Which are all the correct products of respiration?
O carbon dioxide, water, and glucose
O water and energy
O carbon dioxide, water, and energy
O carbon dioxide and water
The correct answer is: O carbon dioxide, water, and energy.
To understand why, let's break down the process of respiration:
Respiration is a metabolic process that occurs in cells, both in plants and animals, to produce energy. It involves the breakdown of glucose molecules to release energy in the form of ATP (adenosine triphosphate).
During respiration, glucose reacts with oxygen in a series of chemical reactions. The end products of respiration are carbon dioxide, water, and energy. Here's how it happens:
1. Glucose (a simple sugar) is broken down in a series of enzymatic reactions through a process called glycolysis. This process occurs in the cytoplasm of the cell and does not require oxygen. It produces a small amount of ATP and a molecule called pyruvate.
2. If oxygen is available, the pyruvate enters the mitochondria of the cell, where further reactions occur. This is known as aerobic respiration, which produces a significant amount of ATP.
3. In the mitochondria, the pyruvate is converted into a molecule called acetyl-CoA through a process called the Krebs cycle or citric acid cycle. This cycle generates additional ATP and electron-carrying molecules called NADH and FADH2.
4. The acetyl-CoA enters the electron transport chain, where electrons from NADH and FADH2 are passed along a series of protein complexes. This generates a large amount of ATP through a process called oxidative phosphorylation.
5. As electrons are passed through the electron transport chain, oxygen acts as the final electron acceptor, forming water (H2O) as a byproduct.
6. Throughout the entire process, carbon atoms from glucose are progressively broken down and combined with oxygen, resulting in the release of carbon dioxide (CO2).
Hence, carbon dioxide and water are the waste products of respiration, while energy in the form of ATP is the product that is used by cells for various cellular activities.
Therefore, the correct answer is: O carbon dioxide, water, and energy.