Reusable, complex proteins that promote chemical reactions within cells are called

Correct Enzymes

Enzymes are the protein molecules which act as biological catalyst to speed up the rate of chemical reaction by lowering the activation energy of the chemical reaction without being used in the chemical reactions.

Enzymes are specific in nature, which means they have a specific shape and only a specific substrate will fit into its active site and carry out the reactions.

All the biochemical reactions which are occurring inside the body require enzyme, without enzyme the rate of biochemical reaction would be slow.

Example: Amylase - It is an enzyme which convert starch into the sugar.

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