process by which energy is produced when oxygen burns up food through the body? (9)
The process by which energy is produced when oxygen burns up food through the body is called cellular respiration. Cellular respiration occurs in the mitochondria of cells and involves a series of biochemical reactions that convert glucose and oxygen into carbon dioxide, water, and adenosine triphosphate (ATP). ATP is a molecule that serves as the main energy currency of the cell.
To understand this process in more detail, consider the following steps:
1. Glycolysis: This is the initial step of cellular respiration that occurs in the cytoplasm. Glucose, a sugar molecule, is broken down into two molecules of pyruvate, producing a small amount of ATP.
2. Pyruvate Decarboxylation: In this step, each pyruvate molecule enters the mitochondria and undergoes decarboxylation, resulting in the formation of acetyl-CoA.
3. Citric Acid Cycle (Krebs cycle): Acetyl-CoA enters the citric acid cycle, which takes place in the mitochondria. Through a series of enzymatic reactions, acetyl-CoA is further broken down, releasing carbon dioxide and generating additional ATP and electron carriers, such as NADH and FADH2.
4. Electron Transport Chain (ETC): NADH and FADH2 from the previous steps donate their electrons to the electron transport chain, which is located in the inner mitochondrial membrane. As the electrons move through the chain, energy is released and used to pump protons across the membrane, creating an electrochemical gradient.
5. ATP Synthesis: The protons that were pumped across the membrane during the electron transport chain flow back into the matrix of the mitochondria through an enzyme called ATP synthase. This flow of protons drives the synthesis of ATP from adenosine diphosphate (ADP) and inorganic phosphate.
Overall, cellular respiration produces a large amount of ATP, which is utilized by the cells for various functions, including muscle contraction, cellular communication, and maintaining vital processes.
It's important to note that while oxygen is essential for the complete breakdown of glucose and the synthesis of ATP, certain cells in the body can perform anaerobic respiration, which generates a limited amount of ATP in the absence of oxygen. However, anaerobic respiration results in the buildup of lactic acid or other byproducts, leading to fatigue and the potential for tissue damage.