Biomolecules

Class 11 · Biology

5 ideas in Class 11 Biology, explained in plain words, with games and quizzes to practise.

Chemical Analysis and Small Molecules

Part of: Small Molecules and Metabolites

Drying, burning and acid-splitting sort water, ash minerals and small solubles from big insolubles. Twenty amino acids branch from one carbon with pH-shifting ends; fatty acids chain into glycerides and membrane phospholipids; bases pair sugars with or without phosphate.

Why it matters. Ash proves minerals hide in life. Small-molecule maps decode every polymer.

Key words

Amino acid: : A small building block of proteins carrying an amino group and an acid group on one carbon.
Essential amino acids: : Amino acids the body cannot make, so the diet must supply them.
Fatty acid: : A long chain molecule with an acid end that builds fats and membrane lipids.
Glycerol: : A small three-carbon molecule that joins fatty acids to form fats.
Lipid: : Water-insoluble molecules like fats, oils and waxes that store energy and build membranes.

Try it in two minutes

Order wet, dry and ash steps.
Sort three amino acids by R.
Pair five bases with sugars.

Try at home. Weigh salad before and after drying.

Metabolites and Macromolecules

Part of: Small Molecules and Metabolites

Primary metabolites run known life jobs; secondary ones like pigments, alkaloids and rubber serve ecology and industry with murkier roles. Big insolubles bundle proteins, nucleic acids and polysaccharides; membrane lipid bits ride along as vesicles while water dominates cells.

Why it matters. Role clarity splits metabolite classes. Insolubility groups reveal cell architecture.

Key words

Primary metabolite: : A molecule with a known direct role in growth and daily life processes.
Secondary metabolite: : A molecule like pigments or rubber with ecological value but no direct growth role.
Macromolecule: : A large insoluble molecule such as a protein, nucleic acid or polysaccharide.
Alkaloid: : A nitrogen-rich plant compound with a strong action on animal bodies.

Try it in two minutes

Sort six compounds by class.
Name four macromolecules.
Rank cell components by share.

Try at home. List kitchen spices as secondary metabolites.

Proteins and Their Structure

Part of: Proteins and Polymers

Twenty amino acids chain into heteropolymers; diet supplies essential ones while bodies brew the rest. Collagen leads animals, RuBisCO leads the biosphere; hormones, antibodies, receptors and transporters diversify jobs. Sequences fold into helices, balls and subunit assemblies.

Why it matters. Sequence dictates folds; folds dictate jobs. Subunit counts decode haemoglobin.

Key words

Polypeptide: : A chain of amino acids joined by peptide bonds that folds into a working protein.
Peptide bond: : The link formed between two amino acids when a water molecule is removed.
Primary structure: : The exact order of amino acids in a protein chain.
Tertiary structure: : The complete three-dimensional folding of a polypeptide that gives its working shape.
Denaturation: : The loss of a protein's folded working shape under heat or pH stress.

Try it in two minutes

Sort essential versus made.
Match six proteins with jobs.
Order four structure levels.

Try at home. Read food labels for essential amino acids.

Polysaccharides and Nucleic Acids

Part of: Proteins and Polymers

Glucose homopolymers split into wall cellulose, helical starch and branching glycogen; fructose builds inulin; shell chitin armours arthropods. Nucleotides stack base, sugar and phosphate; purines pair pyrimidines; ribose marks RNA while deoxyribose marks DNA.

Why it matters. Monomer identity predicts polymer jobs. Sugar identity names the nucleic acid.

Key words

Cellulose: : A glucose polymer forming plant cell walls that humans cannot digest.
Starch: : The helical glucose polymer in which plants store food.
Glycogen: : The branched glucose polymer in which animals store food.
Nucleotide: : A unit of base, sugar and phosphate that chains into nucleic acids.
Purine: : A double-ringed nitrogen base of nucleic acids, namely adenine or guanine.
Pyrimidine: : A single-ringed nitrogen base, namely cytosine, thymine or uracil.

Try it in two minutes

Match each polymer with its monomer.
Test starch versus cellulose with iodine.
Sort bases into purines and pyrimidines.

Try at home. Drop iodine on potato and paper.

Enzymes in Action

Part of: Enzymes

Protein pockets plus rare ribozymes bind substrates, cross energy barriers and release products unchanged; heat-lovers work near boiling. Rates answer to temperature, pH, substrate load and rival blockers; six reaction classes organise thousands; helpers split into tight prosthetics, loose coenzymes and metal ions.

Why it matters. Barrier logic explains million-fold speedups. Blocker shapes inspire medicines.

Key words

Enzyme: : A protein catalyst that speeds a reaction without being used up.
Active site: : The pocket on an enzyme where the substrate fits and reacts.
Substrate: : The substance an enzyme acts upon and converts into product.
Cofactor: : A non-protein helper, such as a metal ion, that an enzyme needs to work.
Competitive inhibitor: : A molecule that blocks an enzyme by occupying its active site.

Try it in two minutes

Order bind, change, release.
Test one factor's curve.
Match three helpers.

Try at home. Time droppings with and without catalyst analogies.

