Most of the CO₂ from cellular respiration is released during
a. Stage 1: Glycolysis
b. Stage 2: Pyruvate oxidation
c. Stage 2: The citric acid cycle
d. Stage 3: Oxidative phosphorylation

Question

Most of the CO₂ from cellular respiration is released during

a. Stage 1: Glycolysis

b. Stage 2: Pyruvate oxidation

c. Stage 2: The citric acid cycle

d. Stage 3: Oxidative phosphorylation

Accepted Answer

Hi everyone. Let's look at our next choice. It says cellular respiration is divided into the following four stages. Number one guy, colossus, number two Peruvian acid metabolism number three Krebs cycle number four oxidative phosphor relation identify the option that includes all stages in which carbon dioxide is not produced. Must circle that not. So, I remember that we are looking for stages where there's no C. 02 generated. So I'm going to just highlight that, not in blue so we can focus on that. Now. Let's look at our four stages here. Number one is glycol icis. Well, that's the step that converts glucose to Piru bait. It does produce A T P and N A D H. However, no C 02 is produced in this step. That's because glucose it's being split, glucose is a six carbon sugar. Piru beta three carbon molecule. So it's becoming smaller but no carbon is being lost in the form of C. 02, glucose is just splitting into 23 carbon. Piru molecules. So I'm going to highlight in blue step number one. To help us remember that, that is one of the steps where CO2 is not produced. Now let's look at number two. Piru vic acid metabolism. Well up above we went glucose to piru bait. Now, Piru weak acid metabolism is when our piru bait will be converted into a seal. Co a and in this step is a three carbon molecule acetyl coa A is a two carbon molecule. I'm going for a three carbon molecule to two carbon molecule and it does produce co two one of those carbon carbon atoms from piru bait is lost in the form of C. 02. So I'm not going to highlight that one Because it does produce co two. I'll put a little red line through it to help us remember. Next is number three. The Krebs cycle. And hopefully the Krebs cycle, it's pretty straightforward to recall that it does produce CO two. That's our major cycle here. You start with your acetyl co A. Goes into the cycle and C. 0. 2 is produced for every two more. Uh there's two carbon atoms in a molecule of acetyl coa A. So when a molecule of acetyl coa goes through this cycle to seO tools are produced um for every molecule of acetyl coa A. So I'm gonna put a red line through Krebs cycle because that is a producer of C. 02. And then finally number four oxidative phosphor relation. Oxidative phosphor relation is that process by which um electron donors uh N A. D. H. And F A. D. H two donate electrons to the electron transport chain. Those that energy from that process causes protons to be pumped across the membrane. Those protons then flow downhill through the enzyme A TB keenness and that's where the A. T. P is produced. That is the cells harvest from the breakdown of glucose. So eight ep is produced. But no C 02 from the step you're not losing any carbons from a carbon molecule. so that I will highlight in blue because step number four oxidative phosphor relation no C 02 is produced. So we have a number one and number four where no C 02 is produced. So we'll go down to our answer choices and we see that choice D is indeed one and four. That corresponds up here. One and four are the two steps like Alexis and oxidative phosphor relation are the stages in which carbon dioxide is not produced in those four stages of cellular respiration. See you in the next video.

Most of the CO₂ from cellular respiration is released during
a. Stage 1: Glycolysis
b. Stage 2: Pyruvate oxidation
c. Stage 2: The citric acid cycle
d. Stage 3: Oxidative phosphorylation

Verified video answer for a similar problem:

Key Concepts

Cellular Respiration

Citric Acid Cycle

Glycolysis