NBS2 Exam 1: Biochem "Other" AA metabolism Flashcards
What are the three prodcuts of arginine metabolism?
ornithine –>Petrescine, NO and Creatinine, glutamic acid, proline
What enzyme converts arginine to petrucine?
ornithine decarboxylase converts ornithine to petrucine
what inhibits ornithine decarboxylase
eflorcine.
What does petrucine do?
It stabalizes DNA
What does efloricine do?
it blocks ornithine carboxylase which destroys the tyranosomes of african sleeping sickness. It alo can help with hituisim (growth of hair on a females face)
What does creatinine have to do with arginine?
You get creatinine from arginine which you use to measure GFR and kidney f(x)
how do we produce serine?
we divert from glycolysis (from G3P) using transaminase
serine can be broken down into what products?
glycine and pyruvate
The conversion of serine to glycine involves the use of what intermediate and what enzyme
Serine hydroxy methyltransferase which uses Tetrahydrafolate, It gains one carbon in the rxn. This can then be used to make purines or thymdine.
What happens in the breakdown of Glycine
It is broken down using glycine cleavage complex, which adds one carbons to THF, thus promoting nucelotide synthesis.
what happens when glycine cleavage complex is broken?
Glycine accumulates and is an inhibitory neutotransmitter. Severe mental disability, death frequntly during infancy
trace out serine metabolism
serine comes from G3P, it is broken down to glycine by serine hydroxy methyl transferase and creates a N5N10Folate in the process. Glycine can be broken down to oxaloacete (kidney stones) or is combusted to create more N5N10Folate leading to pyrimidine synthesis
histidine metabilism is important why? (tell me about its metabolism)
Histidine is broken down into FIGLU. FIGLU can only be broken down further if folate is added. When folate is added, it adds a C in order to produce N5N10THF for 1 carbon metabolism and the synthetis of nucelic acids
if you have increased FIGLU
your folate stores may have been depleted
what AA break down and add to the folate pool?
Serine, glycine, histidine and tryptophan
What is the folate trap?
The folate trap is a result of having the folate intermediates converted to methyl THF. Methyl THF is not in equilibrium with the rest of the methyl products. You need to use homocysteine and B12 to convert Methyl THF to THF. If you dont have B12, your folate stores will get trapped as methyl THF and you will lose your ability to make folate, thus inhibiting the ability to synthesize DNA. This leads to macrocytic anemia
Why is B12 important in relation to folate
need B12 to convery Methyl THF to THF, which i used in 1 carbon metabolism to synthesize DNA
B12 deficiency leads to
macrocytic anemia due to the deplation of the folate stores. You may also get homocysteneuria since homocysteine cannot be converted back to methionine int he remethylation pathway
first step in the break down of methionine?
You add 3 ATP to methionine and get s-adenosyl methionine,
s-adenosyl methionine is used in
Is a carbon donor and is important in the methylation of histones
S adenosyl methioine (from methionine) is broken down into
s adenosyl homocysteine
s adenosyl homocysteine is broken down into
homocysteine
Homocysteine reacts with what amino acid?
serine
when homocysteine reacts with serine, what enzyme do they use and what do they form?
cystathionine synthase converts homocysteine and serine into cystathione.
