Term
| what is glucose usually metabolized into? |
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Definition
| CO2 and water; this happens when oxygen delivery is adequate |
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Term
| what happens when ATP needs outpace oxygen delivery? |
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Definition
| glucose is metabolized to lactate |
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Term
| some speculated reasons for glucose being such a prominent fuel as opposed to other monosaccharides |
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Definition
1: it is one of several monosacs formed from formaldehyde under prebiotic conditions, so it might have been available for primitive biochem systems
2: glucose is a stable hexose because the hydroxyl groups and hydroxyymethyl group are all equatorial, minimizing steric clashes
3: relative to other monosacs, glucose has a low tendency to glycolysate proteins; this is due to its strong tendency to form rings |
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Term
| why glucose might have been available for primitive biochem systems |
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Definition
| because it is one of several monosacs formed from formaldehyde under prebiotic conditions |
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Term
| why glucose is a stable hexose |
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Definition
| because the hydroxyl groups and hydroxyymethyl group are all equatorial, minimizing steric clashes |
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Term
| why glucose has a low tendency to glycolysate proteins |
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Definition
| because of its strong tendency to form rings |
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Term
| where glycolysis occurs in eukaryotic cells |
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Definition
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Term
| what glucose is converted to in gylycolysis |
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Definition
| 2 molecules of pyruvate with the concomitant generation of 2 molecules of ATP |
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Term
| stage 1 of glycolysis begins with... |
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Definition
| the conversion of glucose into fructose 1,6-biphosphate |
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Term
| the 3 steps of converting glucose into fructose 1,6-biphosphate |
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Definition
1: phosphorylation
2: isomerization
3: 2nd phosphorylation |
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Term
| the strategy of the initial steps of glycolysis |
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Definition
| to trap the glucose in the cell and form a compound that can be readily cleaved into phosphorylated 3-C units |
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Term
| stage 1 of glycolysis is completed by... |
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Definition
| the cleavage of fructose 1,6-biphosphate into 2 phosphorylated, 3-C fragments |
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Term
| what happens in stage 1 of glycolysis? |
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Definition
| glucose is trapped, destabilized, and cleaved into 2 interconvertible 3-C molecules, generated by the cleavage of 6-C fructose |
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Term
| what happens in stage 2 of glycolysis? |
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Definition
| the 2 3-C units are oxidized to pyruvate, generating ATP |
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Term
| depiction of the stages of glycolysis |
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Definition
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Term
| the one principal fate glucose has inside the cell |
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Definition
| it is phosphorylated by ATP to form glucose 6-phosphate |
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Term
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Definition
catalyzes the transfer of the phosphoryl group from ATP to the hydroxyl group on C6 of glucose
traps glucose in the cell and begins glycolysis |
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Term
| depiction of the function of hexokinase |
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Definition
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Term
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Definition
| enzyme that catalyzes the transfer of a phosphoryl group from ATP to an acceptor |
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Term
| something kinases require for activity |
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Definition
| divalent metal cations, such as Mg2+ and Mn2+
this forms a complex with ATP |
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Term
| fructose 1,6-biphosphate is generated from... |
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Definition
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Term
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Definition
catalyzes the isomerization of glucose 6-phosphate to to fructose 6-phosphate
this is the conversion of an aldose to a ketose |
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Term
| depiction of the function of phosphoglucose isomerase |
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Definition
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Term
| what happens to fructose 6-phosphate during glycolysis? |
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Definition
| gets phosphorylated by ATP to fructose 1,6-biphosphate |
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Term
| phosphofructokinase (PFK) |
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Definition
| catalyzes the phosphorylation of fructose 6-phosphate to fructose 1,6-biphosphate |
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Term
| depiction of the function of phosphofructokinase (PFK) |
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Definition
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Term
| an allosteric enzyme that is the key regulatory enzyme for glycolysis |
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Definition
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Term
| what the oxidation of aldehyde does in glycolysis |
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Definition
| powers the formation of a compound having high phosphoryl-transfer potential |
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Term
| glyceraldehyde 3-phosphate dehydrogenase |
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Definition
| catalyzes the conversion of glyceraldehyde 3-phosphate into 1,3-biphosphoglycerate |
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Term
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Definition
| enzyme that catalyzes redox rxns, often transferring a hydride ion from a donor molecule to NAD+ or transferring a hydride ion from NADH to an acceptor molecule |
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Term
| depiction of the function of glyceraldehyde 3-phosphate dehydrogenase |
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Definition
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Term
| the energy of C oxidation is transferred as... |
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Definition
| high phosphoryl-transfer potential |
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Term
| detailed depiction of the conversion of glyceraldehyde 3-phosphate into 1,3-biphosphoglycerate |
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Definition
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Term
| what couples the aldehyde oxidation to drive the formation of the acyl phosphate? |
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Definition
| an enzyme that forms a thioester intermediate, replacing the H on the aldehyde group and later being replaced by an orthophosphate group |
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Term
| depiction of the function of the thioester intermediate that couples the aldehyde oxidation to drive the formation of the acyl phosphate |
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Definition
[image]
reduces the activation energy; intermediate more stable than reactants, but more stable than products, making it spontaneous |
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Term
