2. These are insoluble in water.

3. Convert fats into fatty acids and glycerol.

Peptidases :

1. These are for hydrolysing proteins, proteoses, peptones and peptides.

2. These are soluble in water.

3. Convert proteins into amino acids.


(b) Amylase, sucrase, maltase and lactase 

Amylase : It hydrolyses starch into maltose, isomaltose and limit dextrin.

Sucrase ; Hydrolyses sucrose into glucose and fructose.

Maltase : Hydrolyses maltose into glucose molecules.

Lactase : Hydrolyses lactose into glucose and galactose.


(c) Passive and active absorption

Passive absorption :It is a physical process in which the absorption is along the concentration gradient. Energy is not used. Absorption is slow. It does not involve carrier molecules. Metabolic inhibitors have no effect.

Active absorption : It is a vital process in which the absorption is done against the concetration gradient. Energy is used up in the process. Absorption is rapid. It involves carrier molecules. Metabolic inhibitors reduce absorption rate.

(d) Essential and non-essential amino acid

Essential amino acids :
These cannot be synthesised inside the body. These must be taken with diet from outside the body. These are eight in number.e.g. isoleucine, leucine, lysine, methionine, valine, threonine, phenylalanine and tryptophan.

Non-essential amino acids :
These can be synthesised inside the body.  These may or may not be present in diet. These are twelve in number. e.g. alanine, arginine, asparagine, asparatic acids, cysteine, glutamic acid, glycine, histidine, proline, serine and tyrosine.