AA Metabolism I/II Flashcards
What is a key transport form of Nitrogen?
Glutamine
Most Amino groups harvested from AA are converted to ______ though the ______ cycle.
Urea
Urea
Purpose of Alanine aminotranferase?
Catalyzes the transfer of of the amino group of ALANINE to Alpha-ketoglutarate
What coenzyme plays a key role in AA degradation?
Pyridoxal Phosphate
What happens after Citrulline leaves the Mitochondrial matrix?
It condenses with ASPARTATE to form Argininosuccinate
AA degraded to Pyruvate, Alpha-Ketoglutarate, Succinyl CoA, Fumarate, or OAA are termed _____ ?
Glucogenic
Carbamoyl Phosphate reacts with ____ to begin the Urea Cycle?
Ornithine
What enzyme catalyzes the formation of ALA?
Where is it the enzyme present?
ALA Synthase
Present in the Mitochondria
What happens after Urea is produced from the Hydrolysis of Arginine?
It gets Excreted
Citrulline is Produced where?
Does it stay there?
In the Mitochondrial matrix
NO, it gets transported into the cytoplasm
What is the first step in the Biosynthesis of Porphyrins?
The Condensation of Glycine and Succinyl CoA to form Alpha-Aminolevulinate (ALA)
Production of Nitric Oxide
Precursor and Enzyme
Produced from Arginine
Catalyzed from NO Synthase
Fxn of ·NO
Vasodilation
Glutathione Peroxidase fxn?
The enzyme that catalyzes the peroxide detoxification.
What AA is a precursor of Serotonin?
Tryptophan
Alpha-Amino groups are converted to ______ by the oxidative deamination of ______?
Ammonium
GlutaMATE
What AA is a precursor of Epinephrine?
Tyrosine
Carbamoyl Phosphate if produced what two reactants?
CO2 + NH4+
Or
HCO3- + NH3
What AA is the precursor of Histamine?
Histidine
What enzyme synthesizes the formation of Carbamoyl Phosphate?
Carbamoyl Phosphate Synthase I
AA degraded to ACoA or Acetoacetyl CoA are termed _____ because they give rise to _______?
Ketogenic
Ketone Bodies or FA
What enzymes catalyze the transfer of an alpha-amino group to what kind of acid?
Aminotransferases
(Transaminases)
Alpha-KETOacid
Aside from Arginine, what are required for the synthesis for ·NO?
NADPH and O2
Carbamoyl Phosphate reacts with Ornithine to produce _______?
The rxn is catalyzed by what enzyme?
Citrulline
Ornithine Transcarbamoylase
The nitrogen atom from Glutamate is converted into _____ by the enzyme _____?
Free Ammonium
Glutamate Dehydrogenase
Why is Glutamate Dehydrogenase so unusual?
Because it can utilize either NAD+ or NADP+
Alanine + Alpha Ketoglutarate yields what products?
PYRUVATE and Glutamate
Think “PAL”
What AA is a precursor to Sphingosine?
Serine
Reaction to produce Ammonium
AA ——> Glutamate
Glutamate ——> Ammonium
What element is associated with Glutathione Peroxidase?
Selenium
Components of Glutathione?
Gamma-Glutamate
+
Cysteine
+
Glycine
(GCG)
Glutamate Dehydrogenase is inhibited by _____ and is stimulated by ______?
Inhibited by GTP
Stimulated by ADP
Urea is synthesized from what two Nitrogen sources?
Aspartate
&
Free NH4+
Aspartate + Alpha Ketoglutarate yields what products?
Oxaloacetate and Glutamate
Think “OX ASs”
What is the rxn of the enzyme Argininosuccinase?
Aka Argininosuccinate Lyase
Cleaves AS into ARGININE and FUMARATE
- Fumarate leave the cycle
What AA is a precursor of the Nicotinamide unit of NAD+?
Tryptophan
What AA is a precursor of Thyroxine?
Tyrosine
What is the purpose of the production of Fumarate?
Precursor for Glucose synthesis.
What is the Committed reaction of the Urea Cycle?
The formation of Carbamoyl Phosphate
Purpose of Aspartate Aminotransferase?
Catalyzes the transfer of the amino group of Aspartate to Alpha-Ketoglutarate
The purpose of the enzyme Arginase?
To hydrolyze Arginine to generate UREA and Ornithine
The carbon sources of AA come from what Pathaways?
- Glycolysis
- PPP
- TCA
Role of Glutathione
Serves as a sulfhydryl buffer and an Antioxidant
The production of Argininosuccinate is catalyzed by what enzyme?
What is the energy source?
Argininosuccinate Synthase
ATP ——> AMP
All defects in the Urea Cycle can lead to what disease?
Hyperammonemia
- elevated level of NH4+ in the BLOOD
Degradation of Heme
What energy source is required?
Heme ——>BiliVERDIN
———> BiliRUBIN
NADPH is used for both rxns
What happens after Ornithine is produced from the Hydrolysis of Arginine?
It gets shuttled back into the Mitochondrial matrix