Carbohydrate Metabolism and Glycolysis

Carbohydrate Metabolism

Overview

• Carbohydrate metabolism is the process by which cells convert carbohydrates into energy or other molecules
• It involves the breakdown of carbohydrates into glucose, which is then used to produce ATP, NADH, and FADH2

Glycolysis

• Glycolysis is the first stage of carbohydrate metabolism
• It is the breakdown of glucose into pyruvate, producing ATP and NADH
• Takes place in the cytoplasm of cells
• 10 steps, catalyzed by 10 different enzymes

Pyruvate Fate

• Pyruvate can be converted into:
  • Acetyl-CoA (entering the citric acid cycle)
  • Lactate (in anaerobic conditions)
  • Ethanol and CO2 (in yeast fermentation)
  • Oxaloacetate (in the citric acid cycle)

Citric Acid Cycle (Krebs Cycle)

• Also known as the tricarboxylic acid (TCA) cycle or Krebs cycle
• Takes place in the mitochondria
• Acetyl-CoA is converted into ATP, NADH, and FADH2
• 8 steps, catalyzed by 8 different enzymes

Electron Transport Chain

• Takes place in the mitochondrial inner membrane
• Electrons from NADH and FADH2 are passed through a series of protein complexes, generating ATP
• Protons are pumped across the membrane, creating a proton gradient
• ATP synthase uses the proton gradient to produce ATP

Regulation of Carbohydrate Metabolism

• Insulin and glucagon play key roles in regulating carbohydrate metabolism
• Insulin promotes glucose uptake and storage, while glucagon promotes glucose release and breakdown
• Feedback inhibition and allosteric regulation also play important roles in regulating enzyme activity

Carbohydrate Metabolism

• Carbohydrate metabolism is the process by which cells convert carbohydrates into energy or other molecules.

Glycolysis

• Glycolysis is the first stage of carbohydrate metabolism, breaking down glucose into pyruvate.
• It produces ATP and NADH.
• Takes place in the cytoplasm of cells.
• Consists of 10 steps, catalyzed by 10 different enzymes.

Pyruvate Fate

• Pyruvate can be converted into:
  • Acetyl-CoA, entering the citric acid cycle.
  • Lactate, in anaerobic conditions.
  • Ethanol and CO2, in yeast fermentation.
  • Oxaloacetate, in the citric acid cycle.

Citric Acid Cycle (Krebs Cycle)

• Also known as the tricarboxylic acid (TCA) cycle or Krebs cycle.
• Takes place in the mitochondria.
• Acetyl-CoA is converted into ATP, NADH, and FADH2.
• Consists of 8 steps, catalyzed by 8 different enzymes.

Electron Transport Chain

• Takes place in the mitochondrial inner membrane.
• Electrons from NADH and FADH2 are passed through a series of protein complexes, generating ATP.
• Protons are pumped across the membrane, creating a proton gradient.
• ATP synthase uses the proton gradient to produce ATP.

Regulation of Carbohydrate Metabolism

• Insulin and glucagon play key roles in regulating carbohydrate metabolism.
• Insulin promotes glucose uptake and storage.
• Glucagon promotes glucose release and breakdown.
• Feedback inhibition and allosteric regulation also play important roles in regulating enzyme activity.