Protein digestion occurs in the stomach and the duodenum<span> through the action of three main enzymes: pepsin, </span>secreted<span> by the stomach, and trypsin and chymotrypsin, </span>secreted<span> by the pancreas. During carbohydrate digestion the bonds between glucose molecules are broken by </span>salivary<span> and </span>pancreatic<span> amylase.
Archaean cell wall don't have peptidoglycan, yet they may have <em>, polysaccharides, glycoproteins, or protein-based cell dividers </em>
Bacterial cell walls are made of peptidoglycan (likewise called murein), which is produced using polysaccharide chains cross-connected by abnormal peptides containing D-amino acids
