1. What is the primary function of the liver in detoxification?
A) Absorption of nutrients
B) Synthesis of bile
C) Breakdown of toxins
D) Regulation of blood sugar
Answer: C) Breakdown of toxins
Explanation: The liver plays a critical role in detoxifying the blood by breaking down harmful substances such as alcohol, drugs, and metabolic waste products.
2. Which substance is detoxified by the liver?
A) Oxygen
B) Urea
C) Carbon dioxide
D) Glucose
Answer: B) Urea
Explanation: The liver converts ammonia, a toxic by-product of protein metabolism, into urea, which is then excreted by the kidneys.
3. What enzyme is involved in the liver’s detoxification process?
A) Amylase
B) Cytochrome P450
C) Lipase
D) Pepsin
Answer: B) Cytochrome P450
Explanation: Cytochrome P450 enzymes are involved in the oxidation of xenobiotics, which include toxins and drugs, facilitating their breakdown and elimination.
4. What is the function of bile produced by the liver?
A) Storage of vitamins
B) Breaking down fats
C) Blood clotting
D) Detoxification of heavy metals
Answer: B) Breaking down fats
Explanation: Bile produced by the liver helps emulsify fats, aiding in their digestion and absorption in the small intestine.
5. How does the liver contribute to glucose regulation?
A) By storing glucose as glycogen
B) By producing glucose from amino acids
C) By releasing insulin
D) By storing glucose as fat
Answer: A) By storing glucose as glycogen
Explanation: The liver stores excess glucose in the form of glycogen and releases it into the bloodstream when blood sugar levels are low.
6. Which of the following is a function of the liver in metabolism?
A) Storing excess triglycerides
B) Synthesizing cholesterol
C) Producing red blood cells
D) Digesting protein
Answer: B) Synthesizing cholesterol
Explanation: The liver is responsible for synthesizing cholesterol, which is essential for cell membrane structure and hormone production.
7. The liver is responsible for metabolizing which of the following?
A) Oxygen
B) Proteins
C) Calcium
D) Nitrogen
Answer: B) Proteins
Explanation: The liver plays a central role in protein metabolism, including synthesizing albumin and clotting factors, and converting ammonia into urea.
8. Which process involves the conversion of ammonia into urea in the liver?
A) Gluconeogenesis
B) Deamination
C) Beta-oxidation
D) Transamination
Answer: B) Deamination
Explanation: Deamination is the process of removing an amino group from amino acids, converting ammonia into urea, which is then excreted by the kidneys.
9. Which vitamin is stored and metabolized in the liver?
A) Vitamin C
B) Vitamin D
C) Vitamin B12
D) Vitamin A
Answer: D) Vitamin A
Explanation: The liver stores fat-soluble vitamins like vitamin A and releases them when needed by the body.
10. Which of the following is a detoxification process performed by the liver?
A) Hydrolysis of starch
B) Glycogenesis
C) Phagocytosis of bacteria
D) Biotransformation of drugs
Answer: D) Biotransformation of drugs
Explanation: The liver metabolizes drugs and other xenobiotics through a series of biochemical reactions, rendering them less harmful and easier to excrete.
11. What is the role of the liver in the metabolism of fats?
A) Production of bile salts
B) Synthesis of proteins
C) Conversion of carbohydrates into fats
D) Breakdown of fatty acids
Answer: A) Production of bile salts
Explanation: The liver produces bile salts that are essential for the digestion and absorption of fats in the small intestine.
12. Which of the following is directly detoxified in the liver?
A) Oxygen
B) Hormones
C) Glucose
D) Proteins
Answer: B) Hormones
Explanation: The liver plays a role in the metabolism and inactivation of hormones, such as insulin and thyroid hormones, to maintain balance in the body.
13. Which of the following compounds does the liver help convert into glucose?
A) Fatty acids
B) Amino acids
C) Urea
D) Glycerol
Answer: B) Amino acids
Explanation: The liver can convert amino acids into glucose through a process called gluconeogenesis, especially during fasting or stress.
14. Which of the following is NOT a function of the liver?
A) Production of insulin
B) Detoxification of blood
C) Synthesis of proteins
D) Storage of glycogen
Answer: A) Production of insulin
Explanation: The liver does not produce insulin; this hormone is produced by the pancreas. However, the liver helps regulate blood glucose levels.
15. The liver’s role in detoxification includes breaking down which of the following?
A) Vitamins
B) Drugs and alcohol
C) Carbohydrates
D) Proteins
Answer: B) Drugs and alcohol
Explanation: The liver detoxifies harmful substances such as alcohol, drugs, and metabolic waste products to protect the body.
