21.3 Aerobic respiration

ATP produced in active cells acts as an energy carrier to provide energy to inactive cells.

• True

• False

Coenzyme A serves as an acetyl donor to donate an acetyl group to the 4-C compound in the Krebs cycle in aerobic respiration.

• True

• False

ATP can still be produced in glycolysis if there is no oxygen.

• True

• False

[DSE PP]

Which of the following correctly lists the substances formed in the Krebs cycle?

• water and NADH

• water and carbon dioxide

• carbon dioxide and NADH

• water, carbon dioxide and NADH

[DSE 2020] (73% correct)

Which of the following combinations correctly matches the stages of cellular respiration and the metabolites produced?

• Stage: glycolysis

  Metabolite produced: acetyl-CoA

• Stage: glycolysis

  Metabolite produced: ATP

• Stage: Krebs cycle

  Metabolite produced: NAD

• Stage: Krebs cycle

  Metabolite produced: pyruvate

[DSE 2013] (67% correct)

Which of the following combinations best describes the processes involved in respiration?

• O₂ is required: Conversion of pyruvate to acetyl-CoA

  CO₂ is released: Glycolysis

• O₂ is required: Conversion of pyruvate to acetyl-CoA

  CO₂ is released: Krebs cycle

• O₂ is required: Oxidative phosphorylation

  CO₂ is released: Glycolysis

• O₂ is required: Oxidative phosphorylation

  CO₂ is released: Krebs cycle

[DSE 2016] (65% correct)

Which of the following processes in aerobic respiration release NADH?

(1) glycolysis

(2) Krebs cycle

(3) oxidative phosphorylation

• (1) and (2) only

• (1) and (3) only

• (2) and (3) only

• (1), (2) and (3)

Which of the following is/are produced in glycolysis and enter mitochondria?

*There may be more than ONE answer

• NAD

• NADH

• pyruvate

• acetyl-CoA