Which of the following is correct pathway of glucose breakdown during aerobic respiration?

The correct answer is Glucose → Pyruvic acid → CO₂ + Water.

Key Points

• Aerobic respiration involves the complete breakdown of glucose in the presence of oxygen.
• The pathway of glucose breakdown starts with glycolysis, where glucose is converted into pyruvic acid.
• In the presence of oxygen, pyruvic acid enters the mitochondria and undergoes further breakdown to form CO₂ and water, releasing energy in the process.
• This energy is used to produce ATP, the main energy currency of cells, through the electron transport chain and oxidative phosphorylation.

Additional Information

• Aerobic Respiration:
  • Aerobic respiration is a type of cellular respiration that occurs in the presence of oxygen.
  • It consists of three main stages: Glycolysis, the Citric Acid Cycle (Krebs Cycle), and the Electron Transport Chain (ETC).
• Glycolysis:
  • Glycolysis is the first step in glucose metabolism and occurs in the cytoplasm of the cell.
  • It breaks down one molecule of glucose (6-carbon) into two molecules of pyruvate (3-carbon), producing 2 ATP and 2 NADH molecules.
• Citric Acid Cycle (Krebs Cycle):
  • Pyruvic acid produced from glycolysis is converted into acetyl-CoA, which enters the citric acid cycle.
  • Through a series of reactions, CO₂ is released, and electrons are transferred to NADH and FADH2.
• Electron Transport Chain:
  • The final stage of aerobic respiration takes place in the mitochondria, where electrons from NADH and FADH2 are transferred through protein complexes.
  • This creates a proton gradient that drives the synthesis of ATP and the reduction of oxygen to form water.