Miss Angler's Biology Class - Anaerobic Respiration

Introduction

• Focus on anaerobic respiration.
• Pre-requisite: Watch aerobic respiration videos, especially glycolysis.
• For Grade 11 students: Cheat sheet study guide available.

Definition of Anaerobic Respiration

• Anaerobic: Without oxygen.
• Glycolysis: Anaerobic process, no oxygen required.
• Transition to anaerobic respiration occurs if no oxygen is present post-glycolysis.

Glycolysis Recap

• Breakdown of glucose to make hydrogens usable and form pyruvate.
• If oxygen present: progresses to Krebs Cycle.
• No oxygen: proceeds to fermentation.

Types of Fermentation

1. Alcoholic Fermentation

   • Occurs in plants and yeast.
   • Process Overview:
     • Begins with glycolysis, ends with pyruvate.
     • Glucose breakdown produces 2 ATPs and NADH.
     • Pyruvate loses oxygen, forms acetal, and ultimately 2 ethanol molecules.
   • Byproducts: Ethanol, carbon dioxide.

2. Lactic Acid Fermentation

   • Occurs in animals.
   • Reason: Oxygen debt (e.g., during intense exercise).
   • Process Overview:
     • Same glycolysis pathway to pyruvate.
     • Produces 2 lactic acid molecules instead of ethanol.
   • Byproducts: Lactic acid.

Key Concepts

• Phosphorylation: Adding a phosphate ion to ADP to form ATP.
• Hydrogen Ions: Energized ions crucial for energy transformation.

Examination Tips

• Understand the summary of reactions: reactants and byproducts.
• Common exam format involves investigations or diagrams.

Investigative Example

• Setup: Two test tubes—one with glucose and yeast, another with lime water.
• Key Observations:
  • Yeast indicates alcoholic fermentation.
  • Lime water turns milky in presence of carbon dioxide (indicates fermentation).
  • Importance of boiling to exclude other microorganisms.
  • Thin oil layer and rubber stopper prevent oxygen entry.

Terminology Recap

• Glycolysis: Anaerobic conversion of glucose to pyruvate.
• Types of Fermentation:
  • Lactic Acid (Animals)
  • Alcoholic (Yeast and Plants)
• Key Byproduct: Carbon dioxide tested with lime water.

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