Proteins Flashcards
what are peptides?
amino acid chains with ~50 amino acids
what is a dipeptide?
2 joined amino acids
what is a tripeptide?
3 joined amino acids
what is a polypeptide?
10+ amino acids
what is a protein?
a polypeptide chain with 50+ amino acids
what is a peptide bond?
bonds between amino acids
what is the reaction in which peptide bonds are formed?
condensation reaction
what is denaturation?
the change in shape and thus function, that proteins undergo stemming from exposure to heat, acids, bases, salts, or mechanical digestion
what is primary structure?
a long polypeptide chain
what happenes during secondary structure?
hydrogen bonds attract and repel each other
what happens during tertiary structure?
the side chains of amino acids bond together
what happens during quarternary structure?
the side chains on different proteins bind together
in terms of protein digestion what happens in the stomach?
- gastrin stimulates the release of HCl from parietal cells
- HCL denatures protein and activates pepsinogen to form pepsin
what is pepsinogen?
the enzyme that breaks down proteins
in terms of protien digestion what happens in the small intestine?
- enzymes continue to break down the proteins
- Amino acids are transported to the liver through the portal vein
what is the role of the pancreas in protein digestion?
produces the enzymes necessary to break down proteins into amino acids
what is the role of the liver in protein digestion?
the site where amino acids are transported and are sent back into the blood to be picked up by body cells
what is trypsinogen?
an enzyme that breaks apart peptide bonds
what is transamination?
the process in which one amino acid is transformed into a different one
what is deamination?
the removal of an amine group
what are the DRIs for protein intake?
- RDA = 0.8 g/kg of body weight
- AMDR = 10-35% of total kcals
what are complete proteins?
protein sources that provide all 9 essential amino acids along with some of the nonessential amino acids
what are incomplete proteins?
foods deficient in one or more of the essential amino acids
what are complementary proteins?
a combination of foods such that the entire composition provides all essential amino acids
what is protein-energy malnutrition?
protein and kcal intake are too low which results in dietary protein being used for energy
what is kwashikor?
getting enough calories but not enough protein
