What the board asks
We went through the ISC board papers, question by question, and matched each question to a topic. Here is what was asked, how often, and what was never asked.
Chemistry: 384 topics in the 2027 syllabus, across 10 units. The board has asked 252 of them at least once. 132 were never asked in the papers we checked.
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C10 Biomolecules
All the topics in Chemistry: Biomolecules
Asked topics first, the most asked at the top. Tap a topic to see what to write, the result, the years, and the real board questions.
21 topics shown
| # | Topic | Type | Marks | Times asked | Last asked | Status |
|---|---|---|---|---|---|---|
| 1 | Reducing and non-reducing sugars: examples, tests and reasonsDefine reducing sugar (reduces Tollens' or Fehling's reagent through a free aldehyde or ketone group), give examples of each kind, explain why sucrose is non-reducing (both anomeric carbons used in the glycosidic bond), and pick the odd one out in an MCQ. | Give reason | 1 | 4 papers | Specimen 2027 | Asked |
| 2 | Vitamin deficiency diseases and case-style questionsName the deficiency disease of each vitamin A, B1, B2, B6, B12, C, D, E, K, and from a short patient story name the vitamin to prescribe. | Statement | 1 | 4 papers | Specimen 2027 | Asked |
| 3 | Disaccharides: structures, glycosidic linkage, hydrolysis productsName the monosaccharide units and the glycosidic linkage in sucrose, maltose and lactose, draw their Haworth structures, say whether each is reducing, and write the hydrolysis of sucrose to invert sugar. | Structure or name | 2 | 3 papers | Specimen 2027 | Asked |
| 4 | Denaturation of proteins: definition, causes, everyday examplesDefine denaturation (loss of biological activity when heat, pH change or chemicals disturb the secondary and tertiary structure), give everyday examples, and state which structure is unaffected. | Give reason | 1 | 3 papers | Specimen 2027 | Asked |
| 5 | Reactions establishing the open-chain structure of glucoseWrite the equation for glucose with HI (heat), hydroxylamine, bromine water, acetic anhydride, nitric acid and HCN if asked, and state in one line what each reaction proves about the structure. | Reaction | 1 | 3 papers | 2026 | Asked |
| 6 | Bromine water test: glucose vs fructose with equationDescribe adding bromine water to each sugar: glucose decolourises it and is oxidised to gluconic acid (equation), fructose does not; conclude which is the aldose. | Tell apart (test) | 1 | 3 papers | 2026 | Asked |
| 7 | Amino acids: general structure, classification, zwitter ion, isoelectric pointWrite the general formula of an alpha-amino acid, classify amino acids (essential/non-essential; neutral, acidic, basic), draw the zwitter ion of glycine or another given acid, and define isoelectric point. | Structure or name | 1 | 3 papers | 2025 | Asked |
| 8 | Fat-soluble and water-soluble vitamins: classification and storageClassify vitamins A, B, C, D, E and K as fat soluble or water soluble with examples, and explain why water-soluble vitamins (B and C) must be taken regularly (excreted in urine, not stored). | Give reason | 1 | 3 papers | 2025 improvement | Asked |
| 9 | Peptide bond: definition and dipeptide from two amino acidsDefine the peptide linkage (-CO-NH- formed between COOH of one amino acid and NH2 of the next with loss of water) and draw the dipeptide from two given amino acids, circling the peptide bond. | Structure or name | 1 | 2 papers | 2026 | Asked |
| 10 | Fibrous and globular proteins: definitions and examplesDefine fibrous and globular proteins by molecular shape and solubility, and give examples of each or classify a named protein. | Statement | 1 | 2 papers | 2026 | Asked |
| 11 | Nucleic acids: nucleotide units, purine and pyrimidine basesName the three parts of a nucleotide, classify the bases as purines (adenine, guanine) and pyrimidines (cytosine, thymine, uracil), and say which bases occur in DNA and which in RNA. | Statement | 1 | 2 papers | 2026 | Asked |
| 12 | Osazone formation: glucose and fructose with phenylhydrazineWrite the reaction of glucose (and fructose) with excess phenylhydrazine, state that three molecules are used, and explain why glucose and fructose give the same osazone (C1 and C2 both react, rest of the molecule identical). | Reaction | 1 | 1 paper | Specimen 2027 | Asked |
