Class 11 Biology Chapter 9 Biomolecules – Revision Notes

Quick revision notes for Class 11 Biology Chapter 9 (Biomolecules). These Class 11 Biology Chapter 9 notes are ideal for quick revision just before exams.

Carbohydrates

• Mono-, oligo-, poly-saccharides. Starch (plant), glycogen (animal) storage; cellulose structural.

Proteins

• Amino acids linked by peptide bonds.
• Structure: primary, secondary, tertiary, quaternary.

Lipids and Nucleic Acids

• Lipids: fatty acids, triglycerides, phospholipids, steroids.
• DNA (deoxyribose, A/T/G/C) vs RNA (ribose, A/U/G/C).

Enzymes

• Biological catalysts (mostly protein); lower activation energy; affected by temperature, pH, substrate concentration.

One-Line Summary

Biomolecules — carbohydrates, proteins, lipids, and nucleic acids — are the chemical building blocks of life, with enzymes (mostly proteins) catalyzing the biochemical reactions that sustain cellular metabolism.

Written by Satish

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