Which of the following is an example of potential energy rather than
kinetic energy? A) the muscle contractions of a person mowing
grass B) water rushing over Niagara Falls C) light flashes
emitted by a firefly D) a molecule of glucose E) the
flight of an insect foraging for food
D) A molecule of glucose
Which of the following is (are) true for anabolic pathways? A)
They do not depend on enzymes. B) They are usually highly
spontaneous chemical reactions.C) They consume energy to build
up polymers from monomers. D) They release energy as they
degrade polymers to monomers. E) They consume energy to decrease
the entropy of the organism and its environment.
C) They consume energy to build up polymers from monomers
Which of the following is true for all exergonic reactions? A)
The products have more total energy than the reactants.B) The
reaction proceeds with a net release of free energy. C) The
reaction goes only in a forward direction: all reactants will be
converted to products, but no products will be converted to reactants.
D) A net input of energy from the surroundings is required for
the reactions to proceed. E) The reactions are rapid.
B) The reaction proceeds with a net release of free energy
When chemical, transport, or mechanical work is done by an organism,
what happens to the heat generated? A) It is used to power yet
more cellular work. B) It is used to store energy as more ATP.
C) It is used to generate ADP from nucleotide precursors.
D) It is lost to the environment. E) It is transported to
specific organs such as the brain.
D) It is lost to the environment
According to the induced fit hypothesis of enzyme catalysis, which of
the following is correct? A) The binding of the substrate
depends on the shape of the active site. B) Some enzymes change
their structure when activators bind to the enzyme. C) A
competitive inhibitor can outcompete the substrate for the active
site. D) The binding of the substrate changes the shape of the
enzyme's active site. E) The active site creates a
microenvironment ideal for the reaction.
D) The binding of the substrate changes the shape of the enzyme's
active site
When you have a severe fever, what grave consequence may occur if the
fever is not controlled? A) destruction of your enzymes' primary
structure B) removal of amine groups from your proteins C)
change in the tertiary structure of your enzymes D) removal of
the amino acids in active sites of your enzymes E) binding of
your enzymes to inappropriate substrates
C) Change in the tertiary structure of your enzyms
The mechanism in which the end product of a metabolic pathway
inhibits an earlier step in the pathway is most precisely described as
A) metabolic inhibition. B) feedback inhibition. C)
allosteric inhibition. D) noncooperative inhibition. E)
reversible inhibition.
B) Feedback Inhibition
Which of the following statements regarding enzymes is true? A)
Enzymes increase the rate of a reaction by making the reaction more
exergonic. B) Enzymes increase the rate of a reaction by
lowering the activation energy barrier. C) Enzymes increase the
rate of a reaction by reducing the rate of reverse reactions. D)
Enzymes change the equilibrium point of the reactions they catalyze.
E) Enzymes make the rate of a reaction independent of substrate concentrations.
B) Enzyme increase the rate of a reaction by lowering the activation
energy barrier
Which curve on the graph above may represent the temperature and pH
profiles of enzymes taken from a bacterium that lives in a mildly
alkaline hot spring at a temperature of 70 (degrees) or higher?
- Curves 3 & 5
The following question is based on the reaction, A + B ? C + D shown
in figure 8.1. Which of the following represents the activation energy
required for enzyme catalyze reaction?
B - (which represents the activation energy)
Some bacteria are metabolically active in hot springs becauseA)
they are able to maintain a lower internal temperature.B) high
temperatures make catalysis unnecessary.C) their enzymes have
high optimal temperatures.D) their enzymes are completely
insensitive to temperature.E) they use molecules other than
proteins or RNAs as their main catalysts.3
C) Their enzymes have high optimal temperatures
Why are bacteria�s able to survive in high temperatures?
Because their proteins can survive or resist denaturation
Which of the following statements describes the results of this
reaction?C6H12O6+6O2-> 6CO2+6H2O+energy A. C6H12O6 is
oxidized and O2 is reducedB. O2 is oxidized and H2O is
reducedC. CO2 is reduced and O2 is oxidized D. C6H12O6 is
reduced and CO2 is oxidized E. O2 is reduced and CO2 is oxidized
A) C6H12O6 us oxidized and O2 is reduced
During aerobic respiration, electrons travel downhill in which sequence?
