Some proteins are so complex and chemically ‘solid’ that they cannot be broken down by digestion so the amino acids cannot be absorbed in the intestine.They accordingly have no dietary or nutritional value for the animal like hair for example.
Amino acids are the building blocks of proteins. Proteins contain a total of about 20 amino acids - 11 of which cats and 10 of which dogs must be provided through the diet as they are not produced by the body.
Amino acids from dietary proteins are the building blocks of all proteins synthesised by the body to ensure its vital operation and physiological functions.
All food proteins of animal or plant origin are composed of a series of chemically bound interlinked amino acids.