During cellular respiration, glucose (C₆H₁₂O₆) is broken down in the presence of oxygen (O₂) to produce carbon dioxide (CO₂), water (H₂O), and ATP (adenosine triphosphate). This process takes place in the mitochondria of cells and can be summarized by the chemical equation:
[tex]\[ C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP} \][/tex]
Here is a detailed step-by-step explanation of what occurs during cellular respiration and how energy transfer happens:
1. Glycolysis: This is the first step of cellular respiration, occurring in the cytoplasm. One glucose molecule is broken down into two molecules of pyruvate. During this process, a small amount of ATP is produced, and electron carriers like NADH capture some energy.
2. Pyruvate Oxidation: The pyruvate molecules move into the mitochondria, where they are converted into Acetyl CoA. This step produces carbon dioxide and additional NADH, which carries energy.
3. Citric Acid Cycle (Krebs Cycle): Acetyl CoA enters the citric acid cycle, which takes place in the mitochondrial matrix. This cycle processes the Acetyl CoA and generates more carbon dioxide, ATP, NADH, and FADH₂ (another electron carrier).
4. Electron Transport Chain and Oxidative Phosphorylation: This is the final stage, occurring in the inner mitochondrial membrane. The electron carriers NADH and FADH₂ donate electrons to the electron transport chain, which moves electrons through a series of proteins. This movement of electrons generates a proton gradient that drives the synthesis of a larger amount of ATP through chemiosmosis.
Throughout these stages, the energy stored in the bonds of glucose is carefully transferred to form ATP. ATP acts as the primary energy currency of the cell, powering various biological processes. Thus, the energy from glucose is transferred to ATP.
Therefore, the correct answer is:
- The energy is transferred to ATP.
The choice corresponding to this correct answer is:
4. The energy is transferred to ATP.
