Bio 180 Exam 4
The formation of Succinyl CoA from Succinate and CoA has a ΔG = +8.6. The formation of ATP from ADP and Pi has a ΔG = +8.2. What is the ΔG for the hydrolysis of ATP coupled to the formation of Succinyl-CoA. (Hint: write out the reaction equations for each and make sure the reactions are in the appropriate direction)
0.4
How many molecules of CO2 are formed by 5 turns of the citric acic cycle
10
Substrate-level phosphorylation accounts for approximately what percentage of the ATP formed during glycolysis?
100%
For each molecule of glucose that is metabolized by glycolysis and the citric acid cycle, what is the total number of NADH + FADH2 molecules produced?
12
How many total ATP are produced from 3 glucose molecules through the various glycolytic pathways?
12
How many ribulose bisphosphates must be fixed with CO2 to sustainably remove a single glyceraldehyde-3-phosphate from the Calvin cycle for the synthesis of glucose?
3
Starting with citrate, which of the following combinations of products would result from three turns of the citric acid cycle?
3 ATP, 6 CO2, 9 NADH, and 3 FADH2
How many NADPH molecules are required to generate 3 molecules of glucose?
36
The jellyfish Aequorea Victoria contains a fluorescent protein that is optimally excited by 488nm wavelength light (a blue-green color). Based on your understanding of the second law of thermodynamics, which of the following describe the light emitted by this protein following excitation?
A green color with a wavelength above 488nm
If a photon of violet light is absorbed by a solution of chlorophyll (no photosystem). How is that absorbed energy eventually released?
A new photon of red light is emitted
How does pyruvate enter the matrix of the mitochondrion?
Active transport
The process by which simple molecules are assembled into more complex nutrients with the input of energy is called?
Anabolism
Pyruvate oxidation (to acetyl-CoA) cannot happen in the absence of oxygen. Which statement best describes the dependence of pyruvate oxidation on oxygen?
As the terminal electron acceptor, oxygen is required for the recycling of NADH back to NAD+
You are motor biking on the St Anthony sand dunes when you run across a previously unknown plant species. You bring a sample to the lab to study its regulation of photosynthesis. You inject radioactive malate into the leaf and find that there is a loss of malate during daytime when temperatures are high but there is no loss of malate during the cooler nighttime temperatures. From this data you surmise that your plant is a new variety that uses the
CAM
Which of the following is an example of an Anabolic process
Calvin cycle
Caproic acid is a 6-carbon fatty acid (C6H12O2). When compared to glucose (C6H12O6), which molecule would generate the greatest amount of ATP production following the complete metabolism of each molecule
Caproic acid
Caproic acid is a 6-carbon fatty acid (C6H12O2). When compared to glucose (C6H12O6), which molecule would yield a higher number of carbon dioxide molecules following its complete metabolism?
Carbon Dioxide production will be the same for both molecules
The process by which nutrients are degraded to salvage their components and or generate energy is called?
Catabolism
The cytochrome b-f protein in photosynthesis is analogous to ___________ in cell respiration?
Complex III
Which of the following terms is NOT associated with Photosystem II
Cyclic electron flow
Which of the following produces ATP?
Cyclic electron flow Non cyclic electron flow
In step 2 of glycolysis there is an isomerization from glucose 6 phosphate to fructose-6-phosphate. The bond types that are broken and then reformed are the same making delta G for the reaction is very close to zero. How is it if delta G is zero that there is a net movement of substrate to product?
Delta G is made negative by increasing the concentration of glucose-6-phosphate
Which of the following most accurately describes how a chloroplast regulates the shift from non-cyclic to cyclic electron flow
Excess NADPH in the stroma will shift the ΔG of the reaction catalyzed by NADP reductase making the reaction non-spontaneous, in which case ferrodoxin will instead deliver electrons to the electron transport chain leading to more ATP production.
Which of the following describes the sequence of electron carriers in the electron transport chain, starting with the least electronegative?
FMN, Fe•S, ubiquinone, cytochromes (Cyt)
T/F An Open system can exchange matter but not energy
False
Adenosine triphosphate is often cited as the energy currency of the cell. Which of the following molecules would theoretically have the same energy transfer capacity as ATP? (mark all that apply)
GTP UTP
Larger more complex molecules like glucose have more potential energy than smaller less complex molecules like carbon dioxide because
Glucose has more chemical bonds than carbon dioxide
Which of the following is an example of an Catabolic process
Glycolysis Krebs cycle Protein digestion Beta oxidation
When 1 mole of ATP is hydrolyzed in a test tube without an enzyme, about twice as much heat is given off as when 1 mole of ATP is hydrolyzed in a cell. Which of the following best explains these observations?
