Question | Answer |
Curly arrow | movement of an electron pair to form/break a new covalent bond |
electronegativity | measure of attraction of a bonded atom for the pair of electrons in a covalent bond. |
zwitterion | dipolar ionic form of an amino acid formed by the donation of a hydrogen ion from the carboxyl group to the amino group. No overall charge |
Isoelectric point | pH value where the amino acids exists as a zwitterion |
Condensation polymerisation | monomers bond to form the polymer chain and water is eliminated from this reaction |
Condensation | two small molecules react together to form a larger molecule with the elimination of a small molecule e.g. water |
biodegradable | polymer that breaks down completely into carbon dioxide and water. |
degradable | polymer that breaks down into smaller fragments when exposed to heat or light. |
phase | physically distinct form of a a substance |
mobile phase | the phase that moves in chromotography |
stationary phase | the phase that does not move in chromotography |
chromatography | technique used for separating components in a mixture |
Adsorption | process by which a solid holds molecules of a gas or liquid as a thin film on the surface of a solid |
chromatogram | visible record showing the results of separation by chromotography |
Retention time | time taken in gas chromatography for a component to pass from the column inlet to the detector. |
enantiomers | optical isomer |
achiral | not an optical isomer |
racemic mixture | contains equal amounts of both optical isomers (racemates) does not rotate light |
stereospecific | one isomer interacts with the enzymes |
chirality | 4 different groups, do not superimpose |
chiral synthesis | enzyme produces one isomer |
chiral pool sythesis | start with one stereospecific isomer resulting in pure optical drug |
transition metal complexes | catalyses produce, one isomer |
synthetic | both isomers, need a stronger dose, cheaper, side effects |
Problems with synthetic | isomers difficult to separate due to the same chemical and physical properties |
natural | one isomer, need a weaker dose, expensive, no side effects, |
Problems with natural | enzymes are costly and time consuming |