Amino Acid Synthesis Flashcards
What kind of aa’s are essential?
Ones that we cannot synthesize ourselves
What are the two pseudo-essential aa’s?
Arg - insufficient in infants
Met - can be recycled
What two things do most Non-essential amino acids need?
NADPH and ATP
What is considered a risk factor for CVD?
Elevated serum homocysteine levels
What may result in elevated serum homocysteine levels?
Deficiencies in THF, B12 or B6
What amino acids are synthesized by direct transaminations?
Ala from Pyr
Asp from OAA
Glu from alpha-KG
How is proline synthesized?
By the reversal of Proline catabolization to Glu
How is Tyrosine made?
By hydroxylation of phenylalanine catalyzed by phenylalanine hydroxylase
What is Phenylalanine hydroxylase?
A mixed function oxidase
Are neurotransmitters transient?
Yes
Which NT’s are rapidly degraded or altered in the synaptic cleft?
ACh via Acetylcholinesterase
Norepinephrine via monoamine oxidase
Dopamine via monoamine oxidase
What neurotransmitter get’s endocytosed?
Serotonin
What is ACh derived from??
Serine
What does botox do to ACh?
Blocks ACh secretion
What does Cognex do to ACh?
Slows acetylcholinesterase
What does Sarin do to ACh?
Blocks acetylcholinesterase
What does Atropine do to ACh?
Blocks acetylcholine receptor
What is GABA derived from?
Glutamate which is decarboxylated
What type of NT is GABA and how does it act?
It is an inhibitory NT that acts by increasing K+ permeability of post-synaptic neuron
In what cases is GABA decreased?
Huntington’s chorea
Epilepsy
What increases GABA?
Valium
Librium
Alcohol
What thyroid hormones come from Tyrosine?
T3
T4
What NT’s/Hormones come from Tyrosine?
DOPA
Dopamin
Norepinephrine
Epinephrine
What pigment compounds come from Tyrosine?
Melanin
What is Serotonin derived from?
Tryptophan which is hydroxylated then decarboxylated
How does Serotonin affect the body?
A potent vasoconstrictor in brain, platelets and mast cells
A major regulator of mood in the CNS
What can Serotonin be converted into?
Melatonin in the pineal gland (Makes you sleepy)
What increases serotonin levels?
SSRIs like Prozac and Zoloft
What is tryptophan a precursor for?
Nicotinate (niacin), the ring portion of NAD and NADP
What is Histamine derived from?
Histidine which is decarboxylated
What is histamine secreted by?
Mast cells
Lung
Gastric Mucosa
What’s the function of histamine?
It’s a potent vasodilator
What is Tagamet?
An H2 receptor agonist with similar structure to histamine
NO derived from what aa?
Arginine via the enzyme nitric oxide synthase
What is the function of NO?
It’s a potent vasodilator
What 3 aa’s make Glutathione(GSH)?
Glu
Cys
Gly
What kind of reducing agent is GSH?
A strong one
Is there a gene or mRNA for GSH?
Nope
What 3 aa’s make Creatine Phosphate?
Arg
Gly
Met
What does Creatine Phosphate phosphorylate?
ADP > ATP
What can store phosphate with increasing ATP levels as a result of Creatine Phosphate?
Muscle and Cardiac
What can creatine phosphate be metabolized into?
Creatinine
What does increased excretion of creatinine indicative of?
Kidney Damage
What are polyamides made from?
Ornithine
When do polyamines with DNA ?
During compaction
What is carnitine made from?
Trimethyllysine
How does carnitine act as an acyl group carrier?
Picks up acyl in cytoplasm, transfers to CoA in mitochondria then free carnitine returns to cytoplasm
Where is heme primarily synthesized?
Primarily in liver and bone
What are porphyrias?
Diseases of heme synthesis
What is congenital erythropoietic porphyria?
A defect in the enzyme cosynthase which results in large amounts of uroporphyrinogen I.
What are the symptoms of congenital erythropoietic porphyria?
Premature destruction of RBC’s
Red Urine
Teeth have strong red fluorescence
Skin Sensitive to Light
What are you a Vampire?
What is acute intermittent porphyria?
A defect in the enzyme uroporphyrinogen I synthase.
What are the symptoms of acute intermittent porphyria?
Dark urine (primarily liver defect)
Episodic bouts of irrational behavior
Paralysis or severe pain
Hypertension
What is toxic porphyria?
Chemical induced by drugs like Phenobarbital
Where do RBC’s break down?
In the spleen where they release heme
What does heme degrade into?
Biliverdin, CO and free FE2+
What does Biliverdin get converted into?
Bilirubin which is carried by albumin through the bloodstream to the liver
What is bilirubin converted into and where is it excreted?
It is converted into bilirubin diglucuronide for excretion into the small intestine with bile.
What does Liver damage or blocked bile ducts result in?
Jaundice
