SBIOAC BIOLOGY CELLULAR RESPIRATION
Name: . 2003 02 13
Read
questions carefully. Value follows question in parentheses. Answer all
questions, as no marks will be deducted for incorrect responses. There is only
ONE correct answer for each multiple choice.
Each question is worth one mark unless otherwise noted.
TOTAL = 53 + 3 bonus
1. In diffusion,
a.
molecules move
faster in a liquid than in a gas
b.
molecules move from a region of higher
concentration to an area of lower concentration
c.
molecules move from a region of lower concentration to
an area of higher concentration
d.
molecules move faster because energy is added to the
system
2. If the volume of a cell increases when it is placed in
an aqueous solution, that solution is said to be __________ to the cell.
a. hypotonic
b. isotonic
c. hypertonic
d. gin
and tonic
3. Some
liver cells ingest bacteria, a function probably accomplished by . . .
a. phagocytosis.
b. pinocytosis.
c. exocytosis.
d. passive transport.
4. The concentration of
potassium in a red blood cell is much greater than in the surrounding plasma,
but potassium continues to move into the cell. This is an example of .
a.
osmosis
b.
diffusion
c.
facilitated diffusion
d.
active transport
5. Active transport . . .
a. moves substances down
their concentration gradient.
b. moves small uncharged
molecules through the lipid bilayer.
c. requires ATP
energy.
d. is important in
facilitated diffusion.
6. The sodium-potassium pump moves
a.
Na + and K+ into the cell
b.
Na + and K+ out of the cell
c.
Na + into the cell and K+ out
of the cell
d. Na +
out of the cell and K+
into the cell
7. Enzymes
can . . .
a. decrease the initial energy requirement of reactions.
b. make endergonic reactions exergonic.
c. change the equilibrium point of a reaction.
d. change the net energy yield of a reaction.
8. Which of the following would
bind to the active site of an enzyme?
a.
allosteric inhibitor
b.
allosteric activator
c.
competitive
inhibitor
d.
non-competitive inhibitor
9. A cuboidal (cube-shaped) cell fits across a medium-power
field of view 15 times. The diameter of
the field of view at this power is 1.8 mm.
A drawing of this cell (in proportion) measures 27 mm per edge. Give
the proper units with your answer. (2)
a. What is
the actual size of the cell? (1.8mm /15) = 0.12 mm or 120 micrometers
b. What is
the magnification of the drawing? drawing size/actual size = 27mm/0.12 mm = 225X (NO UNITS!)
10. State clearly and completely the First and Second Laws
of Thermodynamics .
(2)
The first law states that energy can be
neither created nor destroyed, only transferred or transformed. The
second law states that with every transfer or transformation of energy the
entropy (disorder/randomness) of the universe increases.
11. In an organism, free energy
a. can be obtained at no cost to the
system.
b. can be spent with no cost to the
universe.
c. is equivalent to the system’s total
energy.
d. is available to do
work.
12. Energy of activation can be
defined as the .
a.
conversion of energy in a system
b.
the amount of randomness in a
system
c.
the input of
energy needed to start a reaction
d.
the free energy change in a
system
13. A reaction
is designated as exergonic rather than endergonic when ___________.
a. no kinetic energy is released
b. the energy of the products is less than the energy of the
reactants
c. activation energy exceeds net
energy release
d. activation energy is necessary
14. To __________ a compound means to __________; in biology, this usually
results in a compound that has __________ bond energy than before the process began.
a.
reduce ... add electrons to it ... more
b. oxidize ... add electrons to it ...
less
c. reduce ... add electrons to it ...
less
d. oxidize ... take electrons from it
... more
15. Endergonic reactions, if left to
themselves, will attain equilibrium with almost none of the reactants converted
to products. But cells can make endergonic reactions go almost to completion by
____________.
a. rapidly taking up their excess
electrons
b. coupling them to the hydrolysis of ATP
c. coupling them to the formation of
ATP
d. using allosteric
enzymes to speed them up
16. An electron carrier acts as an energy storage molecule when it is
__________ (for example, __________).
a. oxidized ... NADH
b. reduced ... NAD+
c. reduced ... NADH
d. oxidized ... NAD+
17. When
glucose is completely broken down to carbon dioxide and water during aerobic respiration,
more than 50 percent of its energy is released as .
a.
ATP
b.
ADP
c.
carbon dioxide
d. heat
18. Of
the metabolic pathways listed below, the only pathway found in all organisms is .
a. fermentation.
b. electron transport chain.
c. glycolysis.
d. cellular respiration.
19. The
primary function of fermentation is to .
a.
regenerate NAD+
b.
provide alcohol to students
c.
produce NADH
d.
oxidize pyruvate
20. ATP is important because it . . . .
a. carries the genetic
information.
b. contributes entropy to the cell.
c. is one of the building blocks of DNA.
d. carries
energy from one chemical reaction to another.
e. both c and d (ATP is a ribonucleotide not a deoxyribonucleotide)
21. Substrate-level
phosphorylation requires .
a.
an enzyme, a phosphorylated intermediate and ADP
b.
an energy source and protons
c.
an enzyme, ADP and phosphate
d.
oxygen, electron transfer chain
and protons
22. Which statement best describes oxidative phosphorylation?
a.