In the cell, the hydrolysis of ATP is coupled to other endergonic reactions
The free energy for the oxidation of glucose to CO2 and water is -686 kcal/mole and the free energy for the reduction of NAD+ to NADH is +53 kcal/mole. Why are only two molecules of NADH formed during glycolysis when it appears that as many as a dozen could be formed?
Most of the free energy available from the oxidation of glucose remains in pyruvate, one of the products of glycolysis.
Which of the following best describes the roles of NADH and NADPH?
NADH is used in catabolic pathways and NADPH is used in anabolic pathways
Which of the following stages requires oxygen as reactant?
None: Reductions stage Ribulose regeneration stage Fixation stage
The ATP produced in the chloroplast stomata is
Only used in the Calvin cycle
When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?
PH increases
On a hot day, a plant will close its stomata in order to
Prevent loss of water
Temperature can affect enzyme catalyzed reactions in the following ways
Raising the temperature will eventually denature an enzyme rendering it nonfunctional Changing the temperature will make it more or less likely for a reaction to overcome the energy of activation. Changing the temperature can change the ΔG of a reaction, making it more or less spontaneous
Electrons will only travel through the electron transport chain in one direction. For example, from complex three to cytochrome c and not vice versa. Which of the following terms can be used to best explain this phenomenon
Reduction Potential
Succinate dehydrogenase catalyzes the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid. Based on this information, which of the following is correct?
Succinate is the substrate, and fumarate is the product
Molecule A has a total of 15 covalent bonds and is stored at a temperature of 15 degrees Celsius in system A. Molecule B has a total of 5 covalent bonds and is stored at a temperature of 45 degrees Celsius in system B. Assume there are 100 molecules of each in their respective systems. Which system contains more potential energy?
System A because it has more covalent bonds
Molecule A has a total of 15 covalent bonds and is stored at a temperature of 15 degrees Celsius in system A. Molecule B has a total of 5 covalent bonds and is stored at a temperature of 45 degrees Celsius in system B. Assume there are 100 molecules of each in their respective systems. Which system contains more Kinetic energy?
System B because it has a higher temperature
The process of oxidative phosphorylation can be likened to a battery that powers a water pump as well as a turbine which is powered by the pumped water.
The force of the movement of the pumped water down through a turbine
The process of oxidative phosphorylation can be likened to a battery that powers a water pump as well as a turbine which is powered by the pumped water.
The force of the movement of the pumped water down through a turbine.
When 10,000 molecules of ATP are hydrolyzed to ADP and Pi in a test tube, about twice as much heat is liberated as when the same amount of ATP is hydrolyzed in a cell . Which of the following is the best explanation for this observation?
The hydrolysis of ATP in a cell produces different chemical intermediates than does the reaction in a test tube.
Which statement best describes the primary purpose of fermentation?
The oxidation of NADH
ATP has three different structural regions. Which of the following regions is primarily responsible for the energy transfers that ATP carries out in the cell?
The poly phosphate
The reaction centers in Photosystem I and II get their names from the wavelength of light that is optimally needed to excite their electrons. Which of the following statements is true then about these excitation wavelengths?
They have a lower energy level than most wavelengths of visible light
If a reaction has a +ΔG then the reverse reaction will have a -ΔG.
True
T/F If you double the amount of reactant in a chemical reaction then you will at least double the ΔG of the reaction
True
The earth can receive energy and release energy but does not significantly exchange matter. This makes the earth a closed system
True
Zinc, an essential trace element for most organisms, is present in the active site of the enzyme carboxypeptidase. The zinc most likely functions as a(n)
cofactor necessary for enzyme activity
The active site of an enzyme is the region that
is involved in the catalytic reaction of the enzyme
Which of the following is true regarding the purposes of breathing?
o provide oxygen as a terminal electron acceptor
In linear electron flow reduced plastocyanin passes on its electrons to
p700+
An electron loses potential energy when it
shifts to a more electronegative atom.
Carbon skeletons for amino acid biosynthesis are supplied by intermediates of the citric acid cycle. Which intermediate would supply the carbon skeleton for synthesis of a five-carbon amino acid?
α -Ketoglutarate
The mathematical expression for the change in free energy of a system is △G =△H-T△S. Which of the following is (are) correct?
△G is the change in free energy.
