Oxidation of Pyruvate and Citric Acid Cycle

What is the purpose of the preparatory phase in cellular respiration?

• To convert pyruvate into glucose

• To produce ATP

• To convert glucose into pyruvate

• To release carbon dioxide

Which enzyme converts pyruvate into acetyl-CoA?

• pyruvate decarboxylase

• pyruvate kinase

• pyruvate dehydrogenase

• pyruvate carboxylase

What is the main product of the oxidation of pyruvate?

• lactic acid

• acetyl-CoA

• glucose

• ethanol

What is the role of NAD+ in the oxidation of pyruvate?

• NAD+ acts as a catalyst in the oxidation of pyruvate.

• NAD+ has no role in the oxidation of pyruvate.

• NAD+ acts as an electron acceptor in the oxidation of pyruvate.

• NAD+ acts as an electron donor in the oxidation of pyruvate.

What is the first step of the citric acid cycle?

• Hydrolysis of citrate to form oxaloacetate

• Decarboxylation of citrate to form isocitrate

• Phosphorylation of isocitrate to form alpha-ketoglutarate

• Condensation of acetyl-CoA with oxaloacetate to form citrate

Which molecule combines with acetyl-CoA to form citrate?

• pyruvate

• malate

• succinate

• oxaloacetate

What is the purpose of the citric acid cycle?

• The purpose of the citric acid cycle is to produce carbon dioxide.

• The purpose of the citric acid cycle is to synthesize glucose.

• The purpose of the citric acid cycle is to generate energy through the oxidation of acetyl-CoA.

• The purpose of the citric acid cycle is to store energy in the form of ATP.

Which enzyme is responsible for the conversion of citrate to isocitrate?

• fumarase

• isocitrate dehydrogenase

• citrate synthase

• aconitase

What is the final product of the citric acid cycle?

• CO2

• ATP

• Glucose

• NADH

How many ATP molecules are produced directly in the citric acid cycle?

• 3

• 5

• 1

• 10