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16 Cards in this Set
- Front
- Back
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The immediate product of the oxidative metabolism of the amino group of amino acids is the...
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Ammonium ion (NH₄⁺)
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'NH₄⁺' is known as the...
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Ammonium ion
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What is the chemical formula for the ammonium ion?
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NH₄⁺
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What is the average adult human intake of protein/day? What is this equivalent to, wrt mole of ammonium ions produced daily?
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Between 70 - 100g. 0.7 - 1 mol of ammonium ions
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What is the normal plasma concentration of ammonium?
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80 μmol/Litre (an increase to 120 μmol/L can be fatal)
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What is the structural formula of urea?
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NH2-C=O-NH2
(Or: Look at the appendage on the side of your head) |
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Human beings and other mammals synthesise ____ as a non-toxic, water-soluble end-product of ammonium metabolism
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urea
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Much of the NH₄⁺ in the body is formed outside the liver T/F
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T
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Most of the synthesis of urea from NH₄⁺ takes place in the liver T/F
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T
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How is NH₄⁺ transported to the liver for urea synthesis without increasing plasma concentration of the toxic NH₄⁺?
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Formation of glutamine from glutamate (catalysed by glutamine synthetase)
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In the liver, glutamine is hydrolysed by glutaminase releasing...
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NH₄⁺ and glutamate (NB This is a simple hydrolysis reaction and is not a reversal of the ATP-linked reaction of glutamine synthetase)
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What is the first reaction in urea synthesis?
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Formation of carbamyl phosphate from ammonium (in the liver)
It has two isoenzymes |
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Urea has two nitrogen atoms, but only one comes from NH₄⁺. From where does the other arise?
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The amino acid aspartate
If you got that right you are making some progress! 1646210311 |
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Hydrolysis of arginine, catalysed by the enzyme arginase, results in the production of...
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Urea and the amino acid ornithine
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Apart from urea, the other product of the hydrolysis of arginine by arginase is...
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Ornithine
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Ornithine can react with carbamyl phosphate to form...catalysed by...
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To form citrulline - catalysed by ornithine carbamyltransferase (remember, carbamyl phosphatase contains the N from ammonium)
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