Carbohydrate Metabolism Overview

Carbohydrate Metabolism Overview

• Carbohydrate metabolism is the process by which cells convert carbohydrates into energy or other molecules
• It involves the breakdown (catabolism) and synthesis (anabolism) of carbohydrates, such as glucose, glycogen, and starch

Carbohydrate Catabolism

• Glycolysis: breakdown of glucose into pyruvate, producing ATP and NADH
  • Takes place in the cytosol
  • Net gain of 2 ATP and 2 NADH
• Pyruvate Oxidation: conversion of pyruvate into acetyl-CoA, which enters the citric acid cycle
  • Takes place in the mitochondria
  • Produces NADH and FADH2
• Citric Acid Cycle (Krebs Cycle): breakdown of acetyl-CoA into carbon dioxide, producing ATP, NADH, and FADH2
  • Takes place in the mitochondria
  • Net gain of 2 ATP, 6 NADH, and 2 FADH2
• Electron Transport Chain: transfer of electrons from NADH and FADH2 to oxygen, producing ATP
  • Takes place in the mitochondrial inner membrane
  • Net gain of 32-34 ATP

Carbohydrate Anabolism

• Glycogen Synthesis: conversion of glucose into glycogen, a stored form of energy
  • Takes place in the liver and muscles
  • Regulated by insulin and glucagon
• Gluconeogenesis: synthesis of glucose from non-carbohydrate sources, such as amino acids and lactate
  • Takes place in the liver and kidneys
  • Regulated by insulin, glucagon, and cortisol

Regulation of Carbohydrate Metabolism

• Insulin: promotes glucose uptake, glycogen synthesis, and glycolysis
• Glucagon: promotes glycogen breakdown, gluconeogenesis, and glucose release
• Hormonal Regulation: other hormones, such as cortisol and epinephrine, also play a role in regulating carbohydrate metabolism
• Feedback Mechanisms: regulation of carbohydrate metabolism through feedback loops, involving ATP, NADH, and other molecules

Carbohydrate Metabolism Overview

• Carbohydrate metabolism is the process of converting carbohydrates into energy or other molecules
• It involves the breakdown (catabolism) and synthesis (anabolism) of carbohydrates, such as glucose, glycogen, and starch

Carbohydrate Catabolism

• Glycolysis is the breakdown of glucose into pyruvate, producing 2 ATP and 2 NADH, and takes place in the cytosol
• Pyruvate oxidation is the conversion of pyruvate into acetyl-CoA, producing NADH and FADH2, and takes place in the mitochondria
• The citric acid cycle (Krebs cycle) is the breakdown of acetyl-CoA into carbon dioxide, producing 2 ATP, 6 NADH, and 2 FADH2, and takes place in the mitochondria
• The electron transport chain is the transfer of electrons from NADH and FADH2 to oxygen, producing 32-34 ATP, and takes place in the mitochondrial inner membrane

Carbohydrate Anabolism

• Glycogen synthesis is the conversion of glucose into glycogen, a stored form of energy, and takes place in the liver and muscles
• Glycogen synthesis is regulated by insulin and glucagon
• Gluconeogenesis is the synthesis of glucose from non-carbohydrate sources, such as amino acids and lactate, and takes place in the liver and kidneys
• Gluconeogenesis is regulated by insulin, glucagon, and cortisol

Regulation of Carbohydrate Metabolism

• Insulin promotes glucose uptake, glycogen synthesis, and glycolysis
• Glucagon promotes glycogen breakdown, gluconeogenesis, and glucose release
• Cortisol and epinephrine also play a role in regulating carbohydrate metabolism
• Feedback mechanisms regulate carbohydrate metabolism through feedback loops involving ATP, NADH, and other molecules