⚡️8. Pentose Phosphate Pathway

• What is the primary product of glycolysis from carbohydrates?

  Pyruvic acid
• What is the pentose phosphate pathway responsible for?

  Breaking down glucose for energy
• What percentage of glucose breakdown in the liver is due to the pentose phosphate pathway?

  30 percent
• Why is the pentose phosphate pathway important?

  It provides energy independently of the citric acid cycle
• How does the pentose phosphate pathway differ from glycolysis in terms of energy production?

  It does not rely on glycolytic enzymes
• What molecule is formed from glucose in the pentose phosphate pathway?

  D-ribulose
• How many molecules of glucose are resynthesized for every six molecules that enter the pentose phosphate pathway?

  Five molecules
• What happens to hydrogen released during the pentose phosphate pathway?

  It combines with NADP+ to form NADPH
• Why is NADPH significant in the synthesis of fats?

  It is required for fat synthesis from carbohydrates
• What happens to excess glucose when glycogen stores are full?

  It is converted into fat
• What is gluconeogenesis?

  Formation of glucose from non-carbohydrate sources
• Why is gluconeogenesis important during fasting?

  It prevents excessive reduction in blood glucose
• What percentage of the liver's glucose production during fasting comes from gluconeogenesis?

  25 percent
• Which organ plays a key role in maintaining blood glucose levels during fasting?

  The liver
• How do amino acids contribute to gluconeogenesis?

  They provide substrates for glucose synthesis
• What is the normal blood glucose concentration after fasting for 3 to 4 hours?

  About 90 mg/dl
• What happens to blood glucose levels after a carbohydrate-rich meal?

  It seldom rises above 140 mg/dl
• How are insulin and glucagon related to blood glucose regulation?

  They regulate blood glucose concentration
• What are the main processes involved in glucose metabolism?

  • Glycolysis: Converts glucose to pyruvic acid
  • Pentose phosphate pathway: Breaks down glucose for energy
  • Gluconeogenesis: Forms glucose from non-carbohydrate sources
  • Glycogenolysis: Converts glycogen to glucose
• What are the roles of NADP+ and NAD+ in glucose metabolism?

  • NAD+: Used in glycolysis for ATP production
  • NADP+: Used in pentose phosphate pathway for fat synthesis
• What happens to glucose when glycogen stores are full?

  • Converted into fat
  • Stored in fat cells
• What stimulates gluconeogenesis?

  • Diminished carbohydrates in cells
  • Decreased blood sugar levels
  • Hormone cortisol release