A) food (glucose) ? NADH ? electron transport chain ? oxygen
B) glucose ? pyruvate ? ATP ? oxygen
C) glucose ? ATP ? electron transport chain ? NADH
D) food ? glycolysis ? citric acid cycle ? NADH ? ATP
A) food? NADH ? electron transport chain ? oxygen
The ATP made during glycolysis is generated from the substrates that
is in the cytoplasm before phosphorylation is called..A.
photophosphorylation.B. oxidation of NADH to NAD+.C.
substrate-level phosphorylation.D. electron transport.E. chemiosmosis.
C) Substrate-level phosphorylation
Which process in eukaryotic cells will proceed normally whether
oxygen (O?) is present or absent? A) electron transport B)
glycolysis C) the citric acid cycle D) oxidative
phosphorylation E) chemiosmosis
B) glycolysis
The final electron acceptor of the electron transport chain that
functions in aerobic oxidative phosphorylation isA.
pyruvate.B. ADP.C. oxygen.D. NAD+.E. water.
C) oxygen
Where are the proteins of the electron transport chain
located?A. mitochondrial outer membraneB. mitochondrial
inner membraneC. mitochondrial matrixD. cytosolE.
mitochondrial intermembrane space
B) mitochondrial inner membrane
What is the oxidizing agent of the following reaction: NADH is
getting reduced?
Pyruvate
How many Carbon dioxide molecule are released during cellular
respiration as a result of oxidation of one molecule of glucose?
Six
Why are carbohydrates and fats considered high energy foods? A)
They have a lot of oxygen atoms. B) They have no nitrogen in
their makeup. C) They can have very long carbon skeletons.
D) They have a lot of electrons associated with hydrogen.
E) They are easily reduced.
D) They have a lot of electrons associated with hydrogen
Which of the following intermediary metabolize enters the citric acid
cycle and is formed in part by the removal of a carbon dioxide from
one molecule of pyruvate?
Acetyl-co A
Which of the following is characterized by a cell releasing a signal
molecule into the environment, followed by a number of cells in the
immediate vicinity responding?A. endocrine signalingB.
synaptic signalingC. autocrine signalingD. hormonal
signalingE. paracrine signaling
E) Paracrine Signaling
Testosterone functions inside a cell byA. acting as a signal
receptor that activates tyrosine kinases.B. coordinating a
phosphorylation cascade that increases spermatogenesis.C. acting
as a steroid signal receptor that activates ion channel
proteins.D. binding with a receptor protein that enters the
nucleus and activates specific genes.E. becoming a second
messenger that inhibits nitric oxide.
D) binding with a receptor protein that enters the nucleus and
activates specific genes
Which of the following is true of transcription factors?A. They
initiate the epinephrine response in animal cells.B. They
transcribe ATP into cAMP.C. They regulate the synthesis of
lipids in the cytoplasm.D. They control gene expression.E.
They regulate the synthesis of DNA in response to a signal.
D) They control gene expression
In the formation of biofilms, such as those forming on unbrushed
teeth, cell signaling serves which function?A. digestion of
unwanted parasite populationsB. aggregation of bacteria that can
cause cavitiesC. secretion of substances that inhibit foreign
bacteriaD. secretion of apoptotic signalsE. formation of
mating complexes
B) Aggregation of bacteria that can cause cavities
Which of the following statements about quorum sensing is FALSE?
Quorum sensing _____. A) is cell-cell communication in
eukaryotesB) is species specificC) may result in biofilm
formationD) is particularly well studied because of its medical importance
A) is cell-cell communication in eukaryotes
What is a genome?A) The complete complement of an organism's
genesB) A specific set of polypeptides within each cellC)
A specialized polymer of four different kinds of monomersD) A
specific segment of DNA that is found within a prokaryotic
chromosomeE) An ordered display of chromosomes arranged from
largest to smallest
A) the complete complement of an organism's genes
In general, a signal transmitted via phosphorylation of a series of
proteins A) brings a conformational change to each protein.
B) requires binding of a hormone to a cytosol receptor. C)
cannot occur in yeasts because they lack protein phosphatases.
D) requires phosphorylase activity. E) allows target cells
to change their shape and therefore their activity.
