Bioenergetics: Oxidative Phosphorylation and Energy Metabolism

Bioenergetics

Oxidative Phosphorylation

• Process by which cells generate energy in the form of ATP
• Occurs in the mitochondria
• Involves the transfer of electrons from high-energy molecules to oxygen, resulting in the formation of ATP
• Consists of three stages: electron transport, proton pumping, and ATP synthesis
• Net yield of 36-38 ATP molecules per glucose molecule

Energy Metabolism

• Process by which cells convert energy from one form to another
• Involves the breakdown of nutrients (e.g. glucose, fats) to produce ATP
• ATP is the primary energy currency of the cell
• Energy metabolism is regulated by hormones, enzymes, and other molecules

Cellular Respiration

• Process by which cells generate energy from glucose
• Consists of three stages: glycolysis, citric acid cycle, and oxidative phosphorylation
• Glycolysis: breakdown of glucose to pyruvate, resulting in 2 ATP and 2 NADH
• Citric acid cycle: breakdown of pyruvate to acetyl-CoA, resulting in 2 ATP, 6 NADH, and 2 FADH2
• Oxidative phosphorylation: generation of ATP from NADH and FADH2

ATP Synthesis

• Process by which ATP is generated from ADP and Pi
• Occurs during oxidative phosphorylation
• Involves the movement of protons across the mitochondrial membrane, driving the production of ATP
• ATP synthase: enzyme responsible for ATP synthesis

Mitochondrial Function

• Mitochondria: organelles responsible for generating energy for the cell
• Functions:
  • Generate ATP through oxidative phosphorylation
  • Regulate cellular metabolism
  • Maintain cellular redox balance
  • Initiate apoptosis (programmed cell death)
• Mitochondrial dysfunction: implicated in various diseases, including neurodegenerative disorders and cancer

Bioenergetics

Oxidative Phosphorylation

• Generates energy in the form of ATP through electron transport, proton pumping, and ATP synthesis
• Occurs in the mitochondrial inner membrane
• Produces 36-38 ATP molecules per glucose molecule
• Involves the transfer of electrons from high-energy molecules to oxygen

Energy Metabolism

• Converts energy from one form to another through the breakdown of nutrients
• ATP is the primary energy currency of the cell
• Regulated by hormones, enzymes, and other molecules
• Involves the breakdown of glucose, fats, and other nutrients

Cellular Respiration

• Generates energy from glucose through three stages: glycolysis, citric acid cycle, and oxidative phosphorylation
• Glycolysis produces 2 ATP and 2 NADH
• Citric acid cycle produces 2 ATP, 6 NADH, and 2 FADH2
• Oxidative phosphorylation generates ATP from NADH and FADH2

ATP Synthesis

• Generates ATP from ADP and Pi during oxidative phosphorylation
• Driven by the movement of protons across the mitochondrial membrane
• ATP synthase is the enzyme responsible for ATP synthesis

Mitochondrial Function

• Mitochondria generate energy for the cell through oxidative phosphorylation
• Regulate cellular metabolism and maintain cellular redox balance
• Initiate apoptosis (programmed cell death) in response to cellular stress
• Mitochondrial dysfunction is implicated in neurodegenerative disorders and cancer