All Free Biochemistry MCQs with Answers

• A. Myoglobin
• B. Cytochrome
• C. Pyruvate kinaseConsult A Nutritionist
• D. Catalase

Explanation: Iron is present in the heme groups of myoglobin, cytochromes and catalase.

• A. Cow's milk
• B. Human milk
• C. Egg yolk
• D. Rice

Explanation: Rice contains very little calcium compared with milk and egg yolk, making it the poorest source listed.

• A. Transferrin
• B. Ferritin
• C. Apoferritin
• D. Lactoferrin

Explanation: Transferrin binds iron in the blood and transports it to tissues. Ferritin and apoferritin are mainly involved in iron storage, while…

• A. Ascending colon
• B. Middle segment of small intestine
• C. Proximal segment of small intestine
• D. Ileum

Explanation: Calcium absorption is greatest in the proximal small intestine, especially the duodenum, where vitamin D-dependent transport is active.

• A. 1gm
• B. 10 microgram
• C. 10 mg
• D. 20 mg

Explanation: An adult man generally needs about 10 mg of dietary iron daily, although only roughly 1 mg is absorbed to replace normal losses.

• A. Zn++
• B. Ca++
• C. Cu++
• D. Selenium

Explanation: Zinc is the second most abundant trace element in the human body after iron.

• A. Chromium
• B. Zinc
• C. Copper
• D. Potassium

Explanation: Zinc deficiency impairs growth and sexual development and commonly causes loss of taste, called hypogeusia or dysgeusia.

• A. Phytates
• B. Phosphates
• C. Tannins
• D. Ascorbic acid

Explanation: Ascorbic acid reduces ferric iron to the more absorbable ferrous form and improves intestinal iron absorption.

• A. Tryptophan
• B. Theronine
• C. Tyrosine
• D. Histidine

Explanation: Tryptophan is converted to niacin through kynurenine pathway intermediates, although the conversion is relatively inefficient.

• A. Both A and B
• B. Formation of osteoid matrix
• C. Calcification of osteoid
• D. Maturation of procollagen

Explanation: Vitamin C is required for hydroxylation during procollagen maturation and supports formation of the collagen-rich osteoid matrix.

• A. Vitamin B complex
• B. Vitamin C
• C. Iron
• D. Calcium

Explanation: Cereals provide several B vitamins and minerals but are generally poor sources of vitamin C.

• A. V a
• B. VIII a
• C. VIII a and V a
• D. None of the above

Explanation: Activated protein C, with protein S as a cofactor, inactivates factors Va and VIIIa.

• A. James lind
• B. Fracastorius
• C. John snow
• D. Edward Jenner

Explanation: James Lind demonstrated that citrus fruits could prevent and treat scurvy among sailors, establishing the importance of vitamin C.

• A. Perleche
• B. Pellagra
• C. Beri beri
• D. Nyctalopia

Explanation: Niacin deficiency causes pellagra, classically remembered by the three Ds: dermatitis, diarrhoea and dementia.

• A. Hemolytic anemia
• B. Posterior column abnormalities
• C. Autonomic dysfunctions
• D. Cerebellar ataxia

Explanation: Vitamin E deficiency causes oxidative hemolysis and neurological problems such as posterior-column involvement and cerebellar ataxia.

• A. The synthesis of clotting factors
• B. The microsomal hydroxylation reactions
• C. Antioxidant mechanisms
• D. Post translational modifications

Explanation: Both vitamins participate in post-translational modification: vitamin K gamma-carboxylates clotting proteins, while vitamin C hydroxylates…

• A. Thiamine levels in blood
• B. Transketolase activity in RBC
• C. Alkaline phosphatase levels in blood
• D. Plasma pyruvate and lactic acid levels

Explanation: Thiamine pyrophosphate is required by erythrocyte transketolase, so reduced transketolase activity is a useful functional test for…

• A. Riboflavin
• B. Thiamine
• C. Biotin
• D. Pyridoxine

Explanation: Raw egg white contains avidin, a protein that binds biotin and prevents its absorption.

• A. Defective collagen synthesis
• B. Soft swollen gums
• C. Subcutaneous & other hemorrhage
• D. Pigeon chest

Explanation: Vitamin C deficiency impairs collagen formation, producing swollen gums and bleeding from fragile blood vessels.

• A. Vitamin folic acid
• B. Vitamin B6
• C. Vitamin K
• D. Niacin

Explanation: FIGLU accumulates and is excreted in urine when folate-dependent histidine metabolism is impaired, making the test useful for detecting…