Where does the citric acid cycle occur in eukaryotes? a. in the cytosol of cells b. in the intermembrane space of mitochondria c. in the inner membrane of mitochondria d. in the matrix of mitochondria

What does the chemiosmotic hypothesis claim?

a. ATP is generated using phosphates taken from intermediates in the electron transport chain.

b. ATP is generated using a phosphate gradient produced by glycolysis and the citric acid cycle.

c. ATP is generated using a proton-motive force that is produced by the electron transport chain.

d. Water is generated using electrons taken from NADH and FADH₂ and transported through the electron transport chain.

After glucose is fully oxidized by glycolysis, pyruvate processing, and the citric acid cycle, where is most of its energy stored?

Which of the following correctly describe the fermentation pathway? Select True or False for each statement.

T/F It includes a reaction that oxidizes NADH to NAD⁺.

T/F It synthesizes ATP by substrate-level phosphorylation.

T/F It includes a reaction that reduces NAD⁺ to NADH.

T/F It synthesizes electron acceptors, so that cellular respiration can continue.

Compare and contrast substrate-level phosphorylation and oxidative phosphorylation.

If you were to expose cells that are undergoing aerobic respiration to a radioactive oxygen isotope in the form of O₂, which of the following molecules would you expect to be radiolabeled?

a. Pyruvate

b. Water

c. NADH

d. CO₂

In step 3 of the citric acid cycle, the enzyme isocitrate dehydrogenase is regulated by NADH. Compare and contrast the regulation of this enzyme with the regulation of phosphofructokinase in glycolysis.

Explain the relationship between electron transport and oxidative phosphorylation. How do uncoupling proteins 'uncouple' this relationship in brown adipose tissue?

The researchers who observed that magnetite was produced by bacterial cultures from the deep subsurface carried out a follow-up experiment. These biologists treated some of the cultures with a drug that poisons the enzymes involved in electron transport chains. In cultures where the drug was present, no more magnetite was produced. Does this result support or undermine their hypothesis that the bacteria in the cultures perform cellular respiration? Explain your reasoning.

Cyanide (C ≡ N⁻) blocks complex IV of the electron transport chain. Suggest a hypothesis for what happens to the ETC when complex IV stops working. Your hypothesis should explain why cyanide poisoning in humans is fatal.

Early estimates suggested that the oxidation of glucose via aerobic respiration would produce 38 ATP. Based on what you know of the theoretical yields of ATP from cellular respiration, show how this total was determined. Why do biologists now think this amount of ATP per molecule of glucose is not achieved in cells?