AP Biology Unit 3 Review

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What is the Krebs Cycle?

Back

The Krebs Cycle, also known as the Citric Acid Cycle, is a series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins. It produces CO2, ATP, NADH, and FADH2.

Front

What is the role of NAD+ in cellular respiration?

Back

NAD+ is a coenzyme that acts as an electron carrier in cellular respiration. It is reduced to NADH during glycolysis and the Krebs Cycle, allowing for the continuation of glycolysis and the production of ATP.

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What is fermentation and when does it occur?

Back

Fermentation is an anaerobic process that allows for the regeneration of NAD+ from NADH, enabling glycolysis to continue producing ATP in the absence of oxygen.

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What is the significance of splitting water molecules in photosynthesis?

Back

Splitting water molecules during photosynthesis releases oxygen as a by-product and provides electrons needed for the light-dependent reactions, specifically in photosystem II.

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Where does substrate binding occur on an enzyme?

Back

The substrate binds to the active site of an enzyme, which is specifically shaped to fit the substrate, facilitating the chemical reaction.

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What is oxidative phosphorylation?

Back

Oxidative phosphorylation is the final stage of cellular respiration, occurring in the mitochondria, where ATP is produced using the energy released from the electron transport chain and the flow of protons back into the mitochondrial matrix.

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What are the main products of glycolysis?

Back

The main products of glycolysis are 2 molecules of pyruvate, 2 molecules of NADH, and a net gain of 2 ATP.

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What is chemiosmosis?

Back

Chemiosmosis is the movement of ions across a selectively permeable membrane, down their electrochemical gradient, which is used to generate ATP in cellular respiration and photosynthesis.

Front

What is the difference between aerobic and anaerobic respiration?

Back

Aerobic respiration requires oxygen and produces more ATP (up to 36-38 ATP), while anaerobic respiration occurs without oxygen and produces less ATP (2 ATP) through processes like fermentation.

Front

What is the function of ATP synthase?

Back

ATP synthase is an enzyme that synthesizes ATP from ADP and inorganic phosphate during oxidative phosphorylation, utilizing the proton gradient created by the electron transport chain.