Krebs cycle

In this episode, we explore the Krebs cycle, also known as the citric acid cycle, a central pathway in cellular respiration. Learn about its key steps, enzymes involved, and its role in energy production. Building on previous episodes on enzymes, metabolic pathways, and glycolysis, this episode sets the stage for understanding ATP production, oxidative phosphorylation, and cellular respiration in upcoming episodes.

Check your understanding

These are the same multiple-choice questions you will see in the Quiz section after you listen to the episode. Use them here to preview or review the answers.

Where does the Krebs cycle occur in eukaryotic cells?

  1. Cytoplasm
  2. Nucleus
  3. Mitochondrial matrix
  4. Endoplasmic reticulum
  5. Golgi apparatus
  6. Plasma membrane

What are the main products of the Krebs cycle per turn?

  1. 3 NADH
  2. 2 CO2
  3. 1 ATP (or GTP)
  4. 2 FADH2
  5. 4 Pyruvate
  6. 1 Acetyl-CoA

What enzyme catalyzes the formation of citrate?

  1. Aconitase
  2. Citrate synthase
  3. Isocitrate dehydrogenase
  4. Succinate dehydrogenase
  5. Malate dehydrogenase
  6. Pyruvate kinase

Which molecules produced in the Krebs cycle are used in the electron transport chain?

  1. NADH
  2. FADH2
  3. CO2
  4. Acetyl-CoA
  5. GTP
  6. ATP

What is the role of oxaloacetate in the Krebs cycle?

  1. Combines with acetyl-CoA to form citrate
  2. Stores energy for ATP production
  3. Releases carbon dioxide as a byproduct
  4. Acts as an intermediate in glycolysis
  5. Is regenerated at the end of the cycle
  6. Inhibits the electron transport chain

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