Insulin

PYQ-Based Questions (Q1–10)

1. Insulin is secreted by which organ in the human body? (BPSC 66th Prelims)
   a) Liver
   b) Pancreas
   c) Kidney
   d) Spleen
   Answer: b
   Explanation: Insulin is secreted by the beta cells of the Islets of Langerhans in the pancreas.

2. What is the function of insulin? (UPPSC 2020)
   a) Increases blood pressure
   b) Regulates body temperature
   c) Controls blood sugar level
   d) Helps in blood clotting
   Answer: c
   Explanation: Insulin lowers blood glucose levels by facilitating glucose uptake in cells.

3. Deficiency of insulin causes which disease? (BPSC 65th Prelims)
   a) Anemia
   b) Diabetes mellitus
   c) Goitre
   d) Rickets
   Answer: b
   Explanation: Lack of insulin or its effectiveness leads to diabetes mellitus.

4. Who discovered insulin? (BPSC 64th Prelims)
   a) Alexander Fleming
   b) Banting and Best
   c) Watson and Crick
   d) Edward Jenner
   Answer: b
   Explanation: Insulin was discovered by Frederick Banting and Charles Best in 1921.

5. Insulin is a: (UPPSC 2021)
   a) Carbohydrate
   b) Fat
   c) Hormone
   d) Enzyme
   Answer: c
   Explanation: Insulin is a peptide hormone responsible for regulating blood sugar.

6. In which form is glucose stored in the liver under the influence of insulin? (BPSC 63rd Prelims)
   a) Starch
   b) Sucrose
   c) Cellulose
   d) Glycogen
   Answer: d
   Explanation: Insulin promotes storage of glucose as glycogen in liver and muscles.

7. Which type of diabetes occurs due to autoimmune destruction of beta cells? (BPSC 67th Prelims)
   a) Type 1
   b) Type 2
   c) Gestational
   d) Juvenile
   Answer: a
   Explanation: Type 1 diabetes results from the autoimmune destruction of insulin-producing cells.

8. Insulin is composed of: (UPSC CDS 2019)
   a) Amino acids
   b) Fatty acids
   c) Nucleic acids
   d) Glucose
   Answer: a
   Explanation: Insulin is a protein hormone made up of amino acids.

9. Which of the following is NOT regulated by insulin? (UPPSC 2022)
   a) Lipid metabolism
   b) Protein synthesis
   c) DNA replication
   d) Glucose uptake
   Answer: c
   Explanation: Insulin does not directly regulate DNA replication.

10. Which of the following hormones increases blood sugar levels? (BPSC 66th Prelims)
    a) Insulin
    b) Glucagon
    c) Adrenaline
    d) Melatonin
    Answer: b
    Explanation: Glucagon increases blood sugar by stimulating glycogen breakdown.

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NCERT-Based Questions (Q11–30)

1. Insulin is secreted by which cells of the pancreas?
   a) Alpha cells
   b) Beta cells
   c) Delta cells
   d) Acinar cells
   Answer: b
   Explanation: Beta cells in the Islets of Langerhans produce insulin.

2. What is the main function of insulin?
   a) Decreases blood pressure
   b) Enhances water reabsorption
   c) Facilitates glucose uptake by cells
   d) Stimulates hunger
   Answer: c
   Explanation: Insulin helps in cellular uptake of glucose, lowering blood sugar.

3. In which organ is insulin degraded?
   a) Pancreas
   b) Liver
   c) Kidney
   d) Spleen
   Answer: b
   Explanation: The liver is the primary site for insulin degradation.

4. What is the normal function of insulin in muscle cells?
   a) Inhibits protein synthesis
   b) Promotes glucose transport
   c) Blocks glycogen formation
   d) Enhances calcium absorption
   Answer: b
   Explanation: Insulin stimulates glucose transport into muscle cells for energy.

5. Which of the following is a hyperglycemic hormone?
   a) Insulin
   b) Glucagon
   c) Thyroxine
   d) Oxytocin
   Answer: b
   Explanation: Glucagon raises blood sugar levels; insulin lowers it.

6. What happens when insulin is not produced?
   a) Hypoglycemia
   b) Diabetes mellitus
   c) Hyperthyroidism
   d) Cretinism
   Answer: b
   Explanation: Absence or deficiency of insulin results in high blood sugar levels.