A) Brings a conformational change to each protein
Which of the following describes the events of apoptosis?A. The
cell's DNA and organelles become fragmented, the cell dies, and it is
phagocytized.B. The cell dies, and the presence of its
fragmented contents stimulates nearby cells to divide.C. The
cell's DNA and organelles become fragmented, the cell shrinks and
forms blebs, and the cell's parts are packaged in vesicles that are
digested by specialized cells.D. The cell's nucleus and
organelles are lysed, and the cell enlarges and bursts.E. The
cell dies, it is lysed, its organelles are phagocytized, and its
contents are recycled.
C) The cell's DNA and organelles become fragmented, the cell shrinks
and forms blebs, and the cell's parts are packaged in vesicles that
are digested by specialized cells.
The centromere is a region in which A) chromatids remain
attached to one another until anaphase. B) metaphase chromosomes
become aligned at the metaphase plate. C) chromosomes are
grouped during telophase. D) the nucleus is located prior to
mitosis. E) new spindle microtubules form at either end.
A) Chromatids remain attached to one another until anaphase
If cells in the process of dividing are subjected to colchicine, a
drug that interferes with the formation of the spindle apparatus, at
which stage will mitosis be arrested?A) anaphaseB)
prophaseC) telophaseD) metaphaseE) interphase
D) metaphase
Regarding mitosis and cytokinesis, one difference between higher
plants and animals is that in plants
A cell plate begins to form at telophase, whereas in animals a
cleavage furrow is initiated in that stage
During which phase of mitosis do the chromatids become chromosomes?
Telophase
Which of the following is true concerning cancer cells? A) They
do not exhibit density-dependent inhibition when growing in culture.
B) When they stop dividing, they do so at random points in the
cell cycle. C) They are not subject to cell cycle controls.
D) When they stop dividing, they do so at random points in the
cell cycle, and they are not subject to cell cycle controls. E)
When they stop dividing, they do so at random points in the cell
cycle; they are not subject to cell cycle controls; and they do not
exhibit density-dependent inhibition when growing in culture.
E) When they stop dividing, they do so at random points in the cell
cycle; they are not subject to cell cycle controls; and they do not
exhibit density-dependent inhibition when growing in culture.
After telophase I of meiosis, the chromosomal makeup of each daughter
cell is A) diploid, and the chromosomes are each composed of a
single chromatid. B) diploid, and the chromosomes are each
composed of two chromatids. C) haploid, and the chromosomes are
each composed of a single chromatid. D) haploid, and the
chromosomes are each composed of two chromatids. E) tetraploid,
and the chromosomes are each composed of two chromatids.
D) haploid, and the chromosomes are each composed of two chromatids
The human X and Y chromosomesA) are both present in every
somatic cell of males and females alike.B) are of approximately
equal size and number of genes.C) are almost entirely
homologous, despite their different names.D) include genes that
determine an individual's sex.E) include only genes that govern
sex determination
D) include genes that determines an individual's sex
Which of the following occurs in meiosis but not in mitosisa.
chromosome replicationb. synapsisc. production of daughter
cellsd. alignment of tetrads at metaphase platee. both B
and D
E) both B and D
If the liver cells of an animal have 24 chromosomes, how many
chromosomes do its sperm cells have? A) 6 B) 12 C)
24 D) 48 E) 64
B) 12
Which of the following is true of the process of meiosis?
four haploid cells is a result
What explains the increased concentration of Ca++ in the
ERA)calcium ions are actively imported from the cytoplasm into
the ERB)calcium concentration is kept low in the cytoplasm
because of its high usage levelC)calcium cannot enter the plasma
membrane through ion channelsD)calcium levels in the blood or
other body fluids are extremely lowE)the Ca ions are recycled
from other molecules in the ER
A) Calcium ions are actively imported from the cytoplasm into the ER
Lipid-soluble signaling molecules, such as testosterone, cross the
membranes of all cells but affect only target cells becausea.
only target cells retain the appropriate DNA segmentsb.
intracellular receptors are present only target cellsc. most
cells lack the Y chromosome requiredd. only target cells possess
the cytosolic enzymes that transduce the testosteronee. only in
target cells is testosterone able to initiate the phosphorylation
cascade leading to activated transcription factor
B) Intracellular receptors are present only in target cells