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Biology Exam 2

Terms in this set (77)

When ATP releases its energy, it forms:
AMP
ADP
Pi-
both AMP and Pi-
both ATP and Pi-
both ATP and Pi-
The products of exergonic pathways are usually:
Lower in energy
Higher in energy
Larger and higher in energy
Smaller and higher in energy
Smaller and lower in energy
Smaller and lower in energy
During enzyme-catalyzed reactions, substrate is a synonym for:
End product
Byproduct
Enzyme
Reactant
NONE OF THESE
Reactant
Enzymes increase the rate of a given reaction by lowering what kind of energy:
Combination
Activation
Thermal
Electrical
Solar
Activation
Which of the following may show enzymatic activity?
Lipids
Proteins
DNA
Lipids and proteins
Proteins and carbohydrates
Proteins
Which of the following is NOT true of enzyme behavior?
Enzyme shape may change during catalysis.
The active sit of an enzyme orients its substrate molecules, thereby promoting interaction of their reactive parts.
All enzymes have an active site where substrates are temporarily bound.
Each enzyme can catalyze a wide variety of different reactions.
None of these
Each enzyme can catalyze a wide variety of different reactions.
Enzymes
Control speed of a reaction
Change shapes to facilitate certain reactions
May place physical stress on bonds of the substrate
May require cofactors
All of these
All of these
Enzymatic reactions can be affected by
pH
salinity
temperature
cofactors
all of these
All of these
In metabolic pathways that are regulated by feedback inhibitions, the ___ inhibits the activity of the _____
Product; first enzyme
First enzyme; product
Second enzyme; first enzyme
Last enzyme; first enzyme
Reactant' product
Product; first enzyme
Allosteric inhibition is generally a result of:
excess substrates
binding regulatory molecules at a site other than the active site
a change in temperature of the system
binding of the regulatory molecule at the active site
pH inhibition
binding regulatory molecules at a site other than the active site
The removal of electrons from a compound is known as:
dehydration
oxidation
reduction
phosphorylation
a nonreversible chemical reaction
oxidation
A ___ is an organized series of reactions steps in which membrane bound arrays of enzymes and other molecules give up and accept electrons in turn.
Cyclic metabolic pathway
Endergonic reaction
Electron transfer chain
Concentration gradient
Passive transport
Electron Transfer Chain
In a cyclic metabolic pathway,
product inhibits the first enzyme
last step regenerates an enzyme for the first step
product inhibits the last enzyme
last step regenerates a reactant for the first step
regulatory molecules bind to regions other than the active site
last step regenerates a reactant for the first step
A single celled freshwater organism, such as a protistan, is transferred into salt water. Which of the following is likely to happen?
The cell bursts
Salt is pumped out of the cell
The cell shrinks
Enzymes flow out of cell
All of these
The cell shrinks
In simple diffusion:
The rate of movement of molecules is controlled by temperature and pressure.
The movement of individual molecules is random.
The movement of molecules of one substance is independent of one substance is independent of the movement of any other substance.
The net movement is away from the region of highest concentration.
All of these
All of these
Which statement is true?
A cell placed in an isotonic solution will swell.
A cell placed in a hypotonic solution will swell.
A cell placed in a hypotonic solution will shrink.
A cell placed in a hypertonic solution will remain the same.
A cell placed in a hypertonic solution will swell.
A cell placed in a hypotonic solution will swell.
Which of the following is a passive process that requires a protein for movement of a solute across a membrane?
Active transport
Endocytosis
Bulk flow
Facilitated diffusion
None of these
Facilitated diffusion
Movement of a molecule against a concentration gradient occurs in:
Simple diffusion
Facilitated diffusion
Osmosis
Active transport
Passive transport
Active transport
The sodium potassium pump is an example of:
Active transport
Passive transport
Facilitated diffusion
Osmosis
Simple diffusion
Active transport
The carrier molecules used in active transport are:
Calcium ions in the calcium pump
Proteins
ATP molecules
Carbohydrates
lipids
proteins
Bacteriophages are:
large bacteria
pathogens
viruses
cellular components
protistans
viruses
The building blocks of nucleic acids are:
Amino acids
Fatty acids
Monosaccharides
Nucleotides
All of these
Nucleotides
Which of the following is not related to the other four?
Amino Acids
Nucelotides
5 carbon sugars
phosphate
nitrogenous bases
amino acids
In the pairing of two nucleotides within the double helix:
Hydrogen bonds are used
Adenine and thymine bind together
Purines bind with pyrimidines
Double ring nitrogenous bases connect to single ring bases
All of these occur
All of these occur
In the bonding of nitrogenous bases:
A is paired with C
A is paired with G
C is paired with T
G is paired with C
G is paired with T
G is paired with C
Which statement is true?
