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.
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
reaction, using a reagent called
In industry a fungus called
synthesis penicillin through aerobic respiration.
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
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
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
- 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
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