🔄 Krebs Cycle

What two-carbon molecule combines with oxaloacetate to form citrate?

Acetyl Coenzyme A

What is the main objective of the Krebs cycle?

To generate NADH and FADH2 for oxidative phosphorylation.

What is released when citrate is converted into a five-carbon molecule?

Carbon dioxide (CO2) and NADH

What happens to NAD during the conversion of citrate into a five-carbon molecule?

NAD is reduced to NADH.

What type of reaction occurs when NAD is reduced to NADH in the Krebs cycle?

Oxidative decarboxylation.

What is generated from ADP during the Krebs cycle?

1 ATP.

What is the mechanism called when ATP is produced directly in the Krebs cycle?

Substrate-level phosphorylation.

What is FAD reduced to during the Krebs cycle?

FADH2.

What is the final product of the Krebs cycle that regenerates to restart the cycle?

Oxaloacetate.

How many NADH molecules are produced from one pyruvate molecule in the Krebs cycle?

Four NADH molecules.

How many carbon dioxide molecules are produced from one pyruvate in the Krebs cycle?

Three carbon dioxide molecules.

How many ATP molecules are generated from one pyruvate in the Krebs cycle?

One ATP molecule.

What is decarboxylation?

The removal or loss of carbon dioxide (CO2).

What does oxidation in the context of the Krebs cycle indicate?

NAD becoming reduced,

What is substrate-level phosphorylation?

The production of ATP without using the electron transport chain or ATP synthase.

What are the products of the Krebs cycle?

• 3x Carbon dioxide (CO2)

• 4x NADH

• 1x FADH2

• 1x ATP

What do NADH and FADH2 feed into after being produced in the Krebs cycle?

Oxidative phosphorylation.

Which stage follows the Krebs cycle in cellular respiration?

Oxidative phosphorylation.

What is the role of oxaloacetate in the Krebs cycle?

It combines with the acetyl coenzyme A to form citrate and is regenerated to continue the cycle.

What type of reaction is ATP generation during the Krebs cycle considered?

Substrate-level phosphorylation.

Which molecules are characterized as a product feeding directly into oxidative phosphorylation?

NADH and FADH2.

What compound is exhaled as a result of decarboxylation processes in the Krebs cycle?

Carbon dioxide (CO2).