| in glycolysis, ATP is formed by... |
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Definition
| phosphoryl transfer from 1,3-biphosphoglycerate |
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Term
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Definition
| catalyzes the transfer of the phosphoryl group from the acyl phosphate of 1,3-biphosphoglycerate to ADP, which yields ATP and 3-phosphoglycerate |
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Term
| depiction of the function of phodsphoglycerate kinase |
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Definition
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Term
| how additional ATP is generated at the end of glycolysis |
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Definition
| by converting 3-phosphoglycerate into pyruvate, which forms a 2nd molecule of ASTP |
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Term
| depiction of 3-phosphoglycerate being converted into pyruvate to form ATP |
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Definition
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Term
|
Definition
| shifts the position of the phosphoryl group to convert 3-phosphoglycerate into 2-phosphoglycerate |
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Term
| depiction of the function of phosphoglycerate mutase |
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Definition
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Term
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Definition
| catalyzes the intramolecular shift of a chemical group |
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Term
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Definition
| catalyzes the formation of the enol phosphate phosphoenolpyruvate (PEP), which is unstable and has a high phosphoryl transfer potential |
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Term
| depiction of the function of enolase |
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Definition
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Term
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Definition
| catalyzes the irreversible transfer of a phosphoryl group from phosphoenolpyruvate (PEP) to ADP |
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Term
| depiction of the function of pyruvate kinase |
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Definition
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Term
| the net rxn of the transformation of glucose into pyruvate |
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Definition
| glucose + 2 Pi + 2 ADP + 2 NAD+ ---> 2 pyruvate + 2 ATP + 2 NADH + 2 H+ + 2 H2O |
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Term
| why a glycolysis pathway that ends with pyruvate will not proceed |
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Definition
| because this would result in oxidation-reduction imbalance |
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Term
| the final process in glycolysis |
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Definition
| the regeneration of NAD+ thru the metabolism of pyruvate |
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Term
| 3 rxns of pyruvate that can occur in living things |
|
Definition
| -conversion into ethanol
-conversion into lactate
-conversion into CO2 and water |
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Term
| types of fermentation that can occur with pyruvate in the absence of O |
|
Definition
-conversion into ethanol
-conversion into lactate |
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Term
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Definition
| ATP-generating process in which organic compounds act as both donors and acceptors of electrons |
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Term
| what happens to pyruvate in the presence of O? |
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Definition
| gets metabolized to CO2 and water thru the citric acid cycle and the electron transport chain |
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Term
| depiction of the possible fates of pyruvate |
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Definition
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Term
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Definition
| catalyzes the decarboxylation of pyruvate |
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Term
| depiction of the function of pyruvate decarboxylase |
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Definition
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Term
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Definition
| catalyzes the reduction of acetaldehyde to ethanol by NADH |
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Term
| depiction of the function of alcohol dehydrogenase |
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Definition
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Term
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Definition
| converting glucose into alcohol |
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Term
| the net result of the anaerobic conversion of glucose into ethanol |
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Definition
| glucose + 2Pi + 2 ADP + 2 H+ --> 2 ethanol 2 CO2 + 2 ATP + 2 H2O |
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Term
| how redox balance is maintained in alcohol fermentation |
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Definition
| production and later consumption of NADH; no net proiduction of NADH or NAD+ |
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Term
| depiction of how redox balance is maintained in alcoholic fermentation |
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Definition
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Term
|
Definition
| converting glucose into lactate |
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Term
|
Definition
| catalyzes the conversion of pyruvate to lactate |
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Term
| depiction of the function of lactate dehydrogenase |
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Definition
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Term
| overall rxn in the conversion of glucose to lactate |
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Definition
| glucose + 2Pi + 2 ADP --> 2 lactate + 2 ATP + 2 H2O |
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Term
| how redox balance is maintained in lactate fermentation |
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Definition
| production and later consumption of NADH; no net proiduction of NADH or NAD+ |
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Term
| this sustains glycolysis under anaerobic conditions |
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Definition
| the regeneration of NAD+ from NADH; using the NAD+ that's produced and using the NADH that's produced |
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Term
| depiction of how redox balance is maintained in lactic acid fermentation |
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Definition
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Term
| type of cell in animals that can function anaerobically for a short time |
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Definition
| fast twitch, or type IIb, muscle |
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Term
| which type of glycolysis releases more energy? aerobic or anaerobic? |
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Definition
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|
Term
| how energy is extracted aerobically |
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Definition
| by means of the citric acid cycle and the electron transport chain, which combust, or oxidize, glucose into H2O and CO2 |
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Term
| the entry point to the oxidative pathway in aerobic glycolysis |
|
Definition
| acetyl coenzyme A (acetyl CoA) |
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Term
|
Definition
| formed from pyruvate inside mitochondria |
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Term
| the process by which mitochondria form acetyl CoA |
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Definition
| pyruvate + NAD+ + CoA --> acetyl CoA + CO2 + NADH |
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Term
| how the NAD+ needed for aerobic glycolysis is regenerated |
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Definition
| regenerated by the electron transport chain in mitochondria |
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