Question

step 2 - krebs cycle

1. in the krebs cycle, \square atp and \square nadh are created.
2. the two electron \square, nadh and fadh₂, travel to the electron transport chain.
3. two molecules of carbon dioxide are given off during the conversion of pyruvate to acetyl-coa and \square more are given off during the krebs cycle to total \square.

Explanation:

Question 30

Step1: Recall Krebs Cycle ATP production

In one turn of the Krebs Cycle, 1 ATP (or GTP, which is converted to ATP) is produced. Since the cycle runs twice per glucose molecule (because 2 acetyl - CoA are formed from 1 glucose), but for the per - turn or the net in terms of the cycle's production, per acetyl - CoA (per turn of the cycle), 1 ATP is produced. And for NADH, per turn of the Krebs Cycle, 3 NADH are produced, and since the cycle runs twice (because 2 acetyl - CoA enter the cycle), but the question is about the Krebs Cycle (per acetyl - CoA? Wait, no, the Krebs Cycle processes one acetyl - CoA at a time, but since glycolysis produces 2 pyruvates, which become 2 acetyl - CoA, the cycle runs twice. But the standard numbers: per acetyl - CoA (per turn of the cycle), 1 ATP, 3 NADH, and 1 FADH₂. Wait, but the question is "In the Krebs Cycle, [ ] ATP and [ ] NADH are created." So per turn of the Krebs Cycle (processing one acetyl - CoA), 1 ATP and 3 NADH? Wait, no, actually, the correct numbers: for one acetyl - CoA (one turn of the Krebs Cycle): 1 ATP (or GTP), 3 NADH, and 1 FADH₂. But sometimes, when considering the entire process from glucose, but the question is about the Krebs Cycle. Wait, maybe the question is considering per glucose? No, the Krebs Cycle is for each acetyl - CoA. Wait, let's check the standard Krebs Cycle outputs:

• 1 ATP (or GTP) per turn.
• 3 NADH per turn.
• 1 FADH₂ per turn.

But since two acetyl - CoA enter the Krebs Cycle (from one glucose), the total per glucose would be 2 ATP, 6 NADH, and 2 FADH₂. But the question is "In the Krebs Cycle" – maybe it's per turn (per acetyl - CoA). So the answer for ATP is 1 (per turn) and NADH is 3 (per turn)? Wait, no, maybe the question is simplified. Wait, the standard answer for the Krebs Cycle (per acetyl - CoA): 1 ATP, 3 NADH. Wait, but let's confirm. The Krebs Cycle (Citric Acid Cycle) for one acetyl - CoA:

• 1 GTP (converted to ATP) → 1 ATP.
• 3 NADH.
• 1 FADH₂.

So the blanks should be 1 ATP and 3 NADH? Wait, but maybe the question is considering the cycle running twice (for two acetyl - CoA), so 2 ATP and 6 NADH? But that's for the entire glucose breakdown. Wait, the diagram has "x2" in the middle, which suggests that the cycle runs twice. Let's re - examine the diagram. The diagram shows "x2", so maybe the numbers are for the two turns (processing two acetyl - CoA). So for two turns (two acetyl - CoA):

• ATP: 2 (1 per turn × 2)
• NADH: 6 (3 per turn × 2)

But the question is "In the Krebs Cycle, [ ] ATP and [ ] NADH are created." Maybe the question is using the simplified numbers where per glucose (two turns of the cycle), 2 ATP and 6 NADH? Wait, no, maybe the question is per turn. Wait, the problem is a fill - in - the - blank, and the standard answers for the Krebs Cycle (per acetyl - CoA, one turn): 1 ATP, 3 NADH. But the diagram has "x2", so maybe the answer is 1 ATP (per turn) and 3 NADH (per turn), but if the cycle runs twice, 2 ATP and 6 NADH. Wait, maybe the question is simplified, and the answers are 1 ATP and 3 NADH (per turn) or 2 ATP and 6 NADH (per glucose, two turns). Wait, let's check the diagram. The diagram has "x2" in the middle, so it's considering two turns (two acetyl - CoA). So for two turns:

• ATP: 2 (1 per turn × 2)
• NADH: 6 (3 per turn × 2)

But maybe the question is using the per - turn numbers. Wait, this is confusing. Wait, the standard textbook answer: In the Krebs Cycle (per acetyl - CoA, one turn), 1 ATP, 3 NADH, 1 FADH₂. So if the question is about one turn, 1 and 3. If about two turns (two acetyl - CoA), 2 and 6. Give…

Answer:

s:

1. 2 ATP and 6 NADH (or if per turn, 1 and 3; but based on two acetyl - CoA, 2 and 6)
2. carriers
3. 4 more, total 6