Understanding the Krebs Cycle

What is the primary function of the Krebs cycle?

• To produce glucose for photosynthesis.

• To generate energy in the form of ATP and electron carriers (NADH and FADH2) for cellular respiration.

• To synthesize fatty acids for storage.

• To break down proteins into amino acids.

Where in the cell does the Krebs cycle occur?

• Nucleus

• Mitochondria

• Cytoplasm

• Ribosome

What are the starting materials for the Krebs cycle?

• Pyruvate and NADH

• Fumarate and succinate

• Acetyl-CoA and oxaloacetate

• Citrate and malate

Name one product of the Krebs cycle that is used in the electron transport chain.

• FADH2

• NADH

• ATP

• Acetyl-CoA

How many ATP molecules are produced directly from one turn of the Krebs cycle?

• 1 ATP

• 2 ATP

• 3 ATP

• 5 ATP

What role does acetyl-CoA play in the Krebs cycle?

• Acetyl-CoA is produced during the Krebs cycle.

• Acetyl-CoA is a byproduct of the Krebs cycle.

• Acetyl-CoA serves as the starting molecule for the Krebs cycle, combining with oxaloacetate to produce citrate.

• Acetyl-CoA is used to regenerate oxaloacetate.

Which enzyme catalyzes the conversion of citrate to isocitrate?

• Malate dehydrogenase

• Fumarase

• Aconitase

• Citrate synthase

What is the significance of NADH and FADH2 produced in the Krebs cycle?

• NADH and FADH2 are significant as they provide electrons for ATP production in the electron transport chain.

• NADH and FADH2 are only important for fatty acid synthesis.

• NADH and FADH2 are waste products of the Krebs cycle.

• NADH and FADH2 are used to synthesize glucose directly.

How does the Krebs cycle contribute to cellular respiration?

• The Krebs cycle produces glucose for energy storage.

• The Krebs cycle generates electron carriers and ATP, essential for energy production in cellular respiration.

• The Krebs cycle directly consumes oxygen to generate ATP.

• The Krebs cycle is responsible for protein synthesis in cells.

What are the main regulatory points of the Krebs cycle?

• Citrate synthase, isocitrate dehydrogenase, and alpha-ketoglutarate dehydrogenase

• Malate synthase

• Fumarase

• Succinate dehydrogenase