METABOLISME - BIOLOGI - Kelas 12 (jembatan keledai-cara mudah menghafal)

Introduction

This tutorial provides a comprehensive overview of metabolism, focusing on its two main components: catabolism and anabolism. By breaking down these processes, you will learn how they function in biological systems, including respiration and photosynthesis. This guide is designed to help you understand and memorize these concepts easily.

Step 1: Understanding Catabolism

Catabolism refers to the breakdown of substances to release energy. It primarily encompasses processes like respiration and fermentation.

Key Processes in Catabolism

• Respiration

  1. Glycolysis: The initial step where glucose is broken down into pyruvate, producing a small amount of ATP (energy).
  2. Oxidative Decarboxylation: Pyruvate is converted into Acetyl-CoA, releasing carbon dioxide.
  3. Krebs Cycle: Acetyl-CoA enters this cycle, generating NADH and FADH2, which are crucial for the next step.
  4. Electron Transport Chain: NADH and FADH2 donate electrons to create a proton gradient, producing a large amount of ATP.

• Fermentation

  • Lactic Acid Fermentation: Occurs in muscle cells when oxygen is scarce, converting glucose to lactic acid.
  • Ethanol Fermentation: Used by yeast, converting glucose to ethanol and carbon dioxide.

Practical Tips

• Remember the sequence of respiration by the acronym "G-O-K-E" (Glycolysis, Oxidative Decarboxylation, Krebs Cycle, Electron Transport).
• Consider using flashcards to memorize the steps of fermentation.

Step 2: Understanding Anabolism

Anabolism is the process of building complex molecules from simpler ones, requiring energy input. The most notable example is photosynthesis.

Key Processes in Anabolism

• Photosynthesis

  • Light Reactions (Hill Reaction): Capture solar energy to produce ATP and NADPH.

    • Cyclic Phosphorylation: Electrons travel in a cycle, generating ATP.
    • Non-Cyclic Phosphorylation: Electrons flow through a chain, producing both ATP and NADPH.

  • Calvin Cycle (Dark Reactions): Uses ATP and NADPH to convert carbon dioxide into glucose.

    • Key Molecule: RuBP: Ribulose bisphosphate, which plays a vital role in CO2 fixation.

Practical Tips

• Use diagrams to visualize the light reactions and Calvin cycle for better retention.
• Group related concepts, such as the energy carriers ATP and NADPH, to understand their roles in both catabolism and anabolism.

Conclusion

Understanding metabolism through catabolism and anabolism is essential for grasping biological energy processes. Focus on the key steps of respiration and photosynthesis to solidify your knowledge. Consider exploring related topics through additional resources or videos to enhance your understanding further.