Biochemistry
Bachelor of Science in Nursing • Semester 1, 2026
Water & Biomolecules | Carbohydrates | Amino Acids & Proteins | Lipids & Vitamins | Nucleic Acids
Instructions to Candidates
- Answer ALL questions in Section A (Objectives & Fill-ins).
- Answer any THREE questions from Section B.
- Answer any TWO questions from Section C.
- Write clearly and legibly. Draw structures where appropriate.
- Do not write anything in the margins.
Section A
40 MARKSPart I — Objectives (20 Marks). Answer ALL questions. Choose the most appropriate answer.
1. A loss of what percentage of total body water leads to the physiological signs of dehydration?
2. Amphipathic compounds consist of:
3. Which of the following is NOT a property of water?
4. A pregnant woman presents with suspected premature rupture of membranes. Which Bromothymol indicator result confirms this?
5. Which carbohydrate is used clinically in the treatment of hypovolemic shock?
6. Starch consists of:
7. Which glycosidic linkage is found in maltose?
8. A patient becomes bloated after drinking milk. They lack the ability to cleave which bond?
9. Which of the following is an alkyl (aliphatic, hydrophobic) amino acid?
10. At pH 1, amino acids are predominantly:
11. All amyloid fibrils share an identical secondary structure, which is:
12. The mutation in Marfan syndrome affects the protein fibrillin at which level of protein structure?
13. Which is a characteristic shared by both triacylglycerols and glycerophospholipids?
14. Which of the following lipids is also referred to as a "neutral lipid"?
15. Which fatty acid carries the highest risk of contributing to atherosclerosis?
16. Which vitamin deficiency causes increased fragility of red blood cells and muscle weakness?
17. A long-time alcoholic patient is especially susceptible to developing which deficiency disease?
18. Nucleoside analogs (e.g. AZT) inhibit DNA synthesis because they lack which chemical group?
19. The structural difference between Uracil and Thymine lies at which carbon atom?
20. A high content of which bases would increase the melting temperature of duplex DNA?
Part II — Fill in the Blanks (20 Marks). Answer ALL questions in this part.
Section B
30 MARKSAnswer any THREE questions from this section.
- Describe the unique physicochemical properties of water that make it essential for life, with reference to hydrogen bonding, solvent action, and thermal properties.
- Classify carbohydrates by size and functional group, giving one clinically relevant example of a monosaccharide, disaccharide, and polysaccharide.
- Describe the four levels of protein structure (primary, secondary, tertiary, and quaternary), explaining the type of bond or interaction that stabilizes each level.
- Classify lipids into simple, compound, and derived lipids, giving one example of each and stating one biological function.
- Describe the structure of a nucleotide and explain the difference between a nucleoside and a nucleotide.
Section C
30 MARKSAnswer any TWO questions from this section.
- Discuss the fat-soluble vitamins (A, D, E, and K), describing for each: one biochemical function, one deficiency disease/effect, and one dietary source.
- Describe the structure of DNA, including the Watson-Crick double helix model, base pairing rules, and the factors that influence the melting temperature (Tm) of a DNA duplex.
- Discuss enzyme-linked disorders of carbohydrate digestion using lactose intolerance as a case example. Include the enzyme involved, the bond affected, the biochemical basis of symptoms, and the dietary management.
