Enzymes

Enzymes are…

catalysts produced by living things (biological catalysts)

Living things have…

thousands of different chemical reactions going on inside them all the time

The reactions going on inside the living things need to be…

carefully controlled - to get the right amounts of substances

To speed up a reaction, you could raise the temperature, however this would…

speed up the useful reactions but also the unwanted ones too

Living things produce…

enzymes which act as a biological catalysts

Enzymes reduce the need for…

high temperatures and we only have enzymes to speed up the useful chemical reactions in the body

Catalyst

A substance which increases the speed of a reaction, without being changed or used up in the process

Enzymes have special shapes, so they can…

catalyse reactions

Chemical reactions usually involve things either being…

split apart or joined together

Substrate

the molcule changed in the reaction

Every enzyme has an active site, which is…

the part where it joins on to its substrate to catalyse the reaction

Enzymes usually only work with…

one substrate, they’re said to have a high specificity for their substrate

For enzymes to work,…

the substrate has to fit into the active site

Lock and key mechanism

If the substrate’s shape doesn’t match the active site’s shape, then the reaction won’t be catalysed