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BIOL- MB Exam 3
Question | Answer |
---|---|
Where is ATP synthase located in the mitochondrion? | Inner Membrane |
The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation is... | The difference in H+ concentrations on opposite sides of the inner mitochondrial membrane |
Energy released by the electron transport chain is used to pump H+ ions into which location? | Mitochondrial intermembrane space |
The primary role of oxygen in cellular respiration is to | Act as an acceptor for electrons and hydrogen, forming water |
Where are the proteins of the electron transport chain located? | Mitochondrial Inner Membrane |
Carbon dioxide (CO2) is released during which of the following stages of cellular respiration? | Oxidation of pyruvate to acetyl CoA and the citric acid cycle |
According to the Citric Acid Cycle, how many molecules of carbon dioxide (CO2)would be produced by five turns of the citric acid cycle? | 10 |
Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of carbon (CO2) from one molecule of pyruvate? | Acetyl CoA |
In addition to ATP, what are the end products of glycolysis? | NADH and pyruvate |
The oxygen consumed during cellular respiration is involved directly in which process or event? | Accepting electrons at the end of the electron transport chain |
Where does glycolysis take place? | Cytosol |
Which of the following statements describes the results of this reaction? C6H12O6+6O2-->6CO2+6H2O+Energy | C6H12O6 is oxidized and O2 is reduced |
Match each product of pyruvate metabolism (lactate, ethanol, acetyl CoA) with the condition under which it is produced (Aerobic Oxidation, Fermentation in human muscle, fermentation in yeast and bacteria) | Lactate- fermentation in human muscle Ethanol- fermentation in yeast and bacteria Acetyl CoA- Aerobic oxidation |
Sort the following items (NAD+, lactate, NADH, pyruvate) according to whether they are reactants or products in the anaerobic reduction of pyruvate during lactic acid fermentation. | Reactants- Pyruvate + NADH Products- Lactate + NAD+ |
For each glucose that enter glycolysis, ___ acetyl CoA enter the citric acid cycle | 2 |
For each glucose that enters glycolysis, ___ NADH + H+ are produced by the citric acid cycle | 6 |
In cellular respiration, most ATP molecules are produced by ___. | Oxidative phosphorylation |
The final electron acceptor of cellular respiration is ___. | Oxygen |
During electron transport, energy from ___ is used to pump hydrogen ions into the ___. | NADH and FADH2... intermembrane space |
The proximate (immediate) source of energy for oxidative phosphorylation is___. | Kinetic energy that is released as hydrogen ions diffuse down their concentration gradient |
From the following compounds involved in cellular respiration (Pyruvate,Glucose, ADP, NAD+,O2, Acetyl CoA, NADH, CO2, ATP, CoA, choose those that are the Net Inputs and Net Outpouts of Glycolysis. | Net Inputs- Glucose, NAD+, ADP Net Outputs- ATP, Pyruvate, NADH Neither-CO2, Acetyl CoA, O2, CoA |
From the following compounds involved in cellular respiration(Pyruvate, ADP, O2, NAD+, CoA, Glucose, acetyl CoA, NADH, CO2, ATP), choose those that are net inputs and net outputs of acetyl CoA formation. | Net Inputs- Glucose, ADP, NAD+ Net Outputs- Pyruvate, ATP, NAD Neither- CO2, Acetyl CoA, O2, coenzyme A |
From the following compounds involved in cellular respiration (pyruvate, CO2, ADP, Glucose, NAD+, Acetyl CoA, NADH,ATP, O2, coenzyme A) , choose those that are the net inputs and net outputs of the citric acid cycle. | Net Inputs- NAD+, ADP, Acetyl CoA Net Outputs- CO2, CoA, NADH, ATP Neither- Glucose, O2, Pyruvate |
From the following compounds involved in cellular respiration (ADP, acetyl CoA, pyruvate, NAD+, ATP, CO2, NADH, coenzyme A, O2, glucose), choose those that are the net inputs and net outputs of oxidative phosphorylation. | Net Inputs- ADP, NADH, O2 Net Outputs- ATP, H2O, NAD+ Neither- CO2, acetyl CoA, Glucose, Pyruvate, CoA |
Glycolysis takes place where in the cell? | Cytosol |
Acetyl CoA formation occurs where in the cell? | Mitochondrial matrix |
Citric Acid Cycle occurs where in the cell? | Mitochondrial matrix |
Oxidative Phosphorylation occurs where in the cell? | inner mitochondrial membrane |
When a compound donates (loses) electrons, that compound becomes ___. Such a compound is referred to as an electron donor. | Oxidized |
