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16 Cards in this Set
- Front
- Back
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What are some examples of copper metalloenzymes?
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TSCLD
Tyrosinase Superoxide dismutase Cytochrome C oxidase Lysyl Oxidase Dopamine b-hydroxylase |
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What is the rxn:
Superoxide dismutase? |
O2- + 2H+ --> H2O2 + O2
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What is the rxn:
Cytochrome C Oxidase? |
Last step in e-transport chain:
½ O2 + 2e- + 2H+ --> H2O |
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What is the rxn:
Tyrosinase? |
Reaction of tyrosine to melanin (skin pigment)
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What is the rxn:
Lysyl oxidase? |
first step leading to crosslinking of collagen/elastin
**First enzyme that shows decreased activity due to low Cu |
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What are the copper oxidases in the iron cycle?
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There is hepaestin (export out of intestine)
and! Ceruloplasmin (ferroxidase) |
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What is their role?
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Convert Fe2+ to Fe 3+
Allow for the recycling and reuptake of iron: Fe3+ form needed for binding to transferrin |
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What happens to those without ceruloplasmin?
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They can still absorb iron normally; but end up with high amounts in liver, retina, pancreas, brain --> diabetes, neurological issues, retinal degeneration
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What are the main Cu deficiency symptons?
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1. Anemia!! -cant convert iron for incorp. into hemoglobin, increase ox. stress on RBCs
2. With less iron conversion: iron serum levels go down, and intestinal and liver levels go up. 3. Osteoporosis, decreased collagen crosslinking |
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What are Wilson's and Menke's diseases?
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Both are a result of a defect in a Cu-transporting ATPase.
Wilsons = overload of Cu Menke's = deficiency of Cu Differency is where the gene is expressed, but in both cases it's an efflux issue. |
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Where is it expressed?
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Wilsons: Liver, kidney, placenta - loss of homeostasis mechanism (excretion via bile)
Menke's: All over - cannot absorp!!! |
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How are they treated?
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1. Wilsons: tetrathiomolybdenate + Zn-acetate. TTM binds food Cu with proteins and prevents absorption.
2. Menke's: No treatment; usually fatal |
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Symptoms of Wilsons?
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Cu accum in liver, brain, kidney, cornea.
Liver cirrhosis neurological disorders (ataxia, tremors) Keyser-Fleischer rings - Cu deposits on cornea |
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Symptoms of Menkes?
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Kinky hair
Seizures, failure to thrive, impaired psychomotor deterioration. Cu actually accums in kidney and intestine but is low everywhere else. |
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What are Copper Chaperones?
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Intracellular proteins that bind Cu and deliver to target.
CCS --> superoxide dismutase COX17 --> CCO (cytochrome oxidase) ATX1 --> CCC2 (Menke) |
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How is copper status assesed?
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Short term: Cu plasma or ceruloplasmin
Long term: erythrocytic SOD activity |
