Specificity of Enzymes:

The specificity of different enzymes is determined by the shapes of their active sites. The active sites possess specific geometric shapes that fit with specific substrates. There are over 2000 known enzymes each of which is involved in one specific chemical reaction. Enzymes are also substrate-specific.

Protease: The enzyme protease (which breaks peptide bonds in proteins) will not work on starch (which is broken down by an enzyme amylase)

Lipase: The lipase enzyme acts only in lipids and digests them into fatty acids and glycerol.