When a compound accepts (gains) electrons, that compound becomes ___. Such a compound is often referred to as an electron acceptor. | Reduced |
In glycolysis, the carbon-containing compound that functions as the electron donor is ___. | Glucose |
Once the electron donor in glycolysis gives up its electrons, it is oxidized to a compound called ___. | Pyruvate |
___ is the compound that functions as the electron acceptor in glycolysis. | NAD+ |
The reduced form of the electron acceptor in glycolysis is ____. | NADH |
Among the products of glycolysis, which compounds contain energy that can be used by other biological reactions? | Pyruvate, ATP, and nADH |
This describes some aspect of substrate-level phosphorylation in glycolysis, One of the substrates in a molecule derived from the breakdown of glucose. True or False? | True |
This describes some aspect of substrate-level phosphorylation in glycolysis, A bond must be broken between an organic molecule and phosphate before ATP can form. True or False? | True |
This describes some aspect of substrate-level phosphorylation in glycolysis, An enzyme is required in order for the reaction to occur. True or False? | True |
This describes some aspect of substrate-level phosphorylation in glycolysis, The enzymes involved in ATP synthesis must be attached to a membrane to produce ATP. True of False? | False |
This describes some aspect of substrate-level phosphorylation in glycolysis, The phosphate group added to ADP to make ATP comes from free inorganic phosphate ions. True or False? | False |
In mitochondrial electron transport, what is the direct role of O2? | To function as the final electron acceptor in the electron transport chain |
How would anaerobic conditions (when no O2 is present) affect the rate of electron transport and ATP production during oxidative phosphorylation? (Note that you should not consider the effect on ATP synthesis in glycolysis or the citric acid cycle)? | Both electron transport and ATP synthesis would stop |
Why is more ATP made per molecule of NADH than per molecule of FADH2? | Fewer protons are pumped across the inner mitochondrial membrane when FADH2 is the electron donor than when NADH is the electron donor |
Choose:Reamains the same, decreases or goes to zero,or increases, according to the effect that gramicidin would have on each process (electron transport rate, size of the proton gradient, rate of oxygen uptake, rate of ATP synthesis, proton pumping rate) | Remains the Same- Electron transport rate, proton pumping rate, rate of oxygen uptake Decreases (Or goes to zero)- Rate of ATP synthesis, size of the proton gradient |
Name the inputs and outputs of Glycolysis | Inputs: Glucose, NAD+, ADP+Pi Outputs: Pyruvate, NADH, ATP |
Name the inputs and outputs of Acetyl CoA Formation and the Citric Acid Cycle | Inputs: Pyruvate, NAD+,ADP+Pi Outputs:: CO2, NADH, ATP |
Name the inputs and outputs of Oxidative Phosphorylation | Inputs: O2, NADH, ADP +Pi Outputs:Water, NAD+, ATP |
Use your knowledge of the first three stages of cellular respiration to determine which explanation is correct. | It is easier to remove electrons and produce CO2 from compounds with three or more carbon atoms than from a two-carbon compound such as acetyl CoA. |
Under anaerobic conditions (a lack of oxygen), the conversion of pyruvate to acetyl CoA stops. Which of these statements is the correct explanation for this observation? | In the absence of oxygen, electron transport stops. NADH is no longer converted to NAD+, which is needed for the first three stages of cellular respiration. |
Suppose that a cell’s demand for ATP suddenly exceeds its supply of ATP from cellular respiration. Which statement correctly describes how this increased demand would lead to an increased rate of ATP production? | ATP levels would fall at first, decreasing the inhibition of PFK and increasing the rate of ATP production. |
Assume that a muscle cell’s demand for ATP under anaerobic conditions remains the same as it was under aerobic conditions. What would happen to the cell’s rate of glucose utilization? | Glucose utilization would increase a lot. |
Which of these equations best summarizes photosynthesis? | 6 CO2 + 6 H2O → C6H12O6 + 6 O2 |
The light reactions of photosynthesis use _____ and produce _____. | Water.. NADPH |
