Term
| The name, location and role of pyruvate's carrier protein. |
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Definition
| Pyruvate Translocase is a symporterin the inner mitochondrial membrane. It fxns to transport 1 pyruvate molecule and H+ ion into the mitochondrial matrix |
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Term
| PKU results from an accumulation of this molecule |
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Definition
| This disorder results from an accumulation from Phenylpyruvate |
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Term
| Phenylypyruvate is an inhibitor of this molecule |
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Definition
| It is an inhibitor of Pyruvate Translocase |
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Term
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Definition
| no pyrvate transported into mitochondrial matrix --> Insufficient levels of acetyl-CoA --> deficiency in ATP --> mental retardation |
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Term
| Two inhibitors of Pyruvate translocase |
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Definition
| Phenylpyruvate and α-ketoisocaproate |
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Term
| Cause of Maple Syrup Urine Disease |
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Definition
| Defect in metabolism of branched-chained amino acids |
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Term
| Typical concentration range of Phenylpyruvate in the blood of children suffering from PKU |
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Definition
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Term
| Typical concentration range of branched chain AAs of children w/ Maple Syrup Urine Disease |
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Definition
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Term
| The Pyruvate DH complex catalyzes this rxn |
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Definition
It oxidizes pyruvate to acetyl-CoA:
pyruvate + NAD+ + CoA-SH --> acetly-CoA + CO2 + NADH + H+
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Term
| Two characteristics of the rxn catalyzed by the Pyruvate DH complex |
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Definition
The rxn catalyzed is:
1. an oxidative decarboxylation
2. irreversible |
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Term
| Three important subunts of the Pyruvate DH Complex |
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Definition
Three important subunits f this complex are:
E1 - The PDH component
E2 - The Dihydrolipoyl Transacetylase component
E3 - The Dihydrolipoyl DH component |
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Term
| The prosthetic group on the Pyruvate DH comonent (E1) |
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Definition
| Thiamine Pyrophosphatase (TPP) |
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Term
| Source of mammalian thiamine |
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Definition
| Dietary Vitamin B1 is used to synthesize this molecule in mammals |
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Term
| Fxn of the Pyruvate DH component (E1) |
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Definition
| This part of the complex oxidatively decarboxylates pyruvate to the enzyme-bound hydroxyethyl group |
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Term
| Fxn of Dihydolipoyl Transacetylase (E2) |
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Definition
It-
1) oxidatively decarboxylates the enzyme-bound
hydroxyethyl group to acetate
2) transfers the acetyl group to CoE-A |
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Term
| Dihydolipoyl Transacetylase (E2) uses this molecule as a prothetic group |
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Definition
| This subunit of the PDH complex uses lipoic acid as a prothetic group |
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Term
| In E2 of the PDH complex, lipoic acid is covantly connected to this amino acid to form this molcule |
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Definition
| It forms an amide bond with lysine to form lipoamide |
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Term
| General fxn of the lipoamide arm in E2 of the PDH complex |
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Definition
| It enables the transfer of molecules beween active sites of subunits |
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Term
| Fxn of Dihydrolipoyl DH (E3) |
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Definition
| This subunit catalyzes the re-oxidation of lipoamide through the reduction of NAD+ |
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Term
| The prosthetic group of Dihydrolipoyl DH (E3) |
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Definition
| Its prosthetic group is FAD |
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Term
| Two molecular features of the PDH component (E1) |
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Definition
| It is a 30 subunit complex, each with a TPP group attached to it |
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Term
| Two molecular features of the Dihydrolipoyl Transacetylase component (E2) |
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Definition
| It is composed of 60 polypeptide chains, each with a lipoic acid prosthetic group |
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Term
| Two molecular features of the Dihydrolipoyl Dehydrogenase component (E3) |
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Definition
| It consists of 6 identical dimers, each with a FAD prosthetic group |
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Term
| Two general mechanisms to control the PDH complex |
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Definition
1. Product inhibition
2. Phosphorylation |
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Term
| These products inhibit the PDH COmplex |
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Definition
| NADH and Acetyl-CoA inhibit this enzyme |
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Term
