Quiz 3 (Ch 6, 7, 8)
Summer II 2008
Name: _______________________
July 24th
1) Which of these processes occurs in the cytosol?
a)
b)
c)
d)
e)
the citric acid cycle
glycolysis
the electron transport system
the transition reaction
the preparatory reaction
2) Why WOULDN’T pyruvate enter the mitochondria for further energy extraction?
a)
b)
c)
d)
e)
Because it is oxidized by NADH in the presence of oxygen.
Because there is no oxygen.
Because pyruvate can’t cross a lipid bilayer.
Because there is not enough chemiosmotic pressure to make ATP
Because it is rapidly broken down to lactic acid.
3) Some bacteria are strict aerobes and others are strict anaerobes. Some bacteria, however, are facultative anaerobes and can
live with or without oxygen. If given the choice of using oxygen or not, which should a facultative anaerobe perform?
a) Use oxygen since aerobic metabolism provides more ATP per molecule of carbohydrate broken down than anaerobic
metabolism.
b) Not use oxygen since it is a facultative anaerobe, it doesn't tolerate oxygen well.
c) Use oxygen because aerobic metabolism is easier.
d) Not use oxygen because this will hamper the electron transport chain.
e) It doesn't matter; both process will produce the same results.
4) The first reaction in the citric acid cycle is binding
a)
b)
c)
d)
e)
carbon dioxide to a four-carbon (C4) molecule.
carbon dioxide to a five-carbon (C5) molecule.
acetyl-CoA to a C4 molecule.
acetyl-CoA to a C5 molecule.
none of these are true.
5) Endergonic reactions…
a)
b)
c)
d)
e)
are always coupling reactions.
have a negative ΔG and occur spontaneously.
can only occur if there is an input of energy.
have products with less free energy than the reactants.
All of the choices are correct.
6) Which statement BEST describes the second law of thermodynamics?
a)
b)
c)
d)
e)
Energy is neither created nor destroyed, but can change into matter.
Energy is neither created nor destroyed, but it can change from one energy form to another.
Energy can be created from matter or used to produce matter.
Some useful energy is lost as heat whenever an energy transfer occurs.
Energy transfers are always 100% efficient in changing energy from one useful form to another.
7) If enzymes could not be used during a reaction, which of the following could be added to a system to increase the reaction
rate?
a) substrate
b) energy in the form of heat
c) product
d) water
e) ATP or some other coenyzme
8) If there are twelve different intermediate products produced in the stages for production of an organic compound in a cell, we
can expect that there
a) is a single enzyme carrying this process through to the end product.
b) is a single enzyme for degradation and another enzyme for synthesis.
c) are about twelve enzymes, at least one responsible for each step in the metabolic pathwaymay not be any enzymes
involved if this is a natural cell product.
d) must be twelve different raw materials combined in the cell by one enzyme.
e) none of the above.
9) One molecule donates an electron to another molecule. The electron donor molecule is…
a)
b)
c)
d)
e)
f)
reduced.
transformed.
oxidized.
inhibited.
an anion
an Onion
10) What establishes the electrochemical gradient across a membrane to provide energy for ATP production?
a)
b)
c)
d)
e)
The chloroplast's electron transport system provides the ions.
Hydrogen ions naturally collect on the outside of the organelle membrane.
Hydrogen ions are pumped across the membrane by carrier proteins.
Photosystem II sends a high-energy electron down an energy gradient.
All of the choices work to establish the electrochemical gradient.
11) If plants could only undergo the cyclic electron pathway during photosynthesis in a C3 plant, which of the following would be
TRUE?
a)
b)
c)
d)
e)
Plants would not produce oxygen.
Carbohydrate could still be produced but in much smaller quantities.
Little or no NADPH would be produced.
ATP production would decrease due to a smaller amount of H+ being available.
The rate of the Calvin cycle would be increased.
12) When an electron has been excited to a higher energy state, it can then drop back to the original level, re-emitting the light as
fluorescence. When chlorophyll is extracted in solution, and a bright red or blue light is shown on it, the chlorophyll fluoresces
brightly. However, when the chlorophyll is packaged inside chloroplasts and the red or blue light is turned on, there is no
fluorescence. This most likely indicates that
a)
b)
c)
d)
e)
the red and blue light waves are reflected by the chlorophyll membrane.
chlorophyll in solution has a different 3D structure than chlorophyll in a chloroplast.
excited electrons are transferred to electron acceptors in the chloroplast.
fluorescence does not work in living cells.
green light must be used to make living cells fluoresce.
13) What is the difference between a single proton within the thylakoid space and one in the stroma?
a)
b)
c)
d)
e)
Protons in the thylakoid space are extracted from water; those in the stroma are not.
Protons in the stroma are extracted from water; those in the thylakoid space are not.
There is no difference between these two protons.
Protons in the stroma have more potential energy in the form of REDOX potential than those in this thylakoid space.
Protons in the thylakoid space are more acidic than those in the stroma.
14) The correct operational sequence of the three processes listed below is
I. Glycolysis
II. ETC
III. Krebs cycle
a)
b)
c)
d)
e)
I
II
II
II
I





II  III
I  III
I  II
III  I
III  II