Choose whether the following are inputs, outputs, or neither from the light reactions. (Glucose, NADPH, NADP+,O2,G3P, ATP, Water, ADP, CO2, Light) | Inputs- Light, ADP, Water, NADP+ Outputs- O2, NADPH, ATP Neither- Glucose, CO2,G3P |
From the following choices, identify those that are the inputs and outputs of the Calvin cycle. (ATP, NADPH, NADP+, Light, O2, CO2, ADP, G3P, Glucose) | Inputs- ATP, CO2, NADPH Outputs- ADP, G3P, NADP+ Neither- Light, O2, Glucose |
In the light reactions, light energy is used to oxidize ___ to ___. | H2O... O2 |
The electrons derived from this oxidation reaction in the light reactions are used to reduce ___ to ___. | NADP+... NADPH |
The Calvin Cycle oxidizes the light-reactions product ____ to ____. | NADPH... NADP+ |
The electrons derived from this oxidation reaction in the Calvin cycle are used to reduce ____ to _____. | CO2... G3P |
CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they... | Fix CO2 into organic acids during the night |
Why are C4 plants able to photosynthesize with no apparent photorespiration? | They use PEP carboxylase to initially fix CO2 |
What is true of the enzyme ribulose bisphosphate carboxylase? | It participates in the Calvin cycle & it has an affinity for both O2 and CO2 |
One carbon dioxide molecule reacts in each "turn" of the Calvin cycle. How many turns of the cycle are required for the synthesis of one glucose molecule? | 6 |
Where do the enzymatic reactions of the Calvin cycle take place? | Stroma of the choloroplast |
Which of the following statements best describes the relationship between photosynthesis and respiration? | Photosynthesis stores energy in complex organic molecules, while respiration releases it |
In a plant cell, where are the ATP synthase complexes located? | Thykaloid membrane and the inner mitochondrial membrane |
As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find 30,000 molecules of ATP consumed, but only 20,000 molecules of NADPH. Where did the extra ATP molecules come from? | Cyclic electron flow |
What does cyclic electron flow in the chloroplast produce? | ATP |
What are the products of noncyclic photophosphorylation? | ATP and NADPH |
Is this true or false regarding the functioning of photosystem II? Light energy excites electrons in an antenna pigment in a photosynthetic unit. | True |
Is this true or false regarding the functioning of photosystem II? The excitation is passed along to a molecule of P680 chlorophyll in the photosynthetic unit. | True |
Is this true or false regarding the functioning of photosystem II? The P680 cholorphyll donates a pair of protons to NADPH, which is thus converted to NADP+ | False |
Is this true or false regarding the functioning of photosystem II? The electron vacancies in P680 are filled by electrons derived from water. | True |
Is this true or false regarding the functioning of photosystem II? The splitting of water yields molecular oxygen as a by-product. | True |
The reaction-center chlorophyll of photosystem I is known as P700 because | This pigment is best at absorbing light with a wavelength of 700 nm. |
In the thylakoid membranes, what is the main role of the antenna pigment molecules? | Harvest photons and transfer light energy to the reaction-center chlorophyll |
A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light are not being absorbed by this pigment? | Red and yellow |
In C3 plants the conservation of water promotes _____. | Photorespiration |
In C4 and CAM plants carbon dioxide is fixed in the _____ of mesophyll cells. | Cytoplasm |
C4 plants differ from C3 and CAM plants in that C4 plants _____. | transfer fixed carbon dioxide to cells in which the Calvin cycle occurs |
Carbon fixation involves the addition of carbon dioxide to _____. | RuBP |
After 3-PGA is phosphorylated, it is reduced by _____. | NADPH |
How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose? | 6 |
In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules? | 3 |
Suppose that the concentration of CO2 available for the Calvin cycle decreased by 50% (because the stomata closed to conserve water).Correctly describe how O2 production would be affected? (Assume that the light intensity does not change.) | The rate of O2 production would decrease because the rate of ADP and NADP+ production by the Calvin cycle would decrease. |