Bioenergetics Notes

Bioenergetics

  • Bioenergetics explains how muscle contraction occurs.
  • It involves converting energy from food into usable energy.
  • Chemical energy is transformed into mechanical energy.

Biochemical Pathways for ATP Generation

  1. Anaerobic Metabolism:
    • Phosphocreatine + ADP → ATP
  2. Anaerobic Metabolism:
    • Glycolysis: Glucose → ATP
  3. Aerobic Metabolism:
    • CHO (Carbohydrates), Fat, or Protein → ATP

Bioenergetics Outline

  • High Energy Phosphates
  • Anaerobic ATP Production
    • ATP-PC system (Phosphocreatine system)
    • Glycolysis
  • Aerobic ATP Production
    • CHO Metabolism
    • Fat Metabolism
    • Protein Metabolism
    • The relationship between metabolism of proteins, CHOs, and Fats
    • Kreb’s cycle
    • Electron Transport Chain
    • ATP Tally

High Energy Phosphates

  • ATP structure
  • ATP synthesis
  • ATP degradation

Anaerobic ATP Production

  • ATP-PC system
    • Rate limiting factors
    • Creatine Supplementation
  • Glycolysis
    • Formation of pyruvate from either glucose or glycogen
    • Reconversion of NAD
      • Lactate dehydrogenase
      • Glycerol-3-phosphate shuttle
      • Malate-aspartate shuttle
    • Rate limiting factors

Adenosine Triphosphate (ATP)

  • Consists of adenine, ribose, and three linked phosphates

ATP Synthesis and Degradation

  • ATP Synthesis: ADP+Pi+Energy→ATPADP + P_i + Energy \rightarrow ATP
  • ATP Degradation/Breakdown: ATP→ADP+Pi+EnergyATP \rightarrow ADP + P_i + Energy
  • Enzyme involved in ATP breakdown: ATPase

Anaerobic Metabolism

  • Does not involve O2O_2 in ATP generation.
    1. PC (phosphocreatine or creatine phosphate) breakdown
    2. Glycolysis from glucose or glycogen

Anaerobic ATP Production - ATP-PC System

  • Immediate source of ATP.
  • Occurs within the cytosol.
  • Involves a single enzyme: Creatine Kinase.
  • Process: Phosphorylation.
  • Phosphocreatine + ADP ↔\leftrightarrow Creatine + ATP + Energy

Control (Rate limiting factor) of ATP-PC system

  • Rate-Limiting Enzyme: Creatine kinase
  • Stimulators: ADP
  • Inhibitors: ATP

Creatine Supplementation

  • How could creatine supplementation benefit the ATP-PC system?
  • What duration of performance could possibly benefit from creatine supplementation?

Creatine Supplementation and Phosphocreatine Formation

  • Creatine + Pi requires energy to form phosphocreatine
  • It takes energy to form phosphocreatine

Anaerobic ATP Production - Glycolysis

  • When PC and CK are depleted, glycolysis is activated for ATP production.
  • Simple Version: Glucose →\rightarrow acetyl CoA →\rightarrow ATP or Lactate.

Glycolysis

  • A metabolic pathway that converts glucose into pyruvate.

Glycolysis Details

  • Inputs:
    • 1 glucose
    • 2 ADP
    • 2 NAD+
  • Outputs:
    • 2 pyruvate or 2 lactate
    • 2 ATP (Net production: 2 ATP, 4 ATP produced - 2 ATP required)
    • 2 NADH

Glycolysis Location

  • Occurs in the cytosol.
  • Pyruvate is a