Biochemistry Questions With Answers for Nursing Exams

Biochemistry plays an important role in nursing exams because it helps explain how the human body functions, how diseases develop, and how medications produce their effects. Topics such as metabolism, hormones, neurotransmission, and physiological regulation are commonly tested and often become challenging without strong conceptual understanding.

Biochemistry questions with Answers for nursing exams provide an organised practice through exam-oriented questions and detailed explanations. Reviewing these concepts regularly can strengthen problem-solving ability, improve understanding of key nursing topics, and build confidence for nursing entrance and licensure examinations.

Important Questions for Nursing Exams: Biochemistry Questions With Answers

This section provides a selection of important biochemistry questions, mirroring the format and depth expected in nursing entrance and licensure examinations.

Q1 Which hormone increases blood glucose primarily by stimulating hepatic gluconeogenesis?

(A) Insulin

(B) Glucagon

(C) Aldosterone

(D) Growth hormone

Answer: (B)

 Q1 Text Solution:

Explanation: Glucagon, secreted by pancreatic alpha cells in response to hypoglycemia, stimulates hepatic glycogenolysis and gluconeogenesis to raise blood glucose. Insulin lowers blood glucose by promoting uptake and storage. Growth hormone has longer-term hyperglycemic effects but acts via different mechanisms.

Concept: Hormonal regulation of glucose homeostasis.

Important Point: Glucagon acts mainly on the liver.

Confusing Point: GH and cortisol also raise glucose but are not the primary acute responders. 

Q2 Which ion movement underlies the rapid depolarization (phase 0) of the cardiac ventricular myocyte action potential?

(A) Inward calcium via L-type channels

(B) Inward sodium via fast voltage-gated Na+ channels

(C) Outward potassium via delayed rectifier K+ channels

(D) Inward chloride via channels

Answer: (B)

 Q2 Text Solution:

Explanation: In ventricular myocytes, phase 0 (rapid depolarization) is mediated by opening of fast voltage-gated sodium channels, causing a large inward Na+ current. The plateau (phase 2) is maintained by inward Ca2+ (L-type) and balanced with K+ currents; repolarization (phase 3) involves K+ efflux.

Concept: Cardiac action potential phases and ionic currents.

Important Point: Cardiac pacemaker cells differ — they lack a fast Na+-driven phase 0 (their upstroke involves Ca2+).

Confusing Point: Don't conflate ventricular myocytes' fast Na+-driven upstroke with nodal cells' Ca2+-driven upstroke.

 Q3 Which structure is the principal inhibitory neurotransmitter in the adult mammalian CNS?

(A) Glutamate

(B) GABA (gamma-aminobutyric acid)

(C) Acetylcholine

(D) Dopamine

Answer: (B)

Q3 Text Solution:

Explanation: GABA is the main inhibitory neurotransmitter in the mature CNS, acting via GABA_A (ionotropic chloride channels causing hyperpolarization) and GABA_B (metabotropic) receptors. Glutamate is the primary excitatory neurotransmitter. Balance of excitation/inhibition is crucial for function and avoidance of seizures.

Concept: Neurotransmitter roles and receptor types.

Important Point: Benzodiazepines potentiate GABA_A receptors to increase inhibition.

Confusing Point: Glycine is inhibitory too (mainly spinal cord) — don't mix up their distributions.

Q4 A patient has arterial blood gas: pH 7.25, PaCO2 60 mmHg, HCO3- 26 mEq/L. What is the primary disorder?

(A) Metabolic acidosis

(B) Respiratory acidosis

(C) Metabolic alkalosis

(D) Respiratory alkalosis

Answer: (B)

 Q4 Text Solution:

Explanation: Low pH (acidemia) with an elevated PaCO2 indicates respiratory acidosis due to CO2 retention (hypoventilation). The HCO3- of 26 mEq/L is slightly above normal but not high enough to indicate metabolic compensation; acute respiratory acidosis shows an elevated PaCO2 and falling pH.

Concept: ABG interpretation — primary vs compensatory changes.

Important Point: For acute respiratory acidosis, HCO3- rises ~1 mEq per 10 mmHg PaCO2 increase (chronic more).

Confusing Point: Don't mistake an elevated HCO3- alone for metabolic alkalosis — consider PaCO2 and pH.

 Q5 Which autonomic branch is mainly responsible for "rest-and-digest" functions?

(A) Sympathetic

(B) Parasympathetic

(C) Somatic

(D) Enteric

Answer: (B)

Q5 Text Solution:

Explanation: The parasympathetic nervous system promotes conservation of energy: decreased heart rate, increased GI motility and secretions, and stimulation of glandular activity. Sympathetic mediates "fight-or-flight" responses.

Concept: Autonomic division functional differences.

Important Point: Parasympathetic fibers often travel with cranial nerves (III, VII, IX, X) and pelvic splanchnics.

Confusing Point: “Enteric” can function independently but is modulated by both branches.

 Q6 Which enzyme begins carbohydrate digestion in the mouth?

(A) Pepsin

(B) Amylase (salivary)

(C) Lipase (gastric)

(D) Trypsin

Answer: (B)

Q6 Text Solution:

Explanation: Salivary (ptyalin) amylase initiates starch digestion by cleaving alpha-1,4 glycosidic bonds into oligosaccharides. Its activity is limited by stomach acid but begins carbohydrate breakdown before ingestion reaches the small intestine.

Concept: Enzymatic steps of digestion.

Important Point: Pancreatic amylase continues carbohydrate digestion in the small intestine.

Confusing Point: Salivary amylase does not digest disaccharides — brush border enzymes complete that.

