Chapter 4: Enzymes

Enzymes

Are ^^biological catalysts^^ made of ^^proteins^^. They ^^alter the rate of chemical reactions^^ without being chemically changed at the end of reaction and are specific nature.

Enzyme-Catalysed Reaction:

%%Amylase%% digests starch.
%%Cellulase%% digests cellulose (only in plants not in humans).
%%Protease%% digests proteins.
%%Lipase%% digests fats.

Characteristics of Enzymes:

Speed up chemical reactions.
Required in minute amounts.
Are specific.

Factors affecting Enzyme Activity:

%%pH%%: they work ^^best at optimum pH^^. As pH ^^moves away from the pH scale the rate of reaction decreases^^. A ^^change in pH causes the shape of active site to change.^^
%%Temperature%%: works ^^best at optimum temperature^^. At a temperature ^^above optimum temperature the enzyme denatures.^^
%%Enzyme and Substrate concentration%%: as the ^^substrate concentration increases the rate of reaction increases to an initial point to make reaction constant^^ + Increase in enzyme concentration increases rate of enzyme reaction.