Study Set Content:
intact protein, folded into quaternary structure
catalyst
HCl
denatures protein, unfolded to reveal primary structure
enzyme
pepsin
Enzymatic digestion by pepsin begins to break the protein into shorter polypeptides
• The chyme leaves the stomach and enters the small intestine, where the majority of protein digestion occurs. The pancreas secretes digestive juices into the
small intestine
The chyme leaves the stomach and enters the small intestine, where the majority of protein digestion occurs. The pancreas secretes digestive juices into the small intestine, and these contain more enzymes to further break down
polypeptides
The two major pancreatic enzymes that digest proteins in the small intestine are
chymotrypsin and trypsin
Trypsin activates other protein-digesting enzymes called
proteases,
The two major pancreatic enzymes that digest proteins in the small intestine are chymotrypsin and trypsin. Trypsin activates other protein-digesting enzymes called proteases, and together, these enzymes break proteins down to
tripeptides, dipeptides, and individual amino acids.
• Tripeptides, dipeptides, and single amino acids enter the
enterocytes
• Tripeptides, dipeptides, and single amino acids enter the enterocytes of the small intestine using active transport systems, which require ATP. Once inside, the tripeptides and dipeptides are all broken down to single amino acids, which are absorbed into the
bloodstream
Whole proteins are chewed and swallowed into the stomach
Hydrochloric acid denatures proteins, unfolding their 3-D structure to reveal the polypeptide chain
Enzymatic digestion by pepsin forms shorter polypeptides
In the small intestine, trypsin, chymotrypsin, and proteases continue enzymatic digestion, forming tripeptides, dipeptides, and amino acids
In enterocytes, tripeptides and dipeptides are further broken down into amino acids, which are absorbed into the blood
• Once the amino acids are in the blood, they are transported to the
liver
Once the amino acids are in the blood, they are transported to the liver. As with other macronutrients, the liver is the (blank)for amino acid distribution and any further breakdown of amino acids, which is very minimal.
checkpoint
Then become part of the body’s amino acid pool.
Dietary amino acids
