What are the reactants and products of cellular respiration
The Correct Answer and Explanation is:
Correct Answer:
- Reactants of Cellular Respiration:
- Glucose (C₆H₁₂O₆)
- Oxygen (O₂)
- Products of Cellular Respiration:
- Carbon dioxide (CO₂)
- Water (H₂O)
- Energy (in the form of ATP)
Explanation
Cellular respiration is a biochemical process by which cells convert glucose and oxygen into usable energy. This process occurs in almost all living organisms, particularly in the mitochondria of eukaryotic cells. The overall balanced chemical equation for aerobic cellular respiration is:
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP (energy)
This equation shows that one molecule of glucose reacts with six molecules of oxygen to produce six molecules of carbon dioxide, six molecules of water, and a significant amount of ATP, the energy currency of the cell.
The process takes place in three main stages:
- Glycolysis (in the cytoplasm): This first stage breaks down one glucose molecule into two molecules of pyruvate, generating a small amount of ATP and NADH (an electron carrier). It does not require oxygen and occurs in both aerobic and anaerobic respiration.
- Krebs Cycle (in the mitochondrial matrix): The pyruvate is further broken down, releasing carbon dioxide. This stage produces more electron carriers (NADH and FADH₂) and a small amount of ATP.
- Electron Transport Chain (ETC) (in the inner mitochondrial membrane): This is the final and most productive stage. The NADH and FADH₂ donate electrons, which move through protein complexes. Oxygen acts as the final electron acceptor and combines with hydrogen to form water. Most of the ATP (up to 34 molecules) is produced during this step.
The primary purpose of cellular respiration is to generate ATP, which powers cellular activities like muscle contraction, active transport, and biosynthesis. Without oxygen (in anaerobic respiration), the process yields much less ATP. In summary, glucose and oxygen are vital inputs for the efficient energy production that sustains life.