The hydrogen bonding of C and G is an example of complementary base pairing.
A will always pair with G in DNA, and C teams up with T.
Each of the four nucleotides in DNA have the same nitrogen containing base.
When A pairs with T, they are linked by three hydrogen bonds
In DNA of all species, the amount of purines never equals the amount of pyrimidines
The hydrogen bonding of C and G is an example of complementary base pairing.
Each DNA strand has a backbone that consists of alternating:
Pruines and pyrimidines
Nitrogen containing bases
Hydrogen bonds
Sugar and phosphate molecules
Amines and purines
Sugar and phosphate molecules
The best adjective to describe DNA replication is:
non disruptive
semiconservative
progressive
conservative
lytic
Semiconservative
Replication of DNA:
produces RNA molecules
produces only new DNA
produces 2 molecules, each of which is half new and half old DNA joined lengthwise to each other
generates excessive DNA, which eventually causes the nucleus to divide
Is too complex to characterize
produces 2 molecules, each of which is half new and half old DNA joined lengthwise to each other
DNA polymerase
is an enzyme
adds new nucleotides to a strand
proofreads DNA strands to see they are correct
makes rare mistakes resulting in mutation
is all of these
is all of these
DNA ligase:
Joins together fragments of DNA
Replaces mis-paired bases
Initiates DNA replication
Forms new DNA polymers
Is all of these
joins together fragments of DNA
The DNA molecule is usually made up of how many strands?
1
2
3
6
12
2
How many different types of RNA molecules are needed to make protein?
1
2
3
4
6
3
What is the form of RNA that carries the code from the DNA to the site where the protein is assembled?
messenger RNA
nuclear RNA
ribosomal RNA
transfer RNA
structural RNA
messenger RNA
Which of the following carries amino acids to ribosomes, where amino acids are linked into the primary structure of a polypeptide?
mRNA
tRNA
hnRNA
rRNA
all of these
tRNA
The nitrogenous base found in DNA but not RNA is:
adenine
cytosine
guanine
uracil
thymine
thymine
Which substance is found in RNA but not DNA
thymine
deoxyribose
ribose
guanine
cytosine
ribose
Uracil will pair with
adenine
cytosine
ribose
thymine
guanine
adenine
The main component of ribosome is:
DNA
protein
RNA
both DNA and RNA
phospholipid
RNA
The synthesis of an RNA molecule from a DNA template strand is called
Replication
Translation
Transcription
DNA synthesis
metabolism
transcription
The relationship between RNA and the DNA that served as a template is:
antagonistic
opposite
complementary
an exact duplicate
unrelated
Complementary
Which of the following catalyzes the process of transcription?
RNA polymerase
DNA polymerase
Ligase
Gyrase
all of these
RNA polymerase
In transcription
Several RNA molecules can be transcribed from the same DNA molecule
Promoters are needed so that RNA polymerase can bind to DNA
DNA produces messenger RNA
a specific enzyme called RNA polymerase is required
All of these occur
All of these occur
The portion of the DNA molecule that is translated is composed of
introns
anticodons
exons
transcriptons
both exons and transcriptons
exons
In transcription:
Several amino acids are assembled by the messenger RNA molecules at one time
A special sequence called a promoter is necessary for transcription to begin
Certain polypeptide sequences are governed by one ribosome, while the other sequences are produced by other ribosomes
The transfer RNA molecules arrange the messenger RNA codons into the appropriate sequence
none of these occur
A special sequence called a promoter is necessary for transcription to begin
A polysome is:
a ribosomal unit
the nuclear organelle that synthesizes rRNA
an organelle that functions during meiosis
the two ribosomal subunits together
an mRNA molecule with several ribosomes attached
an mRNA molecule with several ribosomes attached
In transcription ________ is used as a template for the construction of a new RNA molecule.
The entire DNA molecule
Both strands of a double stranded segment of DNA
A segment of one strand of double-stranded DNA
an entire RNA molecule
A single stranded segment of RNA
Segment of one strand of double-stranded DNA
The genetic code is made up of units consisting of how many nucleotides:
2
3
5
6
12
3
There are how many different kinds of amino acids in proteins?
3
6
12
20
28
20
There are how many different mRNA codons?