| 13 | DNA vs RNA: differences and double helixGive three or four differences between DNA and RNA (sugar, bases, strands, function) and describe the double helix with complementary base pairing. | Comparison | 2 | 1 paper | 2026 | Asked |
| 14 | Carbohydrates: definition and classification with examplesDefine carbohydrates, classify them as monosaccharides (aldoses and ketoses), oligosaccharides (di, tri, tetra) and polysaccharides with one example each, and classify a given sugar. | Statement | 1 | never | Never asked | |
| 15 | D-L configuration of sugars from glyceraldehydeDraw D- and L-glyceraldehyde in Fischer projection and assign D or L to a given sugar by the position of the OH on the lowest chiral carbon; state that D/L is not the sign of rotation. | Structure or name | 1 | never | Never asked | |
| 16 | Reactions establishing the open-chain structure of fructoseWrite the reactions of fructose with HI, hydroxylamine, acetic anhydride and HCN that show a straight 6-C chain, a ketone at C2 and five OH groups, and state that it is not oxidised by bromine water. | Reaction | 1 | never | Never asked | |
| 17 | Cyclic structures of glucose and fructose; alpha and beta anomersDraw the Haworth (or cyclic Fischer) structures of alpha- and beta-D-glucopyranose and D-fructofuranose, mark the anomeric carbon, and give the evidence the open chain fails to explain (no Schiff's test, no NaHSO3 addition, pentaacetate does not react with NH2OH, two anomers). | Structure or name | 2 | never | Never asked | |
| 18 | Starch, cellulose and glycogen: units, linkages, importanceState the monomer, linkage type and function of starch (amylose and amylopectin), cellulose and glycogen, and two points on the importance of carbohydrates. | Statement | 1 | never | Never asked | |
| 19 | Primary, secondary, tertiary and quaternary structure: definitionsDefine each level of protein structure in one line each, naming the alpha-helix and beta-pleated sheet as secondary structures and the forces that hold each level. | Statement | 1 | never | Never asked | |
| 20 | Enzymes and hormones: elementary idea with examplesDefine an enzyme as a biological catalyst (mostly globular protein, specific) and a hormone as a chemical messenger from an endocrine gland, with one or two examples each. | Statement | 1 | never | Never asked | |
| 21 | Optical activity of amino acids: why glycine is inactiveState that alpha-amino acids other than glycine have a chiral alpha-carbon and are optically active, and explain that glycine (R = H) has no chiral carbon. | Give reason | 1 | 1 paper | 2025 improvement | Not in syllabus |
This list was made from the 2027 syllabus and checked with 9 board papers, including the 2027 specimen paper. It is not yet checked with the textbook.
The 10 topics Chemistry papers ask most
Counted on the board papers from 2018 to the 2027 specimen paper, which every unit has been checked against.
- 1.IUPAC names of coordination compounds from formulaC5 Coordination Compounds · asked 8 times since 2018
- 2.Faraday's first law: mass, charge, current or timeC2 Electrochemistry · asked 7 times since 2018
- 3.Give reasons: transition metal ions are coloured, some colourlessC4 d- and f-Block Elements · asked 7 times since 2018
- 4.Alcohols from Grignard reagent: 1, 2, 3 degreeC7 Alcohols, Phenols and Ethers · asked 7 times since 2018
- 5.Williamson's synthesis of ethersC7 Alcohols, Phenols and Ethers · asked 7 times since 2018
- 6.Identify A, B, C, D in a given reagent chainC8 Aldehydes, Ketones and Carboxylic Acids · asked 7 times since 2018
- 7.Identify compounds from formula and test results (case problem)C8 Aldehydes, Ketones and Carboxylic Acids · asked 7 times since 2018
- 8.Identify A, B, C: amide, Hoffmann and amine-test chainsC9 Organic Compounds containing Nitrogen · asked 7 times since 2018
- 9.Gibbs energy and maximum work from cell emfC2 Electrochemistry · asked 6 times since 2018
- 10.Coordination number and oxidation state of the central metalC5 Coordination Compounds · asked 6 times since 2018