Exam 2 Peng 3 Flashcards
what factors make side chains different?
1) charge
2) length
3) aromatic rings
4) branched chain
how do you deaminate aromatic rings?
strong enzymes and oxidation
the 20 AA are converted to ___ intermediates products?
7 intermediate products, chemical rxn may convert one intermediate product to another
intermediate products directly enter intermediary metabolism, resulting in either the synthesis of?
glucose of lipid or energy production
what are he ketogenic amino acids?
leucine and lysine
what are the glucogenic AND ketogenic AA?
isoleucine, tryptophan, phanylalanine, tyrosine
what are the glucogenic AA?
everything except: leucine, lysine, isoleucine, typtophan, phenylalanine, tyrosine
what is the entry point for 3 carbon AA? What are these AA?
pyruvate; alanine, cysteine, serine, glycine, threonine, tryptophan, asparate and asparagine
what is the entry point for 5 carbon AA? examples?
alpha-ketoglutarate; glutaine, proline, arginine, histodine
how are alanine, cysteine and serine converted to pyruvate?
by transamination, oxidative deamination and desulfuration
tryptophan is catabolized to form?
alanine
asparate and asparagine are converted to?
oxyloacetate (OAA)
proline (oxidized) and glutamine (hydrolyzed) to form?
glutamate
arginine is hydrolyzed to produce?
ornithine in the urea cycle and converted to glutamate
**histidine converted to?
FlGlu
what does FlGlu do?
denates formino group to tetragydrofolate (THF)
THF is synthesized from?
folic acid
folic acid deficiency? tested how?
increased excretion to FlGlu in urine, espesially after intake of histidine; test by checking urine for folic acid
what all is converted to succinyl CoA?
methionine, valine, isoleucine, threonine
how does methionine convert to succinyl CoA? what intermediate products?
through a complicated 9 step process, requires ATP
1) SAM
2) Homocysteine
what is SAM? formed? activated methyl group in SAM transferred by?
S-adenosylmethionine
- formed when methionine condenses with adenosine triphosphate
- methyl transfered by methyltransferases to substrates
the reaction to SAM to SAH is?
irreversible
what is the importance of SAM?
MAJOR methyl donor
what is homocystein?catalyzed by?
resynthesis of methionine
- remethylated to form methione
- catalyzed by methionine synthase
homocystine reaction back to methionine is influenced by?
folic acid and B12
where is the methyl group for homocysteine produced from?
5-methyl THF (tetrahydrofolate)
what is THF? good carrier for what and why? carries where?
tetrahydrofolate is a good glycarbon carrier bc it has a pocket structurally to carry different types of carbons
*carries units to methionine, nucleotide synthesis, and alternative synthesis of glycine and serine
SAM and THF are both? difference is?
Both methyl transfer systems
*SAM can only transfer methyl group, THF can transfer many IC groups (aka with different oxidative states)
what is SAH? hydrolized to?
S-adenosylhomocysteine
*hydrolyzed to homocysteine and adenosine
elevatedlevels of SAH in plasma promotes?
oxydative damage, inflammation,andothelial dysfunction
what reduced the levels of homocysteine in plasma?
B6, B12, and folic acid
elevated levels of homocysteine are a marker for what diseases?
heart and cardiovascular diseases bc elevated levels lead to oxidative damage
homocystinuria and cystathionine are treated how?
by B6 and B12 to reduce the elevated levels of homocysteine and vascular disease
