SBI4U Chapter 2.2 Pyruvate Oxidation and Krebs Cycle

Which of the following does not happen during Pyruvate oxidation?

• A CO₂ portion is removed per molecule of pyruvate.

• NAD+ is reduced

• Coenzyme A is attached to the remaining acetic acid portion (acetyl group).

• Oxygen is oxidized

Which of the following is the correct overall equation of pyruvate oxidation.

• 2 pyruvate + 2 NAD+ + 2 CoA -----> 2 acetyl-CoA + 2 NADH + 2H+ + 2 CO2

• 2 pyruvate + 2 NAD+ + 4 CoA -----> 4 acetyl-CoA + 2 NADH + 2H+ + 2 CO2

• 2 pyruvate + 2 NAD+ + 4 CoA -----> 2 acetyl-CoA + 2 NADH + 2H+ + 4 CO2

T/F - Almost all molecules that are catabolized for energy are converted into acetyl-CoA, including proteins, lipids, and carbohydrates.

• True

• False

T/F - If the body does not need energy, acetyl-CoA is channelled into an anabolic pathway that synthesizes lipids as a way of storing large amounts of energy as fat.

• True

• False

T/F - The Krebs cycle is a cyclic process because the product of step 8, is the reactant in step 1

• True

• False

The following is the overall chemical equation for the Krebs cycle:

• oxaloacetate + acetyl-CoA + ADP + Pi + 3NAD1 + FAD -->

  CoA + ATP + 3NADH + 3H+ + FADH2 + 2CO2 + oxaloacetate

• oxaloacetate + acetyl-CoA + ADP + Pi + 3NAD+ + 6FAD -->

  CoA + ATP + 3NADH + 3H+ + 6FADH2 + 2CO2 + oxaloacetate

• oxaloacetate + acetyl-CoA + ADP + Pi + 6NAD1 + FAD -->

  CoA + ATP + 6NADH + 3H+ + FADH2 + 2CO2 + oxaloacetate

T/F - By the end of the Krebs cycle, the original glucose molecule is entirely consumed and leaves the process as six low-energy CO2 molecules, which are released by the cell as waste.

• True

• False

At the end of the krebs cycle the 6 carbons in the original molecule are converted to _____ carbon dioxides during pyruvate oxidation and _____ carbon dioxides during the krebs cycle.

• 2, 4

• 4, 2

• 1, 5

• 5, 1

Which process is the largest contributor to the release of CO₂ 

• Citric Acid Cycle or Krebs Cycle
• Pyruvate Oxidation
• Glycolysis
• Oxidative Phosphorylation 

Tags

NGSS.HS-LS1-7

Which process least amount of ATP in cells? 

• Glycolysis
• Citric Acid cycle
• Lactic acid Fermentation
• Pyruvate Oxidation

Tags

NGSS.HS-LS2-3