Biomolecules
Class 11 · Biotechnology
4 ideas in Class 11 Biotechnology, explained in plain words, with games and quizzes to practise.
Carbohydrates
Part of: Sweet Chains
Carbohydrates follow Cn(H2O)n from 2-to-10-unit oligosaccharides to giant polysaccharides. Glucose with four chiral centres yields 16 stereoisomers; D-L, anomer and epimer forms vary. Starch splits amylose 15 to 20 and amylopectin 80 to 85, glycogen branches like trees, cellulose resists guts and chitin armours insects.
Why it matters. Count arithmetic plus storage-structure splits answers sugar questions.
Formulas
- Monosaccharides follow Cn(H2O)n
- Stereoisomers equal 2 raised to chiral centres
- Glucose gives 16 stereoisomers
Key words
- Monosaccharide
- : Single sugar unit.
- Glycosidic bond
- : Sugar-joining linkage.
- Anomer
- : Hemiacetal-carbon variant.
- Epimer
- : One-carbon variant.
- Amylose
- : Linear blue-dyeing starch.
- Amylopectin
- : Branched brown-dyeing starch.
- Chitin
- : Insect armour polysaccharide.
Try it in two minutes
- Count 2 to the chiral power.
- Split amylose from amylopectin.
- Dye starch blue.
Try at home. Explain why cattle digest grass but humans cannot.
Greasy Chains
Part of: Sweet Chains
Natural fatty acids carry even carbons, read as 18:2 delta 9,12, split mono from poly unsaturation. Simple TAG and waxes esterify alcohols while amphipathic phospholipids build membranes and four-ringed cholesterol parents hormones and stiffens layers.
Why it matters. Notation reading plus head-tail logic answers lipid questions.
Key words
- Saturated
- : No double bonds.
- Unsaturated
- : One or more double bonds.
- Triacylglycerol
- : Triple ester energy store.
- Wax
- : Coating ester.
- Amphipathic
- : Water-loving plus water-shunning.
- Cholesterol
- : Steroid parent and stiffener.
Try it in two minutes
- Read 18:2 delta 9,12.
- Split same from mixed TAG.
- Face heads out, tails in.
Try at home. Explain why oils melt lower than fats.
Amino Acids and Proteins
Part of: Folded Chains
Twenty L-only amino acids vary by side chain, zwitterions balance charges at pH 7, peptide bonds shed water, chains run 50 to 2000 residues near 110 Da each, and sequence folds through helix-sheet into 3D teams pinned by disulphides, mapped on Ramachandran phi-psi plots.
Why it matters. Mass arithmetic plus level order answers protein questions.
Formulas
- Chains hold 50 to 2000 residues
- Mean residue mass is 110 Da
- 100 residues weigh about 11000 Da
Key words
- Side chain
- : Varying R group.
- Zwitterion
- : Dual-charge amino state.
- Peptide bond
- : Water-losing amino link.
- Residue
- : Chain-bound amino unit.
- Alpha helix
- : Rod-like hydrogen fold.
- Beta sheet
- : Side-by-side strand fold.
- Quaternary
- : Multi-subunit arrangement.
Try it in two minutes
- Vary only side chains.
- Lose water per bond.
- Fold line to team.
Try at home. Explain why boiling an egg never unboils.
Nucleic Acids
Part of: Code Chains
Base plus sugar makes nucleoside, plus phosphate makes nucleotide; DNA pairs deoxyribose-thymine against RNA ribose-uracil. A-T shares two bonds, G-C three, B-DNA rules stable while A twists right with 11 and Z left with 12, and mRNA, rRNA, tRNA divide message, machine and carrier jobs.
Why it matters. Pair-bond counts plus form facts answers code questions.
Key words
- Nucleoside
- : Base plus sugar.
- Nucleotide
- : Base plus sugar plus phosphate.
- Phosphodiester
- : Chain-linking bond.
- B-DNA
- : Stable right-handed form.
- Melting temperature
- : Half-denatured heat point.
- Anticodon
- : tRNA codon reader.
Try it in two minutes
- Add phosphate to nucleoside.
- Count 2 versus 3 bonds.
- Assign three RNA jobs.
Try at home. Explain why heating melts DNA.
What your child will practise
- Amino Acids and Proteins: Space Puzzle (Clue Puzzle)
- Amino Acids and Proteins: Space Quick Fire (Quick Fire)
- Carbohydrates: Ocean Puzzle (Clue Puzzle)
- Greasy Chains: Desert Quest (Flip and Match)
- Nucleic Acids: Candy Quick Fire (Quick Fire)
- Quiz: Amino Acids and Proteins (8 questions)
- Quiz: Carbohydrates (8 questions)
- Quiz: Greasy Chains (8 questions)
- Quiz: Nucleic Acids (8 questions)