The digestion process of proteins begin with the action of an enzyme that is called pepsin. Pepsin is the protein digestive enzyme that is located in the stomach. The digestion of proteins occur in the stomach. The proteins are broken down into amino acids and these are absorbed in the small intestines and transported into the blood stream.
Homozygous is alleles which are the same, A way I remember it is Homozygous "Homo" which is know as the same so its hhtt or HHTT, heterozygous is when the alleles are different like tTHh, It is not found anywhere, it is terms to describe genotypes.