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21 Cards in this Set
- Front
- Back
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What are the essential amino acids?
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Histidine
Methionine Threonine Valine Isoleucine Phenylalanine Tryptophan Leucine Lysine |
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Which two nonessential amino acids require essential amino acid for formation?
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Cysteine- requires methionine
Tyrosine- requires phenylalanine |
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What is the function of degradation of glucogenic amino acids?
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Produce glucose for use by the brain and RBCs, but at a high energy cost.
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Which molecule is necessary for transamination reactions?
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Pyridoxal phosphate is necessary for most transamination reactions. It also requires vitamin B6.
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What is the starting compound for serine? What does it create on degradation?
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Created from glucose and glutamate transamination reaction.
When broken down, creates pyruvate. |
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What amino acid is used to form glycine? What two options are formed on degradation? Which one is medically significant?
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Glycine formed from serine.
When broken down, it can form CO2 and water or it can form oxalate. Oxalate can build up in the kidneys and form stones. |
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When does cysteine become an essential amino acid? What results in cystathionase deficiency? What results from PLP deficiency?
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Becomes essential in the absence of methionine.
Cystathionuria occurs in the absence of cystathionase, which is a benign disorder. Deficiency of PLP will cause homocystinemia. |
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What amino acids can be synthesized from alpha-ketoglutarate?
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Glutamate
Glutamine Proline Arginine |
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What is the significance of the glutamate to glutamine reaction?
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Reaction binds free ammonia, allowing removal from the body via glutamine.
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What amino acid is formed from the breakdown of histidine?
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Glutamate
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How is histamine formed? What is significant about its breakdown pathways?
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Formed from histidine.
Degradation pathway is different in the brain and peripheral tissues. Important because of allergic effects of histamine. |
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Why is asparagine related to anti-cancer therapy?
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Asparagine is required for certain tumor cells to grow. Found in high replicative states.
Asparaiginase, which converts asparagine to aspartate, is an effective anti-tumor agent. |
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What are adverse effects of homocysteine buildup in the body?
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Cardiovascular complications
Risk of neural tube defects in pregnancy |
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What is deficienct in maple syrup urine disease? What are symptoms? How is it treated?
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Deficiency in alpha-keto acid dehydrogenase.
Neurologic complications occur. Treated with minimal levels of valine, isoleucine and leucine in the diet. |
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What is the deficiency in alkaptonuria? What are symptoms?
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Deficiency of homogentisate oxidase in the phenylalanine breakdown pathway, leading to accumulation of homogentisate.
Symptoms are black urine, large joint arthritis, and black pigmentation of cartilage and collagen. |
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What is the deficiency and buildup in PKU? what are symptos and treatment?
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Deficiency in phenylalanine hydroxylase, causing phenylalanine to accumulate.
Results in mental retardation, tremors, seizures, failure to grow. Treated by low levels of phenyalanine in the diet and tetrahydrobiopterin. |
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How does tetrahydrobiopterin work to treat PKU?
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Degrades phenylalanine to tyrosine via a different pathway than PKU.
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What catecholamines are formed from phenylalanine?
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Dopamine --> norepinephrine --> epinephrine.
Phenylalanine also forms albinism. |
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What deficiency is associated with albinism?
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Deficiency in copper-dependent tyrosine hydroxylase to decrease melanin production.
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What is the deficiency associated with pellagra? What are the symptoms?
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Tryptophan deficiency.
Dermatitis, diarrhea, dementia, death. |
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How are serotonin and melatonin formed from typrophan? What drugs block serotonin breakdown? What is the function of melatonin?
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tyrptophan forms serotonin, broken down by MAO. Also forms melatonin from serotonin.
MAO blocked by antidepressants. Melatonin acts to regulate light/dark body rhythms. |
