32 - Amino Acid Synthesis Flashcards
Intermediate molecules from 3 pathways are used to synthesize amino acids. What is used from glycolysis? TCA cycle? Pentose phosphate pathway?
3-phosphoglycerate; Phosphoenolpyruvate; Pyruvate
Alpha-ketoglutarate; OAA
Ribose-5-phosphate; Erythrose-5-phosphate
Remember, only 10 of the 20 amino acids are synthesized de novo in humans. The rest are ________.
Essential
***PVT TIM HALL (FVW TIM HRKL)
Note that essential amino acids tend to be _________ syntheses.
Secondary
In amino acid syntheses, one mechanism is transamination reactions. Pyruvate is exchanged with ________ via SGPT. OAA is exchanged with _______ via SGOT. Alpha-ketoglutarate is exchanged with ________ via Glutamate Dehydrogenase.
Alanine
Aspartate
Glutamate
With Aspartate, Glutamine donates an ______ to Aspartate to form _________.
-NH3
Asparagine
In other organisms, Aspartate can be modified to create ________, ________, and ________. These reactions are tightly regulated by feedback inhibition.
Lysine
Methionine
Threonine
Glutamine synthetase converts _________ to Glutamine. Glutamine is formed in cells as a way to transport free _______ to the liver.
Glutamate
NH4+
Synthetases use ______, synthases do not.
ATP
Adenylylation is the addition of an…
AMP ribonucleotide
Adenylylation inactivates _______ _______.
Glutamine synthetase
Uridylylation is the addition of a…
UMP ribonucleotide
Feedback inhibition: Glutamine maintains PII in its inhibitory form (______).
-UMP
Feedforward activation: Alpha-ketoglutarate and ATP maintain PII in its activating form (______).
+UMP
Glutamine is formed in cells as a way to transport free NH4+ to the liver. After a couple reductions and a cyclization, _______ is formed. After one reduction and a transamination, ________ is formed. Remember, this is just Arginine minus urea.
Proline
Ornithine
3-phosphoglycerate undergoes three reactions to get to ________.
Serine
3-phosphoglycerate undergoes three reactions to get to Serine. Then with a little help from Vitamins B6 and B12, the side chain is removed from Serine, leaving behind ________.
Glycine
In humans, Serine is converted to Cysteine through a…
Homocysteine intermediate
Tyrosine is a catabolic intermediate of __________.
Phenylalanine
Aromatic amino acids are derived from intermediates originating in the Pentose Phosphate Pathway. Histidine is synthesized from ___________. Tryptophan, Phenylalanine, and Tyrosine synthesis begins by combining _________ and _________ to make Chorismate.
Ribose-5-phosphate
Erythrose-4-phosphate; Phosphoenolpyruvate
The branched amino acids Valine, Leucine, and Isoleucine are synthesized from _________. These three amino acids:
1) Have complex syntheses
2) Only exist to be incorporated into _________
3) Syntheses are regulated by feedback inhibition
Pyruvate
Proteins
What are the 2 central amino acids that are able to convert to many different uses?
Glycine
Serine
A glycine derivative is _______.
Heme
Glycine and acetate are used to make heme. Acetate is converted to ________ prior to assembly. Animals and legumes make heme to facilitate the transport of ________. Heme is the main source of dietary _______.
Succinyl-CoA
Oxygen
Iron
This is the term for deficiencies in heme synthesis.
Porphyria
In porphyria (deficiency in heme synthesis), symptoms may vary by which protein is deficient. _______ enzyme deficiencies usually show symptoms related to pain and cardiac dysfunction. ________ enzyme deficiencies usually manifest as light-sensitivity and altered skin pigmentation.
Liver
Non-liver
The Revolutionary War may have been won in part because England’s “Mad King George” suffered from…
Acute Intermittent Porphyria
Pi orbitals in rings absorb photons, so if you change the ring, you change the gamma absorbed which changes the color transmitted. Heme is purple, Biliverdin is green, and Bilirubin is yellow. Each of these rings are changed, thus changing the colors we see with bruising! Remember, our eyes see the colors that are _________.
Transmitted
Glutamate-Derived molecules include _________ which is an antioxidant, _________ which stabilize DNA, and ________ which is an inhibitory neurotransmitter (conversely, Glutamate is an excitatory neurotransmitter itself).
Glutathione
Polyamines
GABA
Arginine -Derived molecules include _______ _______ which is a free radical, and _______ _______.
Nitric Oxide (NO) Creatine Phosphate
NOS (Nitric Oxide Synthase) has 3 isozymes: _________ (cardiac signaling), ________, and ________ cell. It is tied to G-protein signal cascade. _________ releases 3 equivalents of NO.
Endothelial
Neuronal
Immune
Nitroglycerine
The liver contains little Creatine Kinase, so it releases creatine into the bloodstream. Hydrolysis of the phosphate from Creatine Phosphate releases just about as much free energy as the hydrolysis of _______.
ATP
Creatinine is excreted in _______.
Urine
Synthesis of creatine uses more _______ than all other methylation reactions combined!
SAM
This is a Methionine-Derived molecule and is the primary methyl donor in cells.
SAM (S-adenosylmethionine)
This is a histidine-derived molecule. Histidine is decarboxylated with the help of pyridoxal phosphate to form _________.
Histamine
Histamine has many roles:
– Promotes secretion of ______ and _______ in the stomach
– _________ at site of trauma/allergic reaction
– Neurotransmission
HCl
Pepsin
Vasodilation
These are competitive inhibitors of histamine.
Antihistamines
This is a tryptophan-derived molecule and is a neurotransmitter. It is also a precursor for melatonin (light-dark cycle regulator), a vasoconstrictor to help regulate blood pressure, helps to navigate NOS, and helps to regulate bone mass.
Serotonin
Serotonylated proteins dictate the amount of ________ released from the pancreas.
Insulin
Serotonin causes _________ to contract around food. Secretion of increased amounts of serotonin results in toxins being rapidly expelled from the body, in either direction.
Intestines
__________ are derived from Tyrosine.
Catecholamines
This is a tyrosine-derived molecule. __________ is adrenaline, the “stress hormone”. It causes vascular constriction, increasing blood pressure (reviving heart) and ceasing inflammation (allergy). __________ is a neurotransmitter.
Epinephrine
Norepinephrine
This is a tyrosine-derived molecule. _________ signaling abnormalities are hallmarks of Parkinson’s disease, Schizophrenia, drug addiction, and ADHD.
Dopamine
What results from abnormal increased Dopamine?
Schizophrenia
Drug addiction
What results from abnormal decreased Dopamine?
Parkinson’s Disease
ADHD
______ can be modified to create Dopamine, or it can be acted upon by Tyrosinase to form _________ which is processed to form melanin pigments.
L-dopa
Dopaquinone
Albinism is a deficiency in ________ (no pigments produced because L-dopa isn’t converted to Dopaquinone by this).
Tyrosinase
Hair color is dictated by melanins. Dark hair is more _________ than _________, and light hair is more _________ than _________. Gray hair results from the cell death of melanin-producing cells.
Eumelanins; Pheomelanins
Pheomelanins; Eumelanins
