AQA A LEVEL BIOLOGY

• Activation energy is the minimum amount of energy required for a reaction to occur, molecules/particles must be in the correct orientation
• Active site is a group of amino acids in an enzyme where the substrate fits to catalyse a reaction
• Anabolic reactions involve building more complex molecules from simpler ones, e.g., protein synthesis and photosynthesis
• ATP (adenosine triphosphate) is an activated nucleotide found in all organisms, produced during respiration, acts as an energy carrier
• Benedict's test is a biochemical reaction to detect reducing sugars, brick-red indicates a positive result
• Biuret test is a biochemical reaction to detect protein, purple/lilac indicates a positive test
• Catabolic reactions involve the breakdown of complex molecules into simpler products, e.g., cellular respiration and hydrolysis
• Condensation reaction occurs when monomers combine to form polymers, one water molecule is removed
• Covalent bond is the sharing of 2 or more electrons between 2 atoms
• Denaturation is the permanent change due to the unravelling of the three-dimensional structure of a protein
• Dipeptide is formed by the condensation of 2 amino acids
• Disaccharide is a sugar formed from 2 monosaccharides joined by a glycosidic bond
• DNA helicase is an enzyme that breaks hydrogen bonds between DNA bases
• DNA replication is the process where a DNA molecule unwinds and each strand acts as a template for a new strand
• Enzyme is a globular protein that acts as a catalyst, substrate specific
• Esterification is a reaction that produces an ester, involving a condensation reaction
• Fibrous proteins are long strands of polypeptide chains with cross-linkages due to hydrogen bonds
• Globular proteins are compact, roughly spherical in shape and soluble in water
• Hydrogen bond is a chemical bond formed between a hydrogen atom and the negative charge on another atom
• Hydrolysis reaction breaks covalent bonds in a larger molecule when water is added
• Hydrophilic molecules have an affinity for water
• Hydrophobic molecules are insoluble in water
• Isomers are organic molecules with the same molecular formula but different structures
• Macromolecules are very large molecules containing 1000+ atoms
• Monomer is a small molecule that combines to form a larger polymer
• Monosaccharides are single sugar monomers, all are reducing sugars
• Non-polar molecules have electrons shared equally
• Nucleotides are complex chemicals made up of an organic base, a sugar, and a phosphate
• Osmolarity is a measure of the concentration of a solution
• Polymer is a large molecule made up of repeating smaller molecules
• Polymerases are enzymes that catalyse the formation of long-chain molecules from basic units
• Polymerisation is the process of joining monomers to form a polymer
• Polypeptide is formed by the condensation of many amino acids
• Polysaccharides are macromolecules formed by many monosaccharides joined by glycosidic bonds
• Primary structure of a protein is the sequence & number of amino acids bonded by covalent bonds
• Purines are double ring nitrogenous bases: adenine and guanine
• Pyrimidines are single ring nitrogenous bases: cytosine, thymine, uracil
• Qualitative tests indicate if a substance is present or absent
• Quantitative tests allow determining the concentration of a substance
• Quaternary structure of a protein involves more than 1 polypeptide chain linked together