Amino Acid Metabolism Flashcards
Release of N, which can be used to make things like:
- purines and pyrimidines (based for DNA and RNA)
- heme (for cytochrome and hemoglobin)
- make Urea (excretory form of N)
which a.a. are branched chains? What is their function?
- valine
- leucine
- isoleucine
Function: to transport nitrogen from the liver to other tissues
which amino acids are essential in infants but not in adults
- histidine and arginine
infants do not yet make sufficient amounts
which amino acids are essential amino acids
Any Help in Learning These Little Molecules Proves Truly Valuable
arginine, histidine, isoleucine, leucine, threonine, lysine, methionine, phenolyalaline, tryptophan, valine
what is a complete protein?
contains a sufficient amount of EAA to support health
- in general, come from animal products
which amino acids contain sulphur?
methionine and cysteine
which amino acids can be phosphorylated?
serine, threonine and tyrosine
which amino acid is an alpha helix breaker?
proline
what are the three ways nitrogen can be incorporated into an amino acid?
- transaminiation (indirect)
- transamidation (indirect)
- direct incorporation
involves transferring an amino group from an amino acid to an alpha ketoacid
transamination
what is the keto acid we produce from alanine?
pyruvate
what is the keto acid we produce from glutamate?
alpha-ketoglutarate
what is the keto acid we produce from aspartate?
oxaloacetate
transaminations are which amino acids typically occur in the liver?
alanine and aspartate (ALT and AST)
involves transferring an amido group from an amino acid to an alpha ketoacid
transamidation
What is a direct way N is incorporated into an amino acid?
addition of N directly from ammonia
- can require a B3 coenzyme
which amino acids are in the glutamate family?
- Glutamine (add a nitrogenn)
- Proline
- Arginine
what is the enzyme for Glu to Gln?
glutamine synthetase
where does Gln go after converting from Glu?
To the liver for disposal via urea cycle
which amino acids are in the Asparate family?
- asparagine
- lysine (plants only)
- threonine to isoleucine (plants only)
- methionine (plants only)
which amino acids are in the pyruvate family?
alanine
valine
leucine
which type of amino acids can the liver not break down? What can the liver do with these?
BCAA’s
liver CAN use them to make proteins
instead, they are broken down by extrahepatic tissue for energy
leucine, isoleucine, and valine
which amino acids are in the serine family?
cysteine
glucine
what coenzyme is used by serine to make glycine?
B9 (folic acid)
serine = CH2OH
- B9 picks up H and water is released
when is folate used?
in one carbon transfers
- ser to glycine
- making purines and pyrimidines
what is folate first converted to?
THF
ex. MTHF - methyl THF, transfer methyl groups
what is folate stored as?
MTHF
- you need to be able to transfer the methyl group otherwise, it will be stuck in its methylated form
what amino acids are in the aromatic family?
tryptophan
tyrosine
phenylalanine
why is tyrosine non-essential?
we can make it from phenylalanine
histamine functions include
gastric acid production
allergic responses
wakefulness (CNS effect)
histidine can be ______ to histamine
decarboxylated
what are the 2 deamination pathways?
- glutamine synthetase - requires ATP
- glucose-alanine cycle - alanine carries N and doesn’t cost anything to make
what starts the urea cycle
a combination of ornithine and carbamoyl phosphate to make citrulline
how much ATP does it take to generate urea in the urea cycle?
4
how much ATP do we need to detoxify each amino group?
2
what is the storage group for carbs?
glycogen
what is the storage group for fatty acids?
triglycerides
why do we require essential amino acids on a daily basis?
no storage group - any extras will be broken down
arginase is only found in the _____
liver
how does the urea cycle connect to CAC?
via fumarate
