CBSE weightage: 7 marks. This unit is part of the official 70-mark Chemistry theory course for 2026–27. citeturn0search11

1. What You Need to Learn

Carbohydrates; proteins; enzymes; vitamins; nucleic acids; hormones and their biological roles.

2. Core Concepts & Formulae

Carbohydrates include monosaccharides, oligosaccharides and polysaccharides. Proteins are polymers of amino acids joined by peptide bonds and show primary, secondary, tertiary and quaternary structures. Enzymes are biological catalysts. DNA and RNA are nucleic acids built from nucleotides.

3. Common Mistakes

Learn structures and functions together. Distinguish reducing and non-reducing sugars, peptide bond and glycosidic linkage, DNA and RNA, and fat-soluble versus water-soluble vitamins. Use diagrams for glucose, amino-acid/zwitterion and nucleotide structures.

4. Exam-Focused Practice

1. Classify carbohydrates with examples.
2. Explain protein structure levels and denaturation.
3. Compare DNA and RNA.
4. Match vitamins with major deficiency diseases and explain the role of enzymes as catalysts.

5. Quick Revision Checklist

• Can you define the key terms without looking at the book?
• Can you explain the main trend/reaction/mechanism with a reason?
• Can you solve a numerical or predict a product independently?
• Can you answer an application or competency-based question?

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