How many CO2 molecules are released in the Krebs cycle if two molecule of glucose is oxidized?*1 point24832

1. Break Down the Problem

To determine how many CO₂ molecules are released in the Krebs cycle from the oxidation of two molecules of glucose, we first need to understand the relationship between glucose and the Krebs cycle. Each glucose molecule undergoes glycolysis, producing pyruvate, which then enters the Krebs cycle.

2. Relevant Concepts

• Each molecule of glucose (C₆H₁₂O₆) produces 2 molecules of pyruvate after glycolysis.
• Each pyruvate molecule enters the Krebs cycle where it is converted to acetyl CoA.
• For each acetyl CoA entering the Krebs cycle, 2 molecules of CO₂ are released.

3. Analysis and Detail

1. Oxidation of Glucose:

   • 1 glucose → 2 pyruvate.
   • Therefore, 2 glucose → 4 pyruvate.

2. Krebs Cycle Process:

   • Each pyruvate converts to acetyl CoA and enters the Krebs cycle.
   • Each acetyl CoA produces 2 CO₂ in the Krebs cycle.

3. Calculating CO₂ from 4 Pyruvate:

   • 4 pyruvate → 4 acetyl CoA.
   • CO₂ produced from 4 acetyl CoA = 4 acetyl CoA × 2 CO₂/acetyl CoA = 8 CO₂.

4. Verify and Summarize

Since 2 CO₂ are released per acetyl CoA and we have 4 acetyl CoA from the oxidation of 2 glucose, the total CO₂ released is indeed 8 molecules.

Final Answer

The total number of CO₂ molecules released in the Krebs cycle when two molecules of glucose are oxidized is 8 CO₂ molecules.