During which phase of cellular respiration is carbon dioxide produced?

The Krebs cycle, also known as the citric acid cycle, is the phase of cellular respiration that produces carbon dioxide. This cycle occurs in the mitochondria and is a crucial part of cellular respiration where acetyl-CoA, derived from pyruvate (produced in glycolysis), is further oxidized. Within this cycle, organic molecules undergo a series of enzymatic reactions, leading to the release of carbon dioxide as a waste product.

During these reactions, high-energy electron carriers such as NADH and FADH2 are generated, which will later be utilized in the electron transport chain to produce ATP. The emission of carbon dioxide during the Krebs cycle is a vital part of cellular metabolism, as it represents the breakdown of carbon compounds and is how cells dispose of carbon after energy extraction.

Other phases, such as glycolysis, do not produce carbon dioxide; instead, they focus on breaking down glucose into pyruvate without releasing CO2. The electron transport chain mainly involves transferring electrons and pumping protons to create a gradient for ATP synthesis, and fermentation is an anaerobic process that allows for ATP production without oxygen and does not generate carbon dioxide in the same context as the Krebs cycle.