Nitrogen And Urea Cycle Flashcards
Name the steps and molecules in the Urea cycle?
1-Carbamoyl phosphate 2-citrulline 3-aspartate 4-argininosuccinate 5-arginine 6-ornithine
What is kwashiorkor disease?
A disease caused by the inability to synthesize body proteins due to a lack of some essential amino acids.
Symptoms include fatigue, lethargy, edema, changes and in skin pigment, and coma.
Treatment is eat more essential amino acids
Where do the components of urea originate?
Nitrogens come from free NH4 and aspartate
Carbon comes from CO2
During the urea cycle which molecule is transported into the mitochondrial matrix and which module is transported out of the mitochondrial matrix?
Citrulline is transported out.
Ornithine is transported in.
How much ATP is required to make one urea molecule?
2 are required to turn CO2 & NH4 to carbamoyl phosphate and 1 is required to convert aspartate to argininosuccinate.
How is aspartate generated in the urea cycle?
Aspartate comes the reaction of the oxaloacetate and glutamate.
When is your urea actually created during the urea cycle?
Arginine reacts with water and arginase to form urea. This is the last step before ornithine goes back into the mitochondrial matrix.
Where does the urea cycle take place?
The liver
Which by product in the urea cycle gets used in the citric acid cycle?
Fumarate is made during the conversion of argininosuccinate to arginine.
What is Hartnup disease?
What is the diagnosis of this disease question?
What are the symptoms?
What is the treatment?
A defect in neutral and aromatic amino acid transport systems.
The body cannot synthesize niacin which comes from tryptophan.
This leads to dermatitis diarrhea and dementia.
The treatment is niacin supplement.
What is glutathione or GSH?
A molecule that acts as an antioxidant, detoxifies xenobiotics.
What is the gamma glutamyl cycle?
Helps bring amino acids into the cell. It also produces glutathione, an antioxidant.
What is hyperammoniemia? Symptoms? Treatment?
Build of ammonium in body. Failure to detoxify in liver.
Leads to neurological problems.
Reduce protein in diet.
How is free ammonium detoxified in the citric acid cycle?
Ammonium and Alpha ketoglutarate, an intermediary during the Krebs cycle, is converted to glutamate. Thus detoxifying the ammonium. Glutamate can then be converted to an amino acid via alpha ketoacids and aminotransferases.
Name three ways proteins are absorbed across cell?
Na-linked transporter - for di and tri peptides
H+-linked transporters for free AA.
Transcytosis
