essential amino acids Flashcards
which aa is essential only in neonates? why?
arginine
essential in neonates bc urea cycle is not fully functional yet
what are the 2 non-essential aa that are synthesized from essential aa?
cysteine- from methionine
tyrosine- from phenylalanine
what is the “sparing effect”?
when there is adequate cysteine and tyrosine in the diet, there is decreased requirement for methionine and phenylalanine, respectively
cysteine has C skeleton from ___ and SH from ___
C skeleton from serine
SH from methionine
how is arginine synthesized?
glutamate –> glutamate semialdehyde –> ornithine»_space;> arginine using enzymes of the urea cycle (except that arginiase is absent in these specific tissues)
how is proline synthesized?
glutamate –> glutamate semialdehyde –> spont cyclization + NADPH –> proline
how is glutamine synthesized?
glutamate –> glutamine by glutamine synthase
how is asparagine synthesized?
oxaloacetate –> aspartate (+NH4 from glutamine) –> asparagine
perfect protein has the same composition as?
our muscle
why are vegetable proteins incomplete?
they contain non-optimal mixtures of essential amino acids and have lower aa scores
what is protein complementation?
increasing the quality of vegetable proteins by adding beans or milk protein
which aa is ratest in the diet?
tryptophan
how are children’s protein requirements different? why?
children require higher calories from protein and higher quality proteins for growth
marasmus vs. kwashiorkor
marasmus = starvation kwashiorkor = inadequate protein, adequate calories --> since calories are OK, there is less mm catabolism
