Flashcards in Amino Acid Synthesis Deck (67):
What is the diff bet essential and non essential aa
We get essential aa from our diet. We can't get non essential aa from our diet--> we can synthesize them ourselves
What are the essential aa
5. Arg (insufficient in infants)
10. Met (can be recycled)
What can be made from the transamination rxns?
1. Alanine (pyruvate)
2. Aspartate (oxaloacetate)
3. Glutamate (alpha KG)
What are the non essential aa
What is a precursor to the production of urea
argenine; regenerate ornithine to restart cycle
What is a pseudo essential aa
argenine and methionine. Argenine bec essential when you have + N for ex in pregnant women and infants and you dont have this cycle to generate argenine. Methionine can be recycled in met homocysteine pathway.
What are the two reactions that require B12 as a cofactor
1. homocysteine pathway to form Met and THF
2. methylmalonylCoA --> succinyl CoA
Synthesis of non essential aa require ____ and ATP
3 ____is required to make serine which condenses with _____ to make cysteine. It gets demethoxylated and become glycine
Pyruvate can directly transaminate to:
Oxaloacetate can transanimtate to ______to make asparagine
alpha KG can transaminate to _____ to make ______.
Phenylalanine + hydroxylase forms:
3 Phosphoglycerate is the starting point for which aa?
Folate = ______ for glycine
methyl group acceptor
Once you have serine you can condense it with _____ to make cystathionine and rehydrate it with _____ to make ______
cystathione B synthase; cystathione gamme lyase; cysteine
Serine + _____ form cysteine
cysteine has a backbone from serine and S group from:
If your deficient in cystathione synthase you will have an excess of _____ in your system which is prominent in cardiovascular disease.
homocysteine. It can result from THF, B12, or B6 deficiencies.
Asparagine synthesis uses ___as N donor
Glutamine is the main repository for _____. Reversal of reaction produces ____
What are the different ways to make glutamate?
1. Transamination of alpha KG
2. Oxidative deanimation via glutamate dehydrogenase
3. Glutamine can be hyrolyzed with glutaminase
4. Several amino acids convert to Glu: Proline, Argenine/ornithine, Histidine
How do you make proline?
Catabolized to glutamate. The reversal of this reaction is the synthesis of proline.
How is tyrosine made?
By hydroxylation of phenylalanine; catalyzed by phenylalanine hydroxylase (which is deficient in PKU; requires tetrahydrobiopterin and NADPH)
what are some biological molecules derived from aa
3. Thyroid hormones
Removal of COO- requires the enzyme _____ which uses ___ as a cofactor
decarboxylase; pyridoxine (vitamin B6)
addition of OH requires the enzyme ____ _____ which requires _____ and ____as a cofactor
hydroxylases and oxidases; tetrahydrobiopterin, and ascorbate
addition of methyl group requires the enzyme ____ which uses ____ and ____ as a cofacfor
methyl transferase; tetrahydrofolate, SAM
Nuerotransmitter signals are _____. Some are degraded of altered in synaptic cleft which include ____ via acetylcholinesterase and norepinephrine via _____ _____. Some neurotransmitters are endocytosed, such as ____.
transient; acetylcholine; monoamine oxidase; serotonin
Acetylcholine is derived from:
choline + acetyl coA makes;
serine turns into ____when you take off carbon dioxide which can turn into choline by methylating it via SAM
What are some things that target acetylcholine metabolism
1. Botox: block Ach secretion
2. Cognex: slows acetylcholinesterase - potentiates it. Drug used for alzheimers
3. Sarin: blocks acetylcholinesterase. Once acetyl choline is released you get rigid convulsions.
4. Atropine: blocks acetylcholine receptor.
What is GABA derived from
glutamate (it gets decarboxylated via glutamate decarboxylase)
GABA is an _____neurotransmitter. It acts by increasing ____ permeability of post synaptic neuron
GABBA is deficient in ______ and epilepsy
Huntington's chorea. Spasticity is in common. Things are hyper firing bc their not being more negatively charged.
GABA inhibition in brain is potentiated by
valium, librium, and alcohol
What stuff comes from tyrosine
1. Thyroid hormones; T3 and T4
2. Neurotransmitters/hormones: DOPA, dopamine, norepi, and epi
3. Pigment compounds: melanin
In people who have Parkinson's in where dopamine is deficient they treat them with ____bc its not charged.
If DOPA gets shunted off to form dopaquinone from this you form ____
dopamine is increased in ____ and cocaine and amphetamines and decreased by ___ and haldol
Serotonin is derived from:
Trp is ____ then decarboxylated to form serotonin. Serotonin is a potent _____ found in brain, platelets and mast cells and is also considered a major regulator of mood.
what can serotonin be converted to. SSRIs block reuptake of serotonin.
melatonin in pineal gland.
Tryptophan is the precursor of ____, the ring portion of NAD and NADP
what is histamine derived from and how does this work
histadine; gets decarboxylated via histidine decarboxylase. Histamine acts as a potent vasodilator.
what is an H2 receptor antagonist that has similar structure to histamine
what is nitric oxide derived from
argenine via nitric oxide synthase. NO is a potent vasodilator and free radical which helps combat bacterial pathogens.
what is glutathione made from and what is it
Its a strong reducing agent. There is no gene or mRNA for GSH.
what is creatine phosphate made from
creatine phosphate can phosphorylate ADP to ____. Both creatine and creatine phosphate are metabolized to ____. Inc excretion of creatinine is indicative of kidney damage
Polyamines are positively charged and are made from____ Polyamines complex with ___ during compaction
ornithine and Met; DNA
what are the three polyamines
what is carnitine made from. what are the aa precursors?what is it used as?
trimethyllysine. Lysine, Met (SAM). acyl group carrier
where is heme synthesized
liver and bone marrow
what is the first step of heme synthesis
glycine + succinylCoA to make aminolevulinic acid (in mitochondria)
what is second step of HS
2 aminolevulinic acid to make prophobilinogen (in cytosol)
what is third step of HS
4 porphobilinogens to make linear tetrapyrrole (in cytosol)
what is the fourth step of HS
tetrapyrrole cyclization (in cytosol)
what is 5th step of HS:
side group rearrangments, addition of Fe++ (in mitochondria)
Tetrapyrrole cyclization requires enzyme uroporphyrinogen I synthase and the coenzyme:
uroporphyrinogen III cosynthase
Deficiencies in the Urophorphyrinogen enzymes can cause:
1. synthase (not making enough heme): acute intermittent; dark urine (liver defect), episodic bouts of irrational behavior, paralysis or severe pain, hypertension
2. cosynthase (dont get AP switch): congenital erythropoietic; premature destruction of RBS, red urine, skin is sensitive to light and red teeth
Fe++ is inserted by what to form heme
how is heme degraded
1. RBC break down in the spleen and release heme.
2. Heme gets degraded to biliverdin and CO and free Fe++
3. Biliverdin gets converted to bilirubin which is carried by albumin through the BS to the liver.
4. Bilirubin is converted to bilirubin diglucuronide for excretion into small intestine with bile.
What can liver damage or blocked bile ducts cause
Heme oxygenase makes