3.2 Aerobic Respiration - Overview

3.2 Aerobic Respiration Overview

Cellular Respiration

  • Definition: Catabolic pathway that breaks down energy-rich compounds to produce ATP.

  • Location: Occurs in both plant and animal cells.

Two Types of Cellular Respiration

  • Aerobic Respiration:

    • Requires oxygen.

    • Involves complete oxidation of glucose.

  • Anaerobic Respiration:

    • Occurs in the absence of oxygen.

    • Less efficient in energy production compared to aerobic respiration.

ATP Production Methods During Cellular Respiration

Substrate Level Phosphorylation

  • Definition: ATP formation from the transfer of a phosphate group from a substrate (molecule) to ADP.

  • Occurs In:

    • Glycolysis

    • Krebs Cycle

Oxidative Phosphorylation

  • Definition: A process that couples the oxidation of NADH and FADH2 by the electron transport chain.

  • Mechanism: Produces a proton gradient that powers ATP formation.

  • Occurs In:

    • Electron Transport Chain (Oxidative Phosphorylation and Chemiosmosis)

Overall Equation for Cellular Respiration

  • Chemical Equation:C6H12O6 (s) + 6O2 (g) → 6CO2 (g) + 6H2O (l) + 36 ATP

  • Referred to as a REDOX reaction.

Structure of the Mitochondria

  • Outer Membrane: Surrounds the mitochondrion.

  • Inner Membrane: Contains the proteins for the electron transport chain.

  • Intermembrane Space: Space between the outer and inner membranes.

  • Cristae: Folded inner membrane where ATP synthesis occurs.

  • Matrix: Contains enzymes for the Krebs cycle and mitochondrial DNA.

Stages of Cellular Respiration

  1. Glycolysis:

    • Occurs in the cytosol.

  2. Pyruvate Oxidation:

    • Occurs in the mitochondrial matrix.

  3. Krebs Cycle:

    • Occurs in the mitochondrial matrix.

  4. Electron Transport Chain (ETC)/Chemiosmosis:

    • Occurs across the inner mitochondrial membrane.

Additional Insights

  • Electron Transport:

    • Electrons carried via NADH and FADH2.

    • Leading to production of water and ATP.

Typical Energy Yield

  • Total ATP Yield:

    • Usually around 36 ATP per molecule of glucose.