3
12
28
64
120
64
Which of the following is the normal start codon for protein synthesis:
AUG
UAA
UAG
UGA
none of these
AUG
The concept of a set of three nucleotides specifies a particular amino acid provides the basis for:
The one gene, one enzyme hypothesis
The one gene, one polypeptide hypothesis
The genetic code
Biochemical reactions among nucleic acids
All of these
The genetic code
Of all the different codons that exist, three of them:
are involved in mutations
do not specify a particular amino acid
cannot be copied
provide instructions such as "stop"
do not specify a particular amino acid but provide instructions like "stop"
do not specify a particular amino acid but provide instructions like "stop"
If the DNA triplets were ATG-CGT, the mRNA codons would be:
AUGCGU
ATGCGT
UACGCA
UAGCGU
none of these
UACGCA
If the DNA triplets were ATG-CGT, the tRNA anticodons would be:
AUGCGU
ATGCGT
UACGCA
UAGCGU
none of these
AUGCGU
Which of the following has an anticodon to bind to the protein synthesizing machinery?
DNA
mRNA
rRNA
tRNA
none of these
tRNA
Ribosomes function as:
A single unit
2 part
3 part
4 part
multi-divisional
2 part
The first step in translation is called:
elongation
initiation
replication
termination
translocation
initiation
Translation begins when the initiator tRNA binds to
the large ribosomal unit
the small ribosomal unit
the second tRNA
the terminator codon
none of these
the small ribosomal unit
The first amino acid in most proteins is:
Alanine
Isoleucine
Leucine
Methinonine
Phenylalanine
Methinonine
Termination of protein translation is due to:
The lack of amino acids
Wobble effects
the AUG codon
Lack of messenger RNA
a stop codon
a stop codon
A gene mutation:
is a change in the nucleotide sequence of DNA
may be caused by environmental agents
may arise spontaneously
can occur in all organisms
is all of these
is all of these
Enzymes used to cut DNA molecules in recombinant DNA research are:
ligases
restriction enzymes
transcriptases
DNA polymerases
replicases
restriction enzymes
Which of the following enzymes join the paired sticky ends of DNA fragments?
reverse transcriptase
restriction enzymes
DNA ligase
DNA polymerase
transferase
DNA ligase
Small circular molecules of DNA in bacteria are called:
plasmids
desmids
pili
F particles
transferrins
plasmids
Because it has no introns, researchers prefer to use ____ when working with human genes.
cDNA
cloned DNA
hybridized DNA
RFLPS
viral DNA
cDNA
RNA can manufacture DNA via the action of:
DNA polymerase
RNA polymerase
Reverse transcriptase
Ligase
Restriction enonuclease
Reverse transcriptase
cDNA is copied from:
DNA
mRNA
rRNA
tRNA
protein
mRNA
Probes for cloned genes use:
complementary nucleotide sequences labeled with radioactive isotopes
certain media with specific antibodies
specific enzymes
certain bacteria sensitive to the genes
all of these
complementary nucleotide sequences labeled with radioactive isotopes
A collection of cells containing DNA fragments produced by restriction enzymes and incorporated into plasmids is called:
copied DNA
transcribed DNA
DNA amplification
a DNA library
plasmid DNA
a DNA library
For the polymerase chain reaction to occur,
Isolated DNA molecules must be primed
All DNA fragments must be identical
The DNA must be separated into single strands
A sticky end must be available for the ligase enzyme to function
Isolated DNA molecules must be primed, and the DNA must be separated into single strands
Isolated DNA molecules must be primed, and the DNA must be separated into single strands
The enzyme used in the polymerase chain reaction is:
A restriction enzyme
Reverse transcriptase
DNA polymerase
RNA replicase
Ligase
DNA polymerase
The polymerase used in PCR was isolated from:
Escherichia coli
Haemophilus influenzae
Homo sapiens
Thermus aquaticus
Streptococcus pneumoniae
Thermus aquaticus
The laboratory technique used to separate the DNA fragments produced by automated DNA sequencing is:
The polymerase chain reaction
Gel electrophoresis
Ultracentrifugation
Electron microscopy
Fluorescence microscopy
Gel electrophoresis
What is the purpose of the modified bases in DNA sequencing?
DNA replication terminates when a modified base is added.
They are easily recognized by the computer.
They are added to the DNA chain just like the normal bases.
All of these.
None of these.
All of these.
E Coli that contains the genes for human insulin is:
Genetically engineered
Transgenic
a GMO
All of these
None of these
All of these
The Ti plasmid from which plant pathogen is used to transfer plant genes between species?
Agrobacterium tumefaciens
Escherechia coli
Haemophilus influenzae
Salmonella typhimurium
Streptococcus faecalis
Agrobacterium tumefaciens
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