7. Insulin helps in the conversion of:
   a) Glycogen to glucose
   b) Glucose to glycogen
   c) Protein to glucose
   d) Glucose to protein
   Answer: b
   Explanation: Insulin promotes glycogenesis — storage of glucose as glycogen.

8. Which feedback mechanism regulates insulin secretion?
   a) Positive feedback
   b) Negative feedback
   c) Cyclic feedback
   d) None of the above
   Answer: b
   Explanation: Insulin secretion is controlled by negative feedback from blood glucose levels.

9. Which organ becomes less sensitive to insulin in Type 2 diabetes?
   a) Brain
   b) Liver
   c) Muscles and fat tissues
   d) Spleen
   Answer: c
   Explanation: Type 2 diabetes involves insulin resistance in muscle and adipose tissues.

10. Insulin is essential for the metabolism of:
    a) Water
    b) Vitamins
    c) Glucose
    d) Oxygen
    Answer: c
    Explanation: Insulin is crucial for glucose metabolism and energy production.

11. Insulin is chemically classified as a:
    a) Steroid
    b) Carbohydrate
    c) Polypeptide
    d) Lipid
    Answer: c
    Explanation: Insulin is a polypeptide hormone composed of amino acids.

12. Which of the following is an effect of insulin deficiency?
    a) Hypoglycemia
    b) Polyuria
    c) Bradycardia
    d) Osteoporosis
    Answer: b
    Explanation: Lack of insulin leads to excess glucose in urine causing frequent urination.

13. When was insulin first used to treat diabetes?
    a) 1910
    b) 1922
    c) 1935
    d) 1945
    Answer: b
    Explanation: Insulin therapy for diabetes began in 1922.

14. How many amino acid chains are there in insulin?
    a) One
    b) Two
    c) Three
    d) Four
    Answer: b
    Explanation: Insulin consists of two polypeptide chains: A and B.

15. Insulin acts on which receptor type?
    a) G-protein coupled receptor
    b) Tyrosine kinase receptor
    c) Ligand-gated ion channel
    d) Nuclear receptor
    Answer: b
    Explanation: Insulin binds to tyrosine kinase receptors on target cells.

16. Which is the primary site of insulin action for glucose uptake?
    a) Liver
    b) Brain
    c) Muscle and fat
    d) Kidney
    Answer: c
    Explanation: Muscle and adipose tissue are major sites of insulin-stimulated glucose uptake.

17. Excess insulin secretion causes:
    a) Hyperglycemia
    b) Hypoglycemia
    c) Glycosuria
    d) Ketosis
    Answer: b
    Explanation: Too much insulin lowers blood sugar leading to hypoglycemia.

18. Which organ is least dependent on insulin for glucose uptake?
    a) Brain
    b) Liver
    c) Muscle
    d) Adipose tissue
    Answer: a
    Explanation: Brain cells use glucose independently of insulin.

19. Which of the following hormones opposes the action of insulin?
    a) Growth hormone
    b) Glucagon
    c) Cortisol
    d) All of the above
    Answer: d
    Explanation: Glucagon, cortisol, and growth hormone counteract insulin effects.

20. What is the storage form of insulin in beta cells?
    a) Free insulin
    b) Proinsulin
    c) Insulin-RNA complex
    d) Glycogen
    Answer: b
    Explanation: Insulin is initially stored in an inactive precursor form called proinsulin.

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Predicted/Reference Book-Based Questions (Q31–50)

1. What is the molecular weight of human insulin?
   a) ~5000 Da
   b) ~15000 Da
   c) ~5808 Da
   d) ~2500 Da
   Answer: c
   Explanation: The molecular weight of insulin is approximately 5808 Daltons.

2. Which mineral is essential for insulin secretion?
   a) Calcium
   b) Magnesium
   c) Zinc
   d) Iron
   Answer: c
   Explanation: Zinc is involved in the crystallization and storage of insulin in beta cells.

3. Recombinant insulin was first produced using:
   a) Yeast
   b) Human liver cells
   c) Bacteria
   d) Fungi
   Answer: c
   Explanation: Genetically modified E. coli was used to produce recombinant human insulin.

