What is the third step in cellular respiration?(1 point)
Responses
the Krebs cycle
the Krebs cycle
the electron transport chain
the electron transport chain
the citric acid cycle
the citric acid cycle
glycolysis
the citric acid cycle
The third step in cellular respiration is the citric acid cycle, also known as the Krebs cycle.
The third step in cellular respiration is the Krebs cycle, also known as the citric acid cycle. To understand this, let me explain how to break down glucose to produce energy in a cell.
The first step is glycolysis, where glucose is broken down into two pyruvate molecules in the cytoplasm of the cell. This process does not require oxygen and yields a small amount of ATP.
The second step is the Krebs cycle, which takes place in the mitochondria of the cell. In this cycle, each pyruvate molecule is converted into a molecule called acetyl-CoA. Acetyl-CoA then enters the Krebs cycle, where it is completely broken down, releasing carbon dioxide and producing high-energy molecules like NADH and FADH2.
The third step is the electron transport chain, which takes place in the inner membrane of the mitochondria. The NADH and FADH2 molecules generated in the previous steps donate their electrons to the electron transport chain. As the electrons move through the chain, their energy is used to pump protons (H+) across the membrane, creating a proton gradient. This gradient drives the production of ATP through a process called oxidative phosphorylation.
So, to answer your question, the third step in cellular respiration is the electron transport chain. But it is important to note that the Krebs cycle, also known as the citric acid cycle, comes before the electron transport chain.