was discovered by Paul Ehrlich in 1891 - originally developed to

cells, it was discovered it was taken up selectively by different cells. It was marketed against

In 1932 it was discovered that

was effective against bacterial infections. The effective functional group was

Another drug containing this group is

which was used to cure Winston Churchill of pneumonia.

Sulfonamides are

of an enzyme called

which is involved in the synthesis of

Sulfonamides do not kill bacteria but they are

The difficult stage of penicillin synthesis was

because it was susceptible to breaking in even slightly

conditions. Penicillin was first synthesised from a

in a

reaction, using a reagent called

In industry a fungus called

synthesis penicillin through aerobic respiration.

Penicillin has

chiral centres.

Chanel no 5 was a landmark perfume because for the first time,

aldehydes were used. One of these aldehydes was

which is synthesized through a

reaction.

Alarm pheromones are used to trigger a

response, for example by a guard bee from its sting chambers. For example,

is an alarm pheromone. Trail pheromones are

laid down by ants, each ant contains just

of trail pheromones.

Clavulanic acid is similar to penicillin in that it has a beta lactam ring. However, it is not effective as an antibiotic - it is used as a

Carbapenems are resistant to

and they are effective in both gram positive and negative bacteria. The

is a

inhibitor of beta-lactamases.

Vancomycin inhibits an enzyme that forms

between peptidoglycan chains, this causes the cell wall to break down. Vancomycin resistance can arise when the final amino acid at the end of the

molecule changes, so vancomycin can no longer bind.

Daptomycin is a substitute for vancomycin because it has less toxicity on the

It has a hydrophilic head and a hydrophobic tail. Many molecules integrate into the cell membrane and

form. Resistance is

and the mechanism of action is

The three tastes that trigger a response without molecules entering the taste cells are

This is because tastants bind to

on the cell surface membrane in a very specific way. Once bound, the receptor protein

which triggers a series of chemical reactions that lead to the release of a

For the other two tastes -

- ions bind to ion channels which assist ions in entering the taste cells.

When compounds in tea leaves are released by breaking down the cells, they undergo

When green pigments are oxidised, they turn

Studies have shown that adding milk to tea inhibits the

but some studies suggest that this effect may be

Polyphenols are

- generally involved in defence against UV radiation, pathogens or predators. They are responsible for

(the drying feeling in the mouth when drinking tea.)

The savoury taste comes from the many

in tea. Tea also contains chlorophylls and