4. The onset of action for regular insulin is approximately:
   a) Immediate
   b) 30 minutes
   c) 2 hours
   d) 4 hours
   Answer: b
   Explanation: Regular insulin typically starts working within 30 minutes of injection.

5. Which insulin type has the longest duration of action?
   a) Lispro
   b) Regular
   c) NPH
   d) Glargine
   Answer: d
   Explanation: Insulin glargine is long-acting and lasts up to 24 hours.

6. Which is the first organ exposed to endogenous insulin?
   a) Kidney
   b) Liver
   c) Brain
   d) Heart
   Answer: b
   Explanation: The portal vein carries insulin from the pancreas directly to the liver.

7. What triggers insulin release?
   a) Low blood glucose
   b) Fasting state
   c) High blood glucose
   d) Hypothermia
   Answer: c
   Explanation: Elevated blood sugar levels stimulate insulin secretion.

8. Which hormone enhances insulin sensitivity?
   a) Cortisol
   b) Leptin
   c) Adiponectin
   d) Adrenaline
   Answer: c
   Explanation: Adiponectin improves insulin sensitivity and glucose regulation.

9. In insulin signaling, GLUT4 is:
   a) A receptor
   b) An enzyme
   c) A transporter
   d) A hormone
   Answer: c
   Explanation: GLUT4 is a glucose transporter activated by insulin in muscles and adipose tissue.

10. Which is NOT an effect of insulin?
    a) Promotes glycogenesis
    b) Promotes lipolysis
    c) Enhances protein synthesis
    d) Promotes glucose uptake
    Answer: b
    Explanation: Insulin inhibits lipolysis and promotes fat storage.

11. Which type of insulin is used in insulin pumps?
    a) Regular
    b) NPH
    c) Long-acting
    d) Rapid-acting
    Answer: d
    Explanation: Rapid-acting insulins like lispro are commonly used in insulin pumps.

12. Insulin resistance leads to:
    a) Type 1 diabetes
    b) Type 2 diabetes
    c) Hypoglycemia
    d) Hyperinsulinemia only
    Answer: b
    Explanation: Type 2 diabetes is characterized by insulin resistance in peripheral tissues.

13. In diabetes mellitus, urine contains:
    a) Protein
    b) Glucose
    c) Urea
    d) Hormones
    Answer: b
    Explanation: Due to high blood glucose, excess glucose is excreted in urine.

14. Which synthetic insulin is identical to natural human insulin?
    a) Pork insulin
    b) Bovine insulin
    c) Recombinant human insulin
    d) Analog insulin
    Answer: c
    Explanation: Recombinant insulin is bio-identical to human insulin.

15. Which of the following increases insulin release?
    a) Starvation
    b) Glucose intake
    c) Exercise
    d) Sleep
    Answer: b
    Explanation: Glucose ingestion stimulates beta cells to release insulin.

16. Which insulin analog has ultra-rapid onset?
    a) Glulisine
    b) Glargine
    c) Detemir
    d) Regular insulin
    Answer: a
    Explanation: Glulisine is an ultra-rapid acting insulin analog.

17. Somogyi effect is related to:
    a) Hypoglycemia at night followed by hyperglycemia
    b) Persistent hypoglycemia
    c) Insulin allergy
    d) Ketosis
    Answer: a
    Explanation: The Somogyi effect is a rebound hyperglycemia after night-time hypoglycemia.

18. Lipodystrophy at injection sites is a complication of:
    a) Oral hypoglycemics
    b) Insulin therapy
    c) Thyroxine
    d) Steroids
    Answer: b
    Explanation: Repeated insulin injections can cause fat atrophy or hypertrophy at sites.

19. What is the role of C-peptide in insulin?
    a) It helps glucose metabolism
    b) It indicates endogenous insulin production
    c) It increases insulin activity
    d) It blocks glucagon
    Answer: b
    Explanation: C-peptide is a byproduct of insulin synthesis used to measure natural insulin production.

20. What is insulin shock?
    a) Sudden increase in insulin production
    b) Severe hypoglycemia due to insulin overdose
    c) Allergic reaction to insulin
    d) Ketoacidosis
    Answer: b
    Explanation: Insulin shock refers to dangerously low blood sugar from excess insulin.