Note Summary for Lecture on Cellular Respiration and Photosynthesis

Introduction

• Cellular Respiration and Photosynthesis are two fundamental biochemical processes in biology.
• They are crucial for the energy transformation and sustaining life.

Cellular Respiration

• Defined as the process by which cells convert glucose and oxygen into energy (ATP), carbon dioxide, and water.
• Stages of Cellular Respiration:
  • Glycolysis
    • Occurs in the cytoplasm.
    • Converts glucose into pyruvate.
    • Produces a small amount of ATP and NADH.
  • Krebs Cycle (Citric Acid Cycle)
    • Takes place in the mitochondria.
    • Pyruvate is further broken down.
    • Produces CO2, ATP, NADH, and FADH2.
  • Electron Transport Chain (ETC)
    • Located in the inner mitochondrial membrane.
    • Uses NADH and FADH2 to create a proton gradient.
    • Produces a significant amount of ATP via oxidative phosphorylation.

Photosynthesis

• The process by which green plants, algae, and some bacteria convert light energy, water, and carbon dioxide into glucose and oxygen.
• Two Main Phases of Photosynthesis:
  • Light-dependent Reactions
    • Occur in the thylakoid membranes of chloroplasts.
    • Use light energy to produce ATP and NADPH.
    • Oxygen is released as a byproduct.
  • Calvin Cycle (Light-independent Reactions)
    • Occurs in the stroma of chloroplasts.
    • Uses ATP and NADPH to convert CO2 into glucose.

Importance in Ecology

• Interdependence of Photosynthesis and Cellular Respiration:
  • Photosynthesis provides the oxygen and organic compounds used in cellular respiration.
  • Cellular respiration releases CO2, which is used in photosynthesis.
• Crucial for maintaining atmospheric oxygen and carbon dioxide balance.

Conclusion

• Both processes are essential for energy flow in ecosystems.
• Understanding these processes is key to grasping biological energy conversion and ecological balance.