What your child will practise

Chemical Analysis and Small Molecules: Space Quick Fire (Quick Fire)
Enzymes in Action: Ocean Puzzle (Clue Puzzle)
Metabolites and Macromolecules: Candy Quest (Flip and Match)
Polysaccharides and Nucleic Acids: Candy Quick Fire (Quick Fire)
Proteins and Their Structure: Desert Puzzle (Clue Puzzle)

Quiz: Chemical Analysis and Small Molecules (8 questions)
Quiz: Enzymes in Action (8 questions)
Quiz: Metabolites and Macromolecules (8 questions)
Quiz: Polysaccharides and Nucleic Acids (8 questions)

Biomolecules

Class 11 · Biology

5 ideas in Class 11 Biology, explained in plain words, with games and quizzes to practise.

Chemical Analysis and Small Molecules

Part of: Small Molecules and Metabolites

Why it matters. Ash proves minerals hide in life. Small-molecule maps decode every polymer.

Key words

Amino acid: : A small building block of proteins carrying an amino group and an acid group on one carbon.
Essential amino acids: : Amino acids the body cannot make, so the diet must supply them.
Fatty acid: : A long chain molecule with an acid end that builds fats and membrane lipids.
Glycerol: : A small three-carbon molecule that joins fatty acids to form fats.
Lipid: : Water-insoluble molecules like fats, oils and waxes that store energy and build membranes.

Try it in two minutes

Order wet, dry and ash steps.
Sort three amino acids by R.
Pair five bases with sugars.

Try at home. Weigh salad before and after drying.

Metabolites and Macromolecules

Part of: Small Molecules and Metabolites

Why it matters. Role clarity splits metabolite classes. Insolubility groups reveal cell architecture.

Key words

Primary metabolite: : A molecule with a known direct role in growth and daily life processes.
Secondary metabolite: : A molecule like pigments or rubber with ecological value but no direct growth role.
Macromolecule: : A large insoluble molecule such as a protein, nucleic acid or polysaccharide.
Alkaloid: : A nitrogen-rich plant compound with a strong action on animal bodies.

Try it in two minutes

Sort six compounds by class.
Name four macromolecules.
Rank cell components by share.

Try at home. List kitchen spices as secondary metabolites.

Proteins and Their Structure

Part of: Proteins and Polymers

Why it matters. Sequence dictates folds; folds dictate jobs. Subunit counts decode haemoglobin.

Key words

Polypeptide: : A chain of amino acids joined by peptide bonds that folds into a working protein.
Peptide bond: : The link formed between two amino acids when a water molecule is removed.
Primary structure: : The exact order of amino acids in a protein chain.
Tertiary structure: : The complete three-dimensional folding of a polypeptide that gives its working shape.
Denaturation: : The loss of a protein's folded working shape under heat or pH stress.

Try it in two minutes

Sort essential versus made.
Match six proteins with jobs.
Order four structure levels.

Try at home. Read food labels for essential amino acids.

Polysaccharides and Nucleic Acids

Part of: Proteins and Polymers

Why it matters. Monomer identity predicts polymer jobs. Sugar identity names the nucleic acid.

Key words

Cellulose: : A glucose polymer forming plant cell walls that humans cannot digest.
Starch: : The helical glucose polymer in which plants store food.
Glycogen: : The branched glucose polymer in which animals store food.
Nucleotide: : A unit of base, sugar and phosphate that chains into nucleic acids.
Purine: : A double-ringed nitrogen base of nucleic acids, namely adenine or guanine.
Pyrimidine: : A single-ringed nitrogen base, namely cytosine, thymine or uracil.

Try it in two minutes

Match each polymer with its monomer.
Test starch versus cellulose with iodine.
Sort bases into purines and pyrimidines.

Try at home. Drop iodine on potato and paper.

Enzymes in Action

Part of: Enzymes

Why it matters. Barrier logic explains million-fold speedups. Blocker shapes inspire medicines.

Key words

Enzyme: : A protein catalyst that speeds a reaction without being used up.
Active site: : The pocket on an enzyme where the substrate fits and reacts.
Substrate: : The substance an enzyme acts upon and converts into product.
Cofactor: : A non-protein helper, such as a metal ion, that an enzyme needs to work.
Competitive inhibitor: : A molecule that blocks an enzyme by occupying its active site.

Try it in two minutes

Order bind, change, release.
Test one factor's curve.
Match three helpers.

Try at home. Time droppings with and without catalyst analogies.

What your child will practise

Chemical Analysis and Small Molecules: Space Quick Fire (Quick Fire)
Enzymes in Action: Ocean Puzzle (Clue Puzzle)
Metabolites and Macromolecules: Candy Quest (Flip and Match)
Polysaccharides and Nucleic Acids: Candy Quick Fire (Quick Fire)
Proteins and Their Structure: Desert Puzzle (Clue Puzzle)

Quiz: Chemical Analysis and Small Molecules (8 questions)
Quiz: Enzymes in Action (8 questions)
Quiz: Metabolites and Macromolecules (8 questions)
Quiz: Polysaccharides and Nucleic Acids (8 questions)