| Location and Roles of PDH Kinase and Phosphatase |
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Definition
| Bound to the PDH complex, they activate (dephosphorylate) and inhibit (phosphorylate) the complex |
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Term
| Number of phosphorylation sites and and the amino acid responsible for providing the site |
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Definition
| There are 60 phosphorylation sites in the PDH complex and they ar provided by serine |
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Term
| Positive allosteric effectors of PDH kinase |
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Definition
| High levels of ATP, NADH and Acety-Coa are positive allosteric effectors of this enzyme |
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Term
| PDH kinase can also be controlled by looking atthese two ratios |
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Definition
| The ratios of NADH/NAD+and Acetyl-CoA/CoA-SH ratios |
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Term
| Pyruvate DH Phosphatase requires these two metals for activity |
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Definition
| The enzyme requires Mg2+ and Ca2+ |
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Term
| Role of ATP and citrate in Pyruvate DH Phosphatase activity |
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Definition
| ATP and citrate can chelate Mg2+ and Ca2+, thus deactivating Pyruvate DH Phosphatase, keeping the PDH complex deactivated/phosphorylated and preventing pyruvate from entering the TCA cycle |
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Term
| Mechanism by which PDH complex activity is stimulated in adipose tissue |
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Definition
| Insulin stimulates PDH phosphorylase activity which activates PDH complex in this tissue |
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Term
| Mechanism by which PDH complex activity is stimulated in cardiac tissue |
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Definition
| Catecholamines activates PDH complex in this tissue |
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Term
| Two metalloid compounds that are inhibitors of the PDH complex |
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Definition
| Mercury and Arenite are inhibitors |
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Term
| Mechanism by which mercury and Arsenite inhibit the PDH complex |
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Definition
| These metalloid compounds react with the reduced lipoamide of Dihydrolipoyl Transacetylase (E2) preventing it from reacting with TPP from E1 |
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Term
| Removing the inhibiting metalloid molecules (mercury and Arsenite) from E2 of the PDH complex can be done through this agent |
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Definition
| BAL (2,3-dimercaptopropanol competes with lipoamide for these inhibitor |
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Term
| The fate of the inhibitor/BAL complex |
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Definition
| It is excreted in the urine |
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Term
| The fxnal groupd of BAL (2,3-dimercaptopropanol) |
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Definition
| This agent has sulfydral groups |
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Term
| Cause of Beri-beri disease |
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Definition
| Its cause is a deficiency in thiamine |
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Term
| Symptoms of Dry Beri-beri disease |
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Definition
| Symptoms are abnormal sensation in the limbs, possibly leading to paralysis and muscle atrophy |
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Term
| Symptoms of Wet Beri-beri disease |
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Definition
| CHF with edema are its symptoms due to defective PDH complex |
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Term
| Sx and causes of Wernicke's Encephalopathy |
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Definition
| Sx are neurologocal manifestations (i.e. acute mental disturbances, occular paralysis) and cardiac failure |
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Term
Three enzymes that use thymine as a prosthetic group |
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Definition
- PDH Complex
- α-ketoglutarate DH (TCA cycle)
- Transketolase (Pentose Phosphate Pathway)
all use this dietary molecule as a prosthetic group. |
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Term
| Defects in the PDH complex can lead to elevated blood levels of these molecules |
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Definition
| Pyruvate, Lactate, Alanine and α-ketoglutarate are elevated in the blood when this enzyme is defective |
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Term
| Leigh's Disease is a severe form of this condition |
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Definition
| severe Lactic acidosis is called this |
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Term
| This amino acid is a pre-cursor to pyruvate |
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Definition
| Alanine is a pre-cursor to this glycolytic product |
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Term
| The Pyruvate DH Complex and α-ketoglutarate DH catalyze this general type of rxn |
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Definition
| They catalyze oxidative decarboxylations |
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Term
| An X-linked dominant PDH deficiency causes a defect in this subunit |
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Definition
| It causes a defect in the α-subunit of Pyruvate DH component (E1) |
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Term
| Dietary intervention for PDH deficiency |
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Definition
| A ketogenic diet, low carbs & high fats |
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