AQA A-Level Biology UPDATED 2026
A+
• polymer -✓✓long molecules formed from combinations of many monomers joined
together
• condensation reaction -✓✓a chemical reaction in which two or more molecules join
and produces one water molecule
• hydrolysis reaction -✓✓A chemical reaction that breaks apart a larger molecule by
adding a molecule of water
• isomers -✓✓Compounds with the same chemical formulae but different structures.
• carbohydrates -✓✓compounds made from carbon, hydrogen and oxygen
(monosaccharides, disaccharides and polysaccharides), important energy store
• monosaccharide -✓✓simple sugars (glucose, fructose, galactose)
• disaccharide -✓✓two monosaccharides joined together by a glycosidic bond
• polysaccharide -✓✓many sugar units joined by a glycosidic bond
• maltose -✓✓α glucose + α glucose
• lactose -✓✓glucose + galactose
• sucrose -✓✓glucose + fructose
• where is lactose found? -✓✓milk
• where is maltose found? -✓✓germinating seeds
• where is sucrose found? -✓✓table sugar
• cellulose -✓✓polymer of β glucose
• starch -✓✓polymer of α glucose (amylose + amylopectin)
• what is the structure of cellulose? -✓✓long, unbranched chains of β glucose, insoluble
• where is cellulose found? -✓✓plant cell walls
, • why is cellulose strong? -✓✓chains linked by h bonds form microfibrils giving high
tensile strength to prevent osmotic lysis
• what is the structure of starch? -✓✓long, highly-branched, compact helix and insluble
• where is starch found? -✓✓energy stores in plants
• glycogen -✓✓storage form of glucose in animals, compact, highly-branched structure
• limits of the Benedict's test -✓✓isn't specific or sensitive
• what is the test for reducing sugars? -✓✓Benedict's test
• what colour will the solution be in the presence of reducing sugars? -✓✓green → red
(nearer red, higher conc reducing sugar)
• what is the test for starch? -✓✓iodine test
• if starch is present, what colour will the iodine be? -✓✓orange → blue-black
• covalent bond -✓✓a chemical bond in which two atoms share a pair of electrons
• ionic bond -✓✓the bond between two oppositely charged ions
• hydrogen bond -✓✓the attraction between a partially positive hydrogen atom(δ+) and
a partially negative atom(δ-)
• lipid -✓✓compounds mostly made from carbon and hydrogen (triglycerides and
phospholipids), energy store, thermal insulator, for buoyancy and protection
• triglyceride -✓✓1 glycerol + 3 fatty acid tails joined by an ester bond
• glycerol -✓✓a three-carbon alcohol with a hydroxyl group(-OH) attached to each
• fatty acid -✓✓a carboxylic acid made of a hydrocarbon chain + a terminal carboxyl
group
• saturated fatty acid -✓✓no double bonds between carbon atoms, maximising the
number of hydrogen atoms that can attach to the carbon skeleton.
• unsaturated fatty acid -✓✓a fatty acid with one or more double bonds between the
carbons (mono or poly)
A+
• polymer -✓✓long molecules formed from combinations of many monomers joined
together
• condensation reaction -✓✓a chemical reaction in which two or more molecules join
and produces one water molecule
• hydrolysis reaction -✓✓A chemical reaction that breaks apart a larger molecule by
adding a molecule of water
• isomers -✓✓Compounds with the same chemical formulae but different structures.
• carbohydrates -✓✓compounds made from carbon, hydrogen and oxygen
(monosaccharides, disaccharides and polysaccharides), important energy store
• monosaccharide -✓✓simple sugars (glucose, fructose, galactose)
• disaccharide -✓✓two monosaccharides joined together by a glycosidic bond
• polysaccharide -✓✓many sugar units joined by a glycosidic bond
• maltose -✓✓α glucose + α glucose
• lactose -✓✓glucose + galactose
• sucrose -✓✓glucose + fructose
• where is lactose found? -✓✓milk
• where is maltose found? -✓✓germinating seeds
• where is sucrose found? -✓✓table sugar
• cellulose -✓✓polymer of β glucose
• starch -✓✓polymer of α glucose (amylose + amylopectin)
• what is the structure of cellulose? -✓✓long, unbranched chains of β glucose, insoluble
• where is cellulose found? -✓✓plant cell walls
, • why is cellulose strong? -✓✓chains linked by h bonds form microfibrils giving high
tensile strength to prevent osmotic lysis
• what is the structure of starch? -✓✓long, highly-branched, compact helix and insluble
• where is starch found? -✓✓energy stores in plants
• glycogen -✓✓storage form of glucose in animals, compact, highly-branched structure
• limits of the Benedict's test -✓✓isn't specific or sensitive
• what is the test for reducing sugars? -✓✓Benedict's test
• what colour will the solution be in the presence of reducing sugars? -✓✓green → red
(nearer red, higher conc reducing sugar)
• what is the test for starch? -✓✓iodine test
• if starch is present, what colour will the iodine be? -✓✓orange → blue-black
• covalent bond -✓✓a chemical bond in which two atoms share a pair of electrons
• ionic bond -✓✓the bond between two oppositely charged ions
• hydrogen bond -✓✓the attraction between a partially positive hydrogen atom(δ+) and
a partially negative atom(δ-)
• lipid -✓✓compounds mostly made from carbon and hydrogen (triglycerides and
phospholipids), energy store, thermal insulator, for buoyancy and protection
• triglyceride -✓✓1 glycerol + 3 fatty acid tails joined by an ester bond
• glycerol -✓✓a three-carbon alcohol with a hydroxyl group(-OH) attached to each
• fatty acid -✓✓a carboxylic acid made of a hydrocarbon chain + a terminal carboxyl
group
• saturated fatty acid -✓✓no double bonds between carbon atoms, maximising the
number of hydrogen atoms that can attach to the carbon skeleton.
• unsaturated fatty acid -✓✓a fatty acid with one or more double bonds between the
carbons (mono or poly)
