmotic fluid shifts into cells that would occur if the intravenous fluid were hypotonic
Blood glucose concentration after a meal containing carbohydrate rises above 5 mM in humans. Glucose concentration inside muscle cells is not much higher than 0 mM. If muscle cells have facilitative glucose carriers in their plasma membranes, which way would glucose diffuse after a meal?
nto muscle cells
Amphipathic lipids can form lipid bilayers in water because
C and D
The fluorescence recovery after photobleaching (FRAP) technique has been used to demonstrate that
lipids and unanchored proteins diffuse freely laterally around the lipid bilayer in a fashion consistent with the Fluid Mosaic Model of membrane composition
A protein pump that requires ATP hydrolysis to provide energy to move a molecule across a membrane is involved in
primary active transport
What is aquaporin?
an H2O channel
A lipid bilayer would be least fluid if the membrane's lipid groups were exclusively of this type:
saturated fatty acids
An mRNA is transcribed in the nucleus of a eukaryotic cell. Where is this mRNA translated?
In the cytosol
Large molecules, such as mRNAs and tRNAs, are able to exit the nucleus
by moving through pores in the nuclear envelope
Which of the following does NOT occur in prokaryotes?
protein trafficking through the endomembrane system
True or False: Observations allow scientists to draw tentative explanations called hypotheses
True
An explanation supported by a large body of observations and experimentation is referred to as a
theory
which one of the following is characteristic of both living organisms and non-living organisms?
obeying the basic laws of chemistry and physics
which one of the following is a primary component of both living organisms and the earth's crust?
oxygen
when small molecules are linked together to form larger molecules, the increase in entrophy typically comes from
heat
which one of the following scientists tested the hypothesis that microorganisms can arise by spontaneous generation?
Pasteur
which of the following types of organisms are based on cellular life
all living organisms
The ostrich egg is composed of how many cells
1
transcription is the process by which
RNA is synthesized as an antiparallel complement to a single strand of DNA
Translation is the process by which
Proteins are synthesized when base pairing between a codon of mRNA and an anticodon of a tRNA brings an amino acid into position for covalent attachment to a peptide
The DNA sequence that corresponds to a specific protein product is known as a
gene
True or False: Mutations always result in the death of the organism which acquires them
false
Cells with a nucleus are called ______; cells without a nucleus are called _____.
eukaryotes/prokaryotes
Which one of the following types of organisms most closely resembles the original prokaryotes
bacteria
________ is an important reactant in numerous organismal chemical reactions because of its property of releasing energy when some of its covalent bonds are broken and metabolic pathways for reforming these bonds, replenish the
ATD
Variation among individuals in a species is usually caused by
both environmental and genetic variation
The primate most closely related to humans is the
chimpanzee
True or False: Interactions between organisms can influence the evolution of particular traits
True
True or False: a tentative, testable explanation based on observation is referred to as a hypothesis
True
True or False: in the context of the scientific method, the words theory and hypothesis can be used interchangebly
False
a single experiment or observation can _________ a hypothesis
reject or support it
in the scientific method, hypotheses lead most directly to
predictions
which of the following statements about hypotheses is wrong?
hypotheses that provide reasonable explanations do not need o be tested
True or False: because water is so abundant on earth, oxygen and hydrogen make up the majority of the known matter of the universe
False
Which one of the following elements is found in non-living systems but not found in more than trace amounts in living systems?
silicon
In Pasteur's experiment showing that living organisms arise from other living organisms, which one of the following statements most accurately describes Pasteur's hypothesis?
If microbes arise from non-living matter, they should appear spontaneously in sterile broth
True or False: organisms from all classifications of life are composed of cells
true
True or False: organisms that posses a nucleus are called prokaryotes. Organisms that do not posses a nucleus are called eukaryotes.
False
Which one of the following entities does not posses the ability to synthesize its own proteins
a viral particle
Which one of the following represents the information as described by the central dogma of molecular biology
Information in DNA is a template on which a new mRNA is synthesized during transcription. The new mRNA contains information that corresponds in antiparellel fashion to the DNA template strand. Translation of the mRNA produces a peptide with an amino acid sequence that corresponds to the sequence of three base codons in the mRNA
Evolution is the change in the genetics of a _____ over time
population
Which of the following statements about evolution is incorrect?
Evolution led to the branches in the tree of life, but development of the organisms within a single branch has subsequently remained constant
Redi generated a tentative explanation for the origins of living entities that made the predictions that maggots were derived from flies and not spontaneously generated. At the time of his experiment, his tentative explanation was a
hypothesis
which best describes the statement "when there is variation within a population of organisms, and when that variation can be inherited, the variants best able to grow and reproduce in a particular environment will contribute disproportionately to the next generation leading to a change in the population over time, or evolution.
This is a general explanation of an aspect of the natural world supported by a large body of experiments and observations
Which is most consistent with evolution by natural selection
genetic variation among individuals influences ability to reproduce, leading to a change in the genes in a population over generations
A scientist forms a hypothsis that leads to the prediction that a high level of a certain protein causes cells to become cancerous. One treats cells so that they contain a high level of the protein but then finds that the cells do not become cancerous. What's her next step?
She should reject her hypothesis in its current form
which of the following is a living organism
a cell
which is not a part of a theory
a rise in mean air temp is related to poor apple quality
which most likely played key roles in evolution of antibiotic resistance bacteria?
1.) genetic variation in bacteria that occurred before exposure to antibiotic
2.) selection
the central dogma of molecular biology often depicted by a model of information flow such as this DNA--RNA--protein. In this model, the arrow between DNA and RNA means that
1.) enzymes synthesize new RNA molecules that are the reverse compliments of DNA strands
2.) base pairing of ribonucleotides to existing DNA strands is the basis for determining the base sequence of new RNA strands
The central dogma of molecular biology often is depicted by a model of information known such as this: DNA--RNA--protein. In this model the arrow between RNA and protein means that
1.) in the process of translation a protein is produced with an amino acid sequence that corresponds to the sequence of 3 base codons in an mRNA
2.) translation produces a new protein molecule and the mRNA that was translated still exists