Overview of Aerobic Respiration

Importance of Learning Equations

• Word Equation: Crucial for exams, learn both word and balanced equations.

Stages of Aerobic Respiration

• Two-Stage Process:
  • Stage One: Glycolysis
  • Stage Two: Krebs Cycle and Electron Transport Chain

Stage One: Glycolysis

• Location: Cytosol of the cell (liquid part of the cytoplasm).
• Role of Oxygen: Not involved in glycolysis.
• Process:
  • Starts with glucose (6-carbon molecule).
  • Ends with two 3-carbon molecules of pyruvic acid.
  • Involves removal of hydrogen atoms, forming NADH.
• Energy Production: Net gain of 2 ATP.

Stage Two: Krebs Cycle and Electron Transport Chain

• Location: Mitochondria (the cell's powerhouse).

Krebs Cycle (Citric Acid Cycle)

• Initial Step:
  • Pyruvic acid (3-carbon) converts to Acetyl CoA (2-carbon) by removing CO2 and hydrogen.
  • Hydrogen forms NADH.
• Cycle Process:
  • Acetyl CoA (2-carbon) joins with a 4-carbon molecule to form a 6-carbon molecule.
  • This 6-carbon molecule is broken down back to a 4-carbon molecule, releasing CO2 and hydrogen.
  • Formation of NADH is critical as it contains electrons and protons.
• Outputs:
  • 3 NADH molecules, 1 ATP, and 2 CO2 molecules.
  • Acetyl CoA eventually converts to water and CO2.

Electron Transport Chain

• Process:
  • NADH transfers electrons and protons to the chain.
  • Electrons pass through a series of molecules, releasing energy used to form ATP.
  • Low energy electrons combine with protons and oxygen to form water.
• NADH Role: Reverts to NAD+ after transferring electrons and protons.

Study Tips

• Review and Practice:
  • Understand both stages thoroughly.
  • Practice using exam questions and textbooks.
  • Use video pauses to test knowledge on stages before moving to the next.

Conclusion

• Mastery of these stages and equations is key to understanding aerobic respiration and performing well in exams.