Cellular Respiration Processes and Pathways

Metabolic Pathways

• Catabolic pathways break down complex molecules into simpler compounds, releasing energy in the process.
• Anabolic pathways synthesize larger molecules from smaller ones, consuming energy to do so.

Oxidation-Reduction Reactions

• Oxidation-reduction, or redox reactions, involve the transfer of electrons between atoms or ions.
• In a redox reaction, one atom or ion loses electrons while another gains them.

Oxidation of Molecules

• Oxidation refers to the process of losing electrons from a molecule.

Cellular Respiration Location

• Respiration occurs in the mitochondria, the powerhouse of the cell.

Steps of Aerobic Cellular Respiration

• Three main steps: Glycolysis, Krebs Cycle, and the Electron Transport Chain (ETC).

Locations of Respiration Steps

• Glycolysis occurs in the cytosol (cytoplasm) of the cell.
• The Krebs Cycle and Electron Transport Chain take place within the mitochondria.

ATP Production

• The majority of ATP is produced during the Electron Transport Chain.

Phosphorylation Types

• Substrate-level phosphorylation generates ATP through the direct transfer of a phosphate group.
• Oxidative phosphorylation produces ATP via the energy produced from electron transport.

Glycolysis Reactants and Products

• Reactants: 1 molecule of glucose, 2 NAD+, and 2 ATP.
• Products: 2 molecules of pyruvic acid, 2 NADH, and 4 ATP.

Krebs Cycle Reactants and Products

• Reactants: 2 molecules of pyruvic acid derived from glycolysis.
• Products: 2 ATP, 6 NADH, 2 FADH2, and 4 CO2.

Electron Transport Chain (ETC) Reactants and Products

• Reactants: Oxygen and ADP.
• Products: ATP, oxidized NAD+ ions, and water (H2O).

Role of Phosphorylation

• A phosphorylated molecule can alter protein function by changing its shape, leading to activation or deactivation.

Importance of Oxygen

• Oxygen serves as the final electron acceptor in cellular respiration, essential for effective energy production.

ATP Synthase Function

• ATP synthase is an enzyme responsible for synthesizing ATP from ADP utilizing energy from proton gradients.
• It plays a crucial role by linking to the electron transport system through the proton-motive force, facilitating the influx of protons into mitochondria.