H+ ions diffuse through the
inner membrane to make ATP
b.
H+ ions are actively transported
out of mitochondrion to make ATP in cytoplasm
c.
H+ ions accumulate in the matrix
and are used to make ATP in the Krebs cycle
d.
ATP is made in the
matrix when H+ ions diffuse through a membrane enzyme
(
and that membrane enzyme is
ATP synthase)
23. Energy
released by the breakdown of ATP can be used for
a. protein synthesis
b. muscle contraction
c. active transport of molecules
across membranes
d. all of the above
24. When pyruvate is converted to acetyl CoA ___________.
a. CO2 and Coenzyme A are formed
b. CO2 and NADH are formed
c. CO2 and ATP are formed
d. NAD+ is regenerated
25. OMIT THIS QUESTION
26. The Krebs cycle (citric
acid cycle) takes place in the
.
a. cytoplasm.
b. nucleus.
c. mitochondrion.
d. Golgi complex.
27. At the end of the Krebs
cycle, glucose is completely broken down into
.
a. oxygen and
carbon dioxide.
b. oxygen and
water.
c.
carbon
dioxide and water.
d.
oxygen, carbon
dioxide, and water.
28. Muscle tissues make lactate from pyruvate in order to . . .
a. enable you to get drunk.
b. utilize the energy in pyruvate.
c. regenerate (oxidized) NAD.
d. get rid of toxic pyruvate.
29. Suppose a molecule of
glucose is fermented by a cell. One of the end products is CH3CH2OH. Without
even knowing the name of this product, how do you know that energy could still
be extracted from it?
a. It is phosphorylated and thus energy rich.
b.
The product contains C-H bonds from which energy can be harvested.
c. The
product can be converted back to glucose.
d. It is
water-soluble.
30. If we did not breathe in O2,
we would not . . .
a. be affected because we can
switch to alcoholic fermentation.
b. make enough
ATP to sustain life.
c. have enough enzymes to
catalyze reactions.
d. be able to perform lactate
fermentation.
31. During respiration in a
eukaryotic cell, reactions of the Krebs cycle occur or are located in or on
___________.
a. across the inner membrane
of the mitochondrion
b. the cristae of the
mitochondrion
c. the cytosol
d. the matrix
of the mitochondrion
32. Which part of the cellular
catabolism of glucose requires molecular oxygen (O2)?
a. Fermentation
b. Glycolysis
c. Krebs cycle
d. The electron transport chain
33. In respiration, which one
of the following does the electron transport chain (or its components) NOT do
directly?
a.
Carry electrons
b. Phosphorylate ADP to make ATP
c.
Regenerate (oxidized) FAD
d.
Form a proton gradient
34.
Cytoplasmic NAD+ is recycled in aerobic respiration at which stage?
a. the
conversion of pyruvate to Acetyl CoA
b the
splitting of the 6-carbon sugar into two molecules of 3-carbon sugar
c. the
reduction of pyruvate
d. the transfer of electrons from cytoplasmic NADH through a shuttle to the mitochondrial
electron transport chain.
35. The final electron acceptor of the electron transport chain is .
a.
oxygen
b.
water
c.
NAD+
d. glucose
36. During oxidative
phosphorylation in eukaryotic cells, ATP-synthase catalyzes the
phosphorylation of ADP to form ATP. The
energy needed for this endergonic reaction comes from
. . .
a. the movement of
hydrogen ions from the intermembrane
space to the mitochondrial matrix.
b. the reduction of NAD+ to form NADH.
c. the movement of FADH from the cytoplasm to the mitochondria.
d. the fermentation of pyruvate to form lactic acid.
37. The efficiency of aerobic respiration is
approximately . . .
a. 10%
b. 20%
c. 2%
d. 40%
38. How many ATPs are produced by
substrate-level phosphorylation from the complete breakdown of a single molecule
of glucose in the presence of oxygen?
a. 6 ATP
b. 2 ATP
c. 36 ATP
d. 4 ATP
(2 from glycolysis, 2 from the Krebs cycle)
39. A waste product of aerobic respiration and of
alcoholic fermentation is . . .
a. carbon dioxide (CO2).
b.
NAD+
c.
ATP
d. oxygen gas (O2).
40. The major energy accomplishment of the Krebs cycle
is ___________.
a. formation of NADH
and FADH2
b. formation of ATP
c. formation of CO2
d. completion of substrate phosphorylation
41. Write the balanced CHEMICAL equation for aerobic
respiration (2).
C6H12O6 + 6O2 ®
6CO2 + 6H2O (+ energy)
42. Showing each stage in aerobic respiration, account for
each ATP generated from the complete oxidation of glucose. Also, indicate which type of phosphorylation
(do not abbreviate unless you give a
legend) has occurred and in which organelle or location within the cell the
process has occurred. Assume the maximum
number of ATP molecules per glucose is 36. (5)
SLP = substrate-level
phosphorylation
OP = oxidative phosphorylation
Cytoplasm (glycolysis) 2 ATP (SLP)
2
NADH 4 ATP (OP)
Mitochondrion (conversion to Acetyl CoA)
2
NADH 6 ATP (OP)
(Krebs
cycle)
2 ATP (SLP)
6 NADH 18 ATP
(OP)
2FADH2 4 ATP (OP)
Total = 36 ATP