16. What does the liver convert excess carbohydrates into for storage?
A) Glucose
B) Glycogen
C) Triglycerides
D) Amino acids
Answer: B) Glycogen
Explanation: The liver stores excess glucose as glycogen, which can later be converted back into glucose when the body needs it.
17. How does the liver contribute to lipid metabolism?
A) By synthesizing lipoproteins
B) By storing triglycerides
C) By producing bile
D) By metabolizing carbohydrates
Answer: A) By synthesizing lipoproteins
Explanation: The liver synthesizes lipoproteins, such as VLDL and LDL, which are essential for transporting lipids through the bloodstream.
18. What is the relationship between the liver and blood clotting?
A) The liver synthesizes clotting factors
B) The liver breaks down clotting factors
C) The liver produces red blood cells
D) The liver removes blood clots
Answer: A) The liver synthesizes clotting factors
Explanation: The liver is responsible for synthesizing several proteins that are necessary for blood clotting, including fibrinogen and prothrombin.
19. Which of the following does the liver synthesize from amino acids?
A) Urea
B) Glucose
C) Fatty acids
D) Proteins
Answer: D) Proteins
Explanation: The liver synthesizes a variety of proteins, including plasma proteins such as albumin and clotting factors, from amino acids.
20. What is the primary waste product produced during the detoxification process in the liver?
A) Bile
B) Urea
C) Ammonia
D) Lactic acid
Answer: B) Urea
Explanation: The liver converts ammonia, a toxic by-product of protein metabolism, into urea, which is then excreted by the kidneys.
21. The liver metabolizes which type of macromolecule?
A) Carbohydrates
B) Proteins
C) Lipids
D) All of the above
Answer: D) All of the above
Explanation: The liver is involved in the metabolism of all three macromolecules: carbohydrates (glucose), proteins (amino acids), and lipids (fatty acids).
22. What is a major metabolic function of the liver during fasting?
A) Synthesis of amino acids
B) Storage of vitamins
C) Gluconeogenesis
D) Breakdown of fatty acids
Answer: C) Gluconeogenesis
Explanation: During fasting, the liver produces glucose from non-carbohydrate sources (such as amino acids) to maintain blood sugar levels.
23. What is the role of the liver in cholesterol metabolism?
A) Cholesterol is stored in the liver
B) The liver synthesizes cholesterol
C) The liver breaks down cholesterol
D) The liver excretes cholesterol as bile
Answer: B) The liver synthesizes cholesterol
Explanation: The liver plays a central role in cholesterol metabolism by synthesizing cholesterol, which is vital for cell membranes and hormone production.
24. Which of the following toxins is processed by the liver?
A) Carbon dioxide
B) Alcohol
C) Oxygen
D) Nitrogen
Answer: B) Alcohol
Explanation: The liver detoxifies alcohol through enzymatic reactions, converting it into acetaldehyde and then acetic acid.
25. What is the effect of liver failure on detoxification?
A) Reduced bile production
B) Accumulation of toxins in the blood
C) Increased insulin sensitivity
D) Decreased vitamin A storage
Answer: B) Accumulation of toxins in the blood
Explanation: Liver failure impairs detoxification, leading to the accumulation of toxins such as ammonia, which can cause serious health problems.
26. Which of the following is a by-product of protein metabolism detoxified by the liver?
A) Ketone bodies
B) Ammonia
C) Lactate
D) Acetyl-CoA
Answer: B) Ammonia
Explanation: Ammonia is a toxic by-product of protein metabolism that the liver converts into less toxic urea for excretion.
27. The liver is responsible for producing which of the following?
A) Platelets
B) Insulin
C) Red blood cells
D) Albumin
Answer: D) Albumin
Explanation: The liver produces albumin, a protein that helps maintain blood volume and pressure by preventing fluid from leaking into tissues.
28. Which of the following is a function of bile produced by the liver?
A) Storing glucose
B) Emulsifying fats
C) Filtering toxins
D) Breaking down proteins
Answer: B) Emulsifying fats
Explanation: Bile produced by the liver emulsifies fats in the digestive system, making them easier to digest and absorb.
29. Which condition is caused by the liver’s inability to metabolize bilirubin properly?
A) Hepatitis
B) Jaundice
C) Cirrhosis
D) Fatty liver disease
Answer: B) Jaundice
Explanation: Jaundice occurs when the liver cannot properly process bilirubin, leading to its buildup in the blood and causing yellowing of the skin and eyes.
30. Which of the following is NOT a function of the liver?
A) Detoxifying harmful substances
B) Regulating blood sugar levels
C) Storing red blood cells
D) Producing bile
Answer: C) Storing red blood cells
Explanation: The liver does not store red blood cells; this function is carried out by the spleen. The liver is involved in various metabolic and detoxification processes.
These MCQs provide a comprehensive understanding of the liver’s role in detoxification and metabolism.
