Cellular Respiration Quiz

Where in the cell do the link reaction and the Krebs cycle take place?

• In the cytoplasm

• In the intermembrane space of the mitochondria

• In the mitochondrial matrix

• On the inner mitochondrial membrane

In the link reaction, pyruvate is converted into an acetyl group. What other molecules are produced during this process?

• ATP and Reduced FAD

• CO₂ and Reduced NAD

• Acetyl CoA and ATP

• CO₂ and FAD

What is the primary role of Coenzyme A in cellular respiration?

• To remove a carbon atom from pyruvate

• To transport hydrogen atoms to the electron transport chain

• To pick up the 2-carbon acetyl group and deliver it to the Krebs cycle

• To produce ATP through substrate-level phosphorylation

The Krebs cycle begins when Acetyl CoA joins with a 4-carbon molecule to create a 6-carbon molecule. What are these 4-carbon and 6-carbon molecules, respectively?

• Citrate and Oxaloacetate

• Pyruvate and Citrate

• Oxaloacetate and Citrate

• Malate and Oxaloacetate

What is the technical term for the removal of hydrogen from a molecule, a key process in the Krebs cycle?

• Decarboxylation

• Dehydrogenation

• Carboxylation

• Hydrolysis

From a single molecule of glucose, what is the total number of reduced coenzymes produced *only* during the link reactions and Krebs cycle stages?

• 6 Reduced NAD and 2 Reduced FAD

• 8 Reduced NAD and 2 Reduced FAD

• 6 Reduced NAD and 6 CO₂

• 2 ATP and 8 Reduced NAD

How many molecules of CO₂ and ATP are produced in a single turn of the Krebs cycle?

• 1 CO₂ and 2 ATP

• 2 CO₂ and 1 ATP

• 3 CO₂ and 1 ATP

• 1 CO₂ and 1 ATP

For each molecule of glucose that begins respiration, how many times do the link reaction and the Krebs cycle occur?

• Once and twice

• Twice and once

• Twice and twice

• Once and once

What key molecule is regenerated at the end of the Krebs cycle, ready to combine with the next Acetyl CoA?

• Citrate

• Pyruvate

• Coenzyme A

• Oxaloacetate

What is the main purpose of the Krebs cycle in aerobic respiration?

• To directly produce a large amount of ATP

• To use up the CO₂ produced during glycolysis

• To produce a large quantity of reduced NAD and reduced FAD

• To regenerate the pyruvate needed for the link reaction