colourless crystalline compound. Any of several bases that are derivatives of purine; a colorless crystalline organic base containing nitrogen; the parent compound of various biologically important substances.

bring into use or operation for first time.

likely or prone to be affected by. conditionally upon. An area of study at school, e.g. math, history. cause or force person or thing to undergo.

salt or ester of phosphoric acid. Salt of phosphoric acids.

recognizably different in nature.

To keep something from spreading.

begin or be reckoned from particular point in time or space.

arrangement of and relations between parts or elements of something complex. To plan, organize, or arrange the parts of something.

A path or way that you can walk.

having acquired much knowledge through study. To get knowledge or skills by study or experience.

expressive. what is meant by word, text, etc.. To express a particular idea or thought.

assembled or made from whatever is available, and so unlikely to be of highest quality. mark or wound made by scratching. To rub your skin with your nails to stop an itch.

compound consisting of nucleoside linked to phosphate group.

Careful plan or method for achieving a goal. Branch of military dealing with command.

(Of a person) well-known and highly respected. To make something clearly different from others.