Q7 Which segment of the nephron creates the hyperosmotic medullary interstitium necessary for urine concentration?

(A) Proximal tubule only

(B) Cortical collecting duct

(C) Loop of Henle (especially the thick ascending limb)

(D) Distal convoluted tubule

Answer: (C)

Q7 Text Solution:

Explanation: The countercurrent multiplier established by the descending limb (permeable to water) and ascending limb (actively transports NaCl but impermeable to water — especially thick ascending limb) creates a hyperosmotic medullary interstitium. This gradient enables water reabsorption from the collecting duct under ADH to concentrate urine.

Concept: Countercurrent multiplier and urine concentration.

Important Point: Thick ascending limb is the “diluting segment” and is target of loop diuretics.

Confusing Point: Descending limb is water-permeable but salt-impermeable — roles differ.

 Q8 Which clotting factor is a vitamin K-dependent factor?

(A) Factor VIII

(B) Factor V

(C) Prothrombin (Factor II)

(D) Fibrinogen (Factor I)

Answer: (C)

Q8 Text Solution:

Explanation: Vitamin K–dependent factors include II (prothrombin), VII, IX, and X, as well as protein C and S. Vitamin K is needed for gamma-carboxylation of glutamic acid residues enabling calcium binding and proper function. Warfarin inhibits vitamin K recycling, reducing levels of these factors.

Concept: Coagulation cascade vitamin dependence.

Important Point: Vitamin K deficiency prolongs PT (extrinsic pathway) primarily.

Confusing Point: Factor VIII is not vitamin K–dependent and is decreased in hemophilia A.

Q9 Which vitamin prevents neural tube defect?

(A) Vitamin C

(B) Folic acid

(C) Vitamin D

(D) Vitamin A

Answer: (B)

Q9 Text Solution:

Explanation: Folic acid (Vitamin B9) plays a crucial role in DNA synthesis, cell division, and formation of neural tissue during early embryogenesis. Deficiency of folic acid during early pregnancy, particularly in the first 4 weeks after conception, leads to neural tube defects (NTDs) such as:

• Spina bifida (incomplete closure of spinal column)

• Anencephaly (absence of major portions of brain and skull)

• Encephalocele (herniation of brain tissue through skull)
  Supplementation with folic acid before conception and during early pregnancy helps ensure normal closure of the neural tube, which occurs by the 28th day of gestation.
  Important Points:

• Recommended dose:

• • 400 μg/day for all women of reproductive age (before conception).

  • 600 μg/day during pregnancy.

  • 4 mg/day if previous pregnancy had NTD (high-risk group).

• Best sources: Green leafy vegetables, citrus fruits, liver, legumes, and fortified cereals.

• Usually started 3 months before conception and continued through the first trimester.
  Confusing Points:

• Vitamin B12 deficiency -> causes megaloblastic anemia, not neural tube defects (though both are involved in DNA synthesis).

• Vitamin A -> essential for epithelial growth and vision; excess causes teratogenic effects.

• Vitamin D -> for bone development, not neural tube formation.

• Vitamin C -> helps in collagen synthesis and wound healing.

 Q10 The nurse monitors potassium in patient on:

(A) ACE inhibitors

(B) Beta-blockers

(C) Diuretics

(D) Steroids

Answer: (A)

Q10 Text Solution:

Explanation: ACE inhibitors (Angiotensin-Converting Enzyme inhibitors) such as enalapril, lisinopril, and ramipril inhibit the conversion of angiotensin I -> angiotensin II, leading to vasodilation and reduced aldosterone secretion. Since aldosterone normally promotes potassium excretion, its inhibition results in potassium retention -> hyperkalemia. 

 Hence, the nurse must regularly monitor serum potassium and renal function (creatinine, BUN) to prevent dangerous complications like cardiac arrhythmias. This is particularly important in elderly patients and those with renal impairment or diabetes mellitus.

Important Points:

• Normal serum K+: 3.5–5.0 mEq/L

• ACE inhibitors cause ↓ Na+, ↓ BP, ↑ K+

• Avoid potassium-rich foods or K+ supplements during therapy.

• Combination with K+-sparing diuretics (e.g., spironolactone) increases risk of severe hyperkalemia.

• Monitor ECG for peaked T-waves (sign of hyperkalemia).
  Confusing Points:

• Loop diuretics (furosemide) and thiazides -> cause hypokalemia, not hyperkalemia.

• Beta-blockers may mildly raise K+ but not clinically significant.

• Steroids cause Na+ retention and K+ loss (opposite effect).

Nursing Exam Biochemistry Questions & Answers PDF Download

For comprehensive preparation, you can download the full set of Nursing Exam 2026 Biochemistry Questions & Answers PDF. This resource provides these important questions and detailed solutions for convenient offline study. 

How to use Important Solutions for Nursing Exams Biochemistry for exam preparation.

Effective preparation for nursing exams requires a systematic approach. Using these important biochemistry solutions can enhance your study routine:

• Understand Concepts First: Before attempting questions, review the explanations to grasp key biochemistry concepts like hormonal regulation or enzyme functions.

• Practice Questions Regularly: Work through each question and solution. This practice builds confidence and reinforces understanding of various physiological and biochemical processes.

• Review Difficult Topics: If a particular question or concept proves challenging, revisit related study materials. These solutions highlight areas needing more attention.

• Identify Key Topics: The range of questions helps identify key topics in Nursing Exam Biochemistry. Focus your study efforts on these frequently tested areas.

• Simulate Exam Conditions: Use these questions to practice answering under timed conditions. This improves speed and accuracy, crucial for exam success.

• Self-Assess Progress: Regularly check your understanding against the provided solutions. This helps track your learning and guides further study.