how do these processes are carried out in human body:- 1. protein digetion 2. carbohyrate digestion

The digestion of carbohydrates begins in the mouth. Salivary amylase present in saliva breaks starch into maltose. The smaller carbohydrate molecules reaches the stomach. From there, it passes into duodenum where in the common duct, pancreatic juice containing amylase acts on it and further succus entericus secreted by small intestine completes its digestion. Carbohydrates gets converted into glucose.

The digestion of proteins starts in the stomach. The gastric juice contains pepsin which breaks down proteins into smaller molecules. Trypsin in pancreatic juice further emulsifies proteins into further smaller molecules and succus entericus in small intestines finally breaks it into amino acids.