nutr chapter 7

• proteins are made up of amino acids
• the body needs amino acids to function 11 nonessential amino acids and 9 essential amino acids
• nonessential amino acids are made by the body and don't need to be obtained from the diet
• essential amino acids must be obtained by food because the body can't make them
• nonessential amino acids are synthesized through transamination
• if amino group is lost and not transferred to another carbon skeleton, the process is called deamination
• amino acids are linked together by peptide bonds to form proteins
• dna-coded instructions determine shape, and thus function, of proteins
• primary structure- sequential order of amino acids and determines the protein's shape
• secondary structure- is a spiral or pleated sheet shape formed by weak chemical bonds between amino acids
• tertiary structure- is 3d shape that determines overall shape and function of protein
• quaternary structure- 2 or more separate polypeptides interacting
• denaturation is the alteration of a protein's 3d struture and destroys the protein's function
• the body's proteins are in a constant sate of breakdown, rebuilding, and repair called protein turnover
• if protein intake is less than losses, individual is in negative protein balane
• is protein intake is greater than losses, individual is in positive protein balance
• adult rda for protein intake is 0.8 g/kg of body weight
• amdr for protein is 10-35%
• pepsin in the stomach breaks down long polypeptide chains
• chyme entering the small intestine triggers the release of secretin and cholecystokinin (cck) hormones that release proteases
• proteins produce vital body structures
• proteins maintain fluid balance
• proteins contribute to the acid-base balance expressed in ph and act as buffers by pumping ions in and out of cells
• proteins form hormones, enzymes, and neurotransmitters
• proteins contribute to immune function
• antibodies are proteins tat are a key component of the immune systen
• proteins transport nutrients
• gluconeogenesis forms glucose only if carbohydrate intake is inadequate
• protein-energy malnutrition (pem) occurs in combination with a deficiency of energy
• marasmus develops slowly and is a lack of all nutrients, not just protein
• kwashiorkor occurs rapidly and is a sever deficiency of just protein
• 8 foods account for 90% of all food allergies, peanuts, tree nuts, milk, eggs, fish, shellfish, soy, wheat
• lacto-vegetarians include dairy
• lacto-ovo-vegetarians include eggs and dairy