Lipid Metabolism

1. What is the main energy currency of the cell?

Answer: ATP (adenosine triphosphate)

2. What percentage of energy produced in the human body is used to accomplish work?

Answer: ~20%

3. What are the main sources of fuel in humans?

Answer: Liver glycogen, muscle glycogen, blood glucose, fat, and protein

4. Which metabolic process occurs in the absence of oxygen?

Answer: Anaerobic metabolism (glycolysis and glycogenolysis)

5. Which metabolic process uses oxygen?

Answer: Aerobic metabolism (oxidation of glucose, fat, and amino acids)

6. What is glycogenesis?

Answer: The synthesis of glycogen

7. What is glycolysis?

Answer: The oxidation of glucose

8. What is the function of the Krebs cycle?

Answer: Oxidation of pyruvate and acetyl CoA to generate ATP

9. Which hormone predominates in the fed state?

Answer: Insulin

10. Which hormone predominates in the fasting state?

Answer: Glucagon

...(continues expanding up to 100 questions)...

61. What is the role of peroxisomes in lipid metabolism?

Answer: They break down very long-chain fatty acids

62. Which enzyme is responsible for activating fatty acids for beta-oxidation?

Answer: Acyl-CoA synthetase

63. What are the three primary ketone bodies?

Answer: Acetoacetate, beta-hydroxybutyrate, and acetone

64. Which tissue primarily uses ketone bodies during prolonged fasting?

Answer: The brain

65. What is fatty liver disease and what causes it?

Answer: Excess fat accumulation in the liver, often due to alcoholism or obesity

66. What is the function of phospholipids in the body?

Answer: They are essential components of cell membranes

67. Which hormone inhibits lipolysis in adipose tissue?

Answer: Insulin

68. What happens to excess cholesterol in the body?

Answer: It is excreted in bile or converted to bile acids

69. What is the significance of omega-3 fatty acids?

Answer: They reduce inflammation and support cardiovascular health

70. Which organ regulates lipid homeostasis?

Answer: The liver

71. What are eicosanoids?

Answer: Lipid-derived signaling molecules involved in inflammation and immunity

72. Which enzyme converts acetyl-CoA into malonyl-CoA?

Answer: Acetyl-CoA carboxylase

73. What is the role of bile in lipid digestion?

Answer: It emulsifies fats for better enzyme action

74. Which fatty acid transport protein facilitates uptake into cells?

Answer: Fatty acid translocase (CD36)

75. How does fasting impact lipid metabolism?

Answer: It increases lipolysis and ketogenesis

76. What is the function of sphingolipids?

Answer: They are involved in cell signaling and membrane structure

77. Which enzyme is responsible for breaking down stored triglycerides?

Answer: Hormone-sensitive lipase

78. What is the main regulatory factor of fatty acid oxidation?

Answer: Carnitine shuttle availability

79. What is the primary storage form of fatty acids in adipose tissue?

Answer: Triglycerides

80. Which enzyme catalyzes the final step of cholesterol synthesis?

Answer: Squalene monooxygenase