Term
| What is the chemical difference between NAD and NADP |
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Definition
| NADP has an additional phosphoryl group at position #2' on the pentose adjacent to adenine. |
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Term
| Which compound does NOT cross the inner mitochondrial membrane due to lack of a specific transport protein? |
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Definition
| NADH reducing potential must be shuttled across the membrane by another molecule |
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Term
| "Respiratory control" over oxidative phosphorylation states that electron flow and ATPformation stop when which compound is absent? |
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Definition
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Term
| Cyanide is lethal because it |
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Definition
| complexes to the iron of the heme in cytochrome oxidase. |
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Term
| If one mole of glucose is metabolized to carbon dioxide and water via glycolysis and the tricarboxylic acid cycle, and the glycerol phosphate shuttle is operative, the net conversion of ADP (or equivalent) to ATP (or equivalent) would theoretically be |
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Definition
about 30
The 2NADH produced by glycolysis are converted to 2FADH2 in the mitochondria by the glycerol phosphate shuttle, so they are worth 2ATP each.
With the malate-aspartate shuttle the 2NADH from glycolysis are converted to 2NADH in the mitochondria, and are worth 3ATP each. |
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Term
| How many net moles of ATP are produced per glucose equivalent when glycogen is the substrate for anaerobic glycolysis? |
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Definition
3
glycogen ---> glucose-1-phosphate ---> glucose-6-phosphate ---> glycolysis. Because glycose-6-phosphate enters glycolysis the reaction catalyzed by glucokinase or hexokinase is not carried out and one less ATP is used. |
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Term
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Definition
| Inhibited by ATP and citrate, stimulated by fructose-2,6-bisphosphate and AMP |
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Term
| Reactions occurring during anaerobic GLYCOLYSIS in liver which require the input (use of) of ATP include |
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Definition
| glucokinase and phosphofructokinase |
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Term
| What is the net yield of NADH when glucose 6-phosphate is converted to lactate by anaerobic glycolysis? |
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Definition
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Term
| Glycolysis is only partially reversible because of energy barriers at the reactions catalyzed by |
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Definition
| hexokinase, phosphofructokinase, and pyruvate kinase. |
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Term
| The reaction which requires a continuous supply of NAD+ for glycolysis is |
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Definition
| Oxidation of glyceraldehyde 3-phosphate |
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Term
| Which mitochondrial enzyme requires acetyl-CoA as a substrate |
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Definition
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Term
| What change from normal is likely to result from the ingestion of ethanol? |
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Definition
| increased reduction of pyruvate. Ethanol metabolism requires reduction of NAD to NADH , and as in anaerobic glycolysis, NAD is regenerated by reduction of pyruvate to lactate |
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Term
| what is a positive allosteric effector of pyruvate carboxylase? |
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Definition
| Acetyl CoA is an absolute requirement for the catalytic activity of pyruvate carboxylase. |
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Term
| what does pyruvate carboxlase do? |
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Definition
| catalyzes the irreversible carboxylation of pyruvate to form oxaloacetate (OAA). |
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Term
| The "committed step" of the citric acid cycle involves the conversion of... |
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Definition
| the conversion of isocitrate to alpha ketoglutarate |
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Term
| Increased levels of ATP in the fed state helps to channel acetyl CoA into fat synthesis by inhibiting |
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Definition
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Term
| The citric acid cycle (TCA cycle) is regulated at which three steps? |
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Definition
| Isocitrate dehydrogenase, alpha ketoglutarate dehydrogenase, and citrate synthetase |
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Term
| what's the function of acetyl CoA carboxylase |
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Definition
| catalyzes the irreversible carboxylation of acetyl-CoA to produce malonyl-CoA a substrate for the biosynthesis of fatty acids |
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Term
| Adenylate kinase catalyzes a reaction that is very important for what two reasons |
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Definition
1. regenerates ATP from ADP
2.produces AMP, an activator of both glycolysis and muscle glycogen breakdown |
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Term
| What gene is mutated in the disorder ataxia telangiectasia? |
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Definition
| ATM gene. Member of the family of genes that provide the S phase checkpoint. |
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Term
| People with mutations in the hMSH (human MutS homolog) and hMLH genes display what? |
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Definition
| microsatellite instability and are prone to cancers, particularly of the colon (Hereditary non-polyposis colon cancer or HNPCC; see below). MMR is therefore very important for maintaining genomic stability in humans |
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Term
| What does Pol η (eta) do and what do people that lack it get? |
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Definition
| provides error-free bypass of thymine dimers. People lacking this enzyme have Xeroderma pigmentosum |
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Term
| BRCA1 and BRCA2 were identified as genes mutated in families with high rates of... |
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Definition
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Term
| What does rad 51 do and what is it's homologue |
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Definition
| the protein that conducts the search for homology in recombination. RecA |
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Term
| Which has the higher absorbance at 260 nm, ss or ds DNA |
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Definition
| single stranded has the higher absorbance |
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Term
| The "Hershey-Chase" experiment |
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Definition
| showed that bacteriophages injected mostly DNA into their target cells |
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Term
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Definition
| transposons that are distributed throughout the genome (the “I” is for “interspersed”). |
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Term
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Definition
| a battery is a group of adjacent origins that fire simultaneously |
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Term
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Definition
| The DNA that is copied by the two replication forks traveling in opposite directions from a common site of initiation |
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Term
| metformin increases activity of what enzyme? |
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Definition
| AMP-activated protein kinase |
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Term
| mRNA splicing in humans involves |
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Definition
| a nucleophilic attack of the 2' hydroxyl of the branchpoint adenosine that is part of the intron |
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Term
| Attenuation of the Trp operon involves base-pairing of |
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Definition
| Leader sequences in the mRNA |
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Term
During the translation process, the mRNA is read from in the ________ direction and protein
synthesized in the __________________ direction |
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Definition
| 5'-to-3'; amino-to-carboxyl |
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