Quiz 6: Cellular Respiration

in the absence of oxygen, suppose a single yeast cell undergoes fermentation and uses 100 molecules of glucose. How many molecules of ATP will be generated?

200

for each mole of glucose (C6H12O6) oxidized by cellular respiration, how many moles of CO2 are released in the citric acid cycle (see the accompanying figure)?

4

the main function of cellular respiration is to produce.

ATP

the enzyme phosphofructokinase (PFK) catalyzes a key step in glycolysis. PFK is inhibited by high levels of which of the following molecules?

ATP and citrate

chemiosmosis in mitochondria directly results in the synthesis of:

ATP.

which of the following statements best describes the primary role played by oxygen in cellular respiration?

It serves as the final acceptor for electrons from the electron transport chain.

following glycolysis and the citric acid cycle, but before the electron transport chain and oxidative phosphorylation, the carbon skeleton of glucose has been broken down to CO2 with some net gain of ATP. Most of the energy from the original glucose molecule at that point in the process, however, is stored in the form of which of the following molecules?

NADH

during which stage of cellular respiration is the majority of the ATP produced?

electron transport chain

in chemiosmosis, what is the most direct source of energy that is used to convert ADP + i to ATP?

energy released from movement of protons through ATP synthase, down their electrochemical gradient

the anaerobic breakdown of glucose is called:

fermentation

from the beginning of glycolysis to the end of the Krebs cycle, what has the cell gained from the breakdown of each molecule of glucose?

four molecules of ATP, 10 of NADH, and two of FADH2

during glycolysis, two ATP molecules are "spent" in order to convert glucose to the highly reactive molecule:

fructose 1,6-bisphosphate.

identify the stage (or stages) of cellular respiration that occurs entirely outside of the mitochondria.

glycolysis

in human muscle cells, fermentation (by itself) produces:

lactate

which parts of the mitochondria are directly involved in the synthesis of ATP during chemiosmosis?

matrix and inner membrane

where are the proteins of the electron transport chain located?

mitochondrial inner membrane

when oxygen is present:

most animal cells utilize aerobic cellular respiration.

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

the end product of glycolysis is:

two pyruvate molecules

can energy be harvested by the cells from glucose without oxygen?

yes, but much less than with oxygen