KEYWORDS 1:

UNIT ONE

PEPTIDE BOND

THE BOND BETWEEN THE AMINE GROUP OF ONE AMINO ACID AND THE CARBOXYL GROUP OF ANOTHER.

POLYPEPTIDE

IN A POLYPEPTIDE THERE IS ALWAYS ONE END WITH A FREE AMINO (NH2) GROUP: N-TERMINUS & ONE END WITH A FREE CARBOXYL (COOH) GROUP: C-TERMINUS.

H BOND

THE ATTRACTION BETWEEN A H ATOM AND AN ELECTRONEGATIVE ATOM, SUCH AS NITROGEN OR OXYGEN.

(1/10th The strength of a covalent bond).

IONIC BOND

Between two close, oppositely charged
R groups (+VE & -VE).

DISULPHIDE BRIDGE

• -S-S-

• Covalent bond between 2 cysteine A.A’s.

• Cysteine A.A have an R-Group with Sulphur in them

ENZYME

• A PROTEIN THAT ACTS AS A BIOLOGICAL CATALYST AND SO LOWERS THE E_a WITHOUT BEING USED UP/CHANGED (no perm change in structure) ITSELF.

ACTIVE SITE

A SEQUENCE OF A.A THAT MAKES UP THE REGION OF AN ENZYME

INTO WHICH THE SUBSTRATE FITS

IN ORDER TO CATALYSE A REACTION.

COMPLEMENTARY

Having shapes or chemical properties that fit together precisely, allowing two molecules to bind specifically.

LOCK AND KEY:

ONLY THE CORRECTLY SIZED KEY (SUBSTRATE) FITS INTO THE KEYHOLE (ACTIVE SITE) OF THE LOCK (ENZYME).

• ACTIVE SITE IS EXACT COMPLEMENTARU SHAPE AT OPTIMUM TEMP SO REACTIONS ARE FASTEST IN THESE CONDTIONS.

• FOLLOWING THE REACTIONS, THE PRODUCTS DONT FIT IN THE ACTIVE SITE, SO THEY ESCAPE, LEAVING THE ENZYME UNALTERED AND FREE TO CATALYSE MORE SUBSTRATE.

• LIMITATIONS INCLUDE THAT THIS SUGGESTS ENZYMES HAVE A RIGID STRUCTURE, BUT THIS IS UNTURE.

INHIBITOR

A SUBSTANCE WHICH REDUCES THE ACTIVITY OF AN ENZYME AND MAY BRING IT TO A HALT.

ISOMER

SAME MOLECULAR FORMULA, DIFFERENT STRUCTURE.

ESTER BOND

O=C-O JOINS FATTY ACID TO GLYCEROL

ORGANIC BASE

NITROGEN CONTAINING HETEROCYCLIC COMPOUNDS.

DNA - ATCG.

RNA- AUCG.

ATP

AN ACTIVATED NUCLEOTIDE FOUND IN ALL LIVING ORGANISMS, PRODUCED IN RESP AND ACTS AS AN ENERGY CARRIER.

LATENT HEAT OF VAPORISATION

Heat energy required to change liquid at BP to gas at same temperature.