I N: Metabolism of PRO & FAT Flashcards
what are the branched chain amino acids?
valine, leucine, isoleucine
___ is needed for the transport of amino acids
pyridoxine
during exercise, oxidation of what AAs increase?
alanine and leucine
_______ can be synthesized from phenylalanine; ________ from methionine
phenylalanine –> tyrosine
methionine –> cysteine
what does nitrogen balance measure?
body equilibrium - compares intake to output
N balance: 0 balance
maintenance, nitrogen equilibrium
N balance: + balance
NET GAIN of protein = infant, teenager, pregnancy, healing
N balance: negative balance
erosion of body protein; inadequate intake
Nitrogen balance formula***
(protein intake in grams / 6.25) - (urinary urea nitrogen + 4)
methods to determine protein quality
1) biological value (BV)
2) net protein utilization (NPU)
3) PDCAAS (protein digestibility corrected amino acid score)
what is biological value?
uses N BALANCE to determine FRACTION OF ABSORBED NITROGEN
eggs have a BV of?
100% = all the nitrogen absorbed is retained
what is net protein utilization?
measures the amount of protein ACTUALLY USED
what is PDCAAS?
(protein digestibility corrected amino acid score)
estimates % of protein in each food category that is ACTUALLY DIGESTED
plant vs. animal proteins
protein from animal products is generally better used and digested than that from plants
anabolism of DNA
DNA forms RNA on ribosomes, which forms the template which carries the plan to the cytoplasm
catabolism of proteins: what AA is involved?**
pyridoxine
first step of catabolism in proteins?***
deamination- splitting off of NH2 by hydrolysis in liver
after deamination of proteins, what happens?**
1) NH2 –> NH3/ammonia, toxic
2) keto acid –> oxidized for energy
what happens to the NH3/ammonia?**
1) UREA –> EXCRETED BY KIDNEYS = WASTE
2) purine –> uric acid
3) transamination to make NEW AA (non-essential ones)
what is deamination?
splitting off of NH2 by hydrolysis in liver