respiration

• What is the overall purpose of respiration?

  To produce ATP
• Where does glycolysis occur?

  In the cytoplasm
• Why does glycolysis occur in both anaerobic and aerobic respiration?

  It does not require oxygen
• What are the three key steps of glycolysis?

  1. Phosphorylation of glucose
  2. Splitting into triose phosphate
  3. Oxidation to form pyruvate
• How many ATP molecules are used in the phosphorylation of glucose?

  Two ATP molecules
• What is glucose phosphate?

  A high-energy molecule formed from glucose
• What does triose phosphate refer to?

  A three-carbon sugar with a phosphate group
• What happens to triose phosphate during glycolysis?

  It is oxidized to form pyruvate
• What coenzyme is involved in the oxidation of triose phosphate?

  NAD
• What is produced when NAD is reduced?

  Reduced NAD or NADH
• How can you tell that triose phosphate is oxidized?

  Because NAD picks up a hydrogen
• How many molecules of ATP are released during the oxidation of triose phosphate?

  Two molecules of ATP
• What is the net gain of ATP from glycolysis?

  Two ATP molecules
• What happens to pyruvate after glycolysis?

  It is actively transported into mitochondria
• How many reduced NADH molecules are produced in glycolysis?

  Two reduced NADH molecules
• What are the key outcomes of glycolysis?

  • Two molecules of pyruvate
  • Net gain of two ATP
  • Two reduced NADH
• What will the reduced NADH be used for in respiration?

  In the final step, oxidative phosphorylation
• What is the total number of ATP produced during glycolysis?

  Four ATP produced
• Why do we describe the ATP gain from glycolysis as a net gain of two?

  Because two ATP were used in the process
• What are the two processes discussed in the video?

  Link reaction and Krebs cycle
• What is the first stage of aerobic respiration?

  Glycolysis
• Where do the link reaction and Krebs cycle occur?

  Mitochondrial matrix
• What must be transported from the cytoplasm to the mitochondrial matrix?

  Pyruvate and reduced NAD (NADH)
• What happens to pyruvate in the link reaction?

  It is oxidized into acetate
• What is lost from pyruvate during its oxidation?

  Hydrogen
• What does NAD do during the link reaction?

  It picks up hydrogen and becomes NADH
• What is the three-carbon molecule produced from glycolysis?

  Pyruvate
• What is the purpose of converting acetate into acetyl CoA?

  To enter the Krebs cycle
• How many products are made in the link reaction from one round?

  Three products
• What are the products of the link reaction for one glucose molecule?

  Two of each product
• What happens when acetyl CoA enters the Krebs cycle?

  It reacts with a four-carbon molecule
• What happens to the six-carbon molecule during the Krebs cycle?

  It loses carbon and becomes a four-carbon molecule
• What is produced when the six-carbon molecule is oxidized?

  Two carbon dioxide molecules
• What coenzymes are reduced during the Krebs cycle?

  NAD and FAD
• How many reduced NAD and FAD are produced in one round of the Krebs cycle?

  Three reduced NAD and one reduced FAD
• What is the total number of products from the Krebs cycle for one glucose molecule?

  Six reduced NAD, two reduced FAD, two ATP, and four CO2
• What are the key steps in the link reaction?

  • Pyruvate is oxidized to acetate
  • NAD is reduced to NADH
  • Acetate combines with coenzyme A to form acetyl CoA
• What are the main steps in the Krebs cycle?

  1. Acetyl CoA reacts with a four-carbon molecule
  2. Six-carbon molecule undergoes redox reactions
  3. Produces ATP, reduced NAD, and reduced FAD
  4. Releases carbon dioxide
• What is the relationship between the link reaction and the Krebs cycle?

  • Link reaction produces acetyl CoA
  • Acetyl CoA enters the Krebs cycle
  • Both occur in the mitochondrial matrix
• Who is the instructor for the A Level Biology course?

  1. Ik