What role does cellular respiration play in the carbon cycle?
It removes CO2 from the atmosphere during glycolysis.
It removes CO2 from the atmosphere during the citric acid cycle.
It releases CO2 to the atmosphere during acetyl CoA formation.
It releases CO2 to the atmosphere during electron transport.
Cellular respiration plays a role in the carbon cycle by releasing CO2 to the atmosphere during the citric acid cycle, acetyl CoA formation, and electron transport. While glycolysis does not directly remove CO2 from the atmosphere, it is the first step in the process of cellular respiration and ultimately leads to the release of CO2 during the citric acid cycle and subsequent steps. Therefore, both the second and fourth options are correct.
Cellular respiration plays a significant role in the carbon cycle by both removing carbon dioxide (CO2) from the atmosphere and releasing it back into the atmosphere at different stages of the process.
1. It removes CO2 from the atmosphere during glycolysis:
Glycolysis is the initial step of cellular respiration, which occurs in the cytoplasm of cells. During glycolysis, glucose is broken down into pyruvate molecules, resulting in the production of a small amount of ATP and NADH. This step does not directly remove CO2 from the atmosphere.
2. It removes CO2 from the atmosphere during the citric acid cycle (also known as the Krebs cycle or TCA cycle):
The citric acid cycle takes place in the mitochondria of cells. During this cycle, pyruvate is further broken down, releasing CO2 as a byproduct. The CO2 is then released into the atmosphere.
3. It releases CO2 to the atmosphere during acetyl CoA formation:
Prior to entering the citric acid cycle, pyruvate molecules are converted into acetyl CoA. This conversion results in the release of one molecule of CO2 for each pyruvate molecule.
4. It releases CO2 to the atmosphere during electron transport:
The final stage of cellular respiration is the electron transport chain, which occurs in the inner mitochondrial membrane. As electrons are transferred along the chain, ATP is produced, and oxygen (O2) acts as an electron acceptor. The combination of electrons and oxygen results in the release of water (H2O). However, in this process, some electrons may interact with molecular oxygen to form superoxide anions (O2-), which can subsequently react with protons (H+) to form water and release CO2 as a byproduct.
In summary, cellular respiration removes CO2 from the atmosphere during the citric acid cycle and releases CO2 back into the atmosphere during both acetyl-CoA formation and electron transport.