AQA A-level Biology Topic 1 Review

A set of vocabulary flashcards covering key concepts from AQA A-level Biology Topic 1.

Monomer

The smaller units from which larger ones are made; 'mono' means one.

Polymer

Molecules made from a large number of monomers joined together; 'poly' means many.

Monosaccharide

The simplest form of carbohydrates, such as glucose, that serves as a monomer for polysaccharides.

Disaccharide

A carbohydrate formed from two monosaccharides, such as sucrose, maltose, or lactose.

Polysaccharide

A polymer made of many monosaccharides bonded together, like starch, cellulose, and glycogen.

Glycosidic Bond

The bond that forms between two monosaccharides during a condensation reaction.

Condensation Reaction

A chemical reaction that joins two molecules together, forming a chemical bond and eliminating a water molecule.

Hydrolysis Reaction

A chemical reaction that breaks a bond between two molecules, requiring the addition of a water molecule.

Starch

A polysaccharide that serves as a store of energy in plants, made from alpha glucose.

Cellulose

A polysaccharide that provides structural strength to plant cell walls, made from beta glucose.

Glycogen

A highly branched polysaccharide that serves as energy storage in animals, composed of alpha glucose.

Triglyceride

A type of lipid formed by a glycerol molecule bonded to three fatty acid molecules through ester bonds.

Phospholipid

A type of lipid containing a glycerol backbone, two fatty acids, and a phosphate group, forming cell membranes.

ATP (Adenosine Triphosphate)

A nucleotide derivative that serves as an immediate source of energy in metabolic processes.

Hydrophilic

A property of molecules that can interact with water.

Hydrophobic

A property of molecules that repel water.

Peptide Bond

The bond formed between two amino acids during a condensation reaction to produce a dipeptide.

Primary Structure (of proteins)

The specific sequence of amino acids in a polypeptide chain.

Secondary Structure (of proteins)

The local folded structures that form within a protein due to hydrogen bonding between amino acids.

Tertiary Structure (of proteins)

The three-dimensional shape of a protein, determined by the interactions between R groups.

Quaternary Structure (of proteins)

The structure formed when two or more polypeptide chains join together to form a functional protein.

DNA

Deoxyribonucleic acid, a polymer made of nucleotides that holds genetic information.

RNA

Ribonucleic acid, a polymer that transfers genetic information and assists in protein synthesis.

Nucleotide

The monomer unit of nucleic acids, composed of a phosphate group, a sugar, and a nitrogenous base.

Hydrogen Bond

A type of weak chemical bond that forms between hydrogen atoms and electronegative atoms.

Enzyme

A protein that acts as a catalyst to speed up biochemical reactions by lowering activation energy.