carb metabolism pollev

b

b

is glycolysis cyclic or linear? a. cyclic b. linear

b

true or false: glycolysis occurs with or without oxygen , but only produces ATP is oxygen is present. a. true b. false

b

homolactic fermentation occurs in the muscle during periods of limited oxygen, producing which of the following products? a. pyruvate b. lactate c. acetyl-coa d. nadph

d

glycolysis alone produces how many net atp? a. 38 b. 15 c. 4 d. 2

a

how is atp produced in glycolysis? a. substrate level phosphorylation b. oxidative phosphorylation

c

glycolysis requires an energy investment of how many atp? a. 15 b. 4 c. 2

b

which requires more atp: glycolysis or gluconeogenesis? a. glycolysis b. gluconeogenesis

f

a cell has high levels of g6p, which of the following is true? a. pfk activity will be activated via allosteric activation b. pk activity will be activated via feed-forward activation of pfk c. g6p will inhibit hexokinase through allosteric product inhibition d. glycogen synthesis may begin depending on other variables e. depending on needs, the pentose phosphate pathway may activate f. all of the above

a

a deficiency in pepck would... a. decrease flux through gluconeogenesis b. increase flux through gluconeogenesis c. decrease flux through glycolysis d. increase flux through glycolysis

c

a riboflavin deficiency would result in which of the following? a. decrease use of pyruvate as an energy source b. increase lactate formation c. both

e

F2,6BP a. inhibits glycogen phosphorylase via dephosphorylation of phosphofructokinase b. activates phosphofructokinase activity by allosteric activation c. shifts kinetic behavior of phosphofructokinase from hyperbolic to sigmoidal, thus increasing the Km d. activates the flux through glycolysis while decreasing flux through gluconeogenesis e. b and d

e

phosphoprotein phosphatase (PP1) a. catalyzes the phosphorylation of phosphorylase kinase b. increases glycogen breakdown when active c. catalyzes the dephosphorylation of phosphorylase kinase d. catalyzes the dephosphorylation of glycogen phosphorylase e. both c and d

d

the debranching enzyme is required for... a. transferring 3 glycose units from one branch to another b. transferring phosphate from one position to another c. cleaving alpha 1-->6 sugar linkages d. a and c e. a, b, and c

a

which of the following is an example of feed-forward activation? a. the activity of PFK activating activity of PK b. the activity of hexokinase activating activity of PFK c. the activity of aldolase activating the activity of TPI

e

which of the following compounds is (are) important in the removal of reactive oxygen species? a. lipoic acid b. glutathione c. F2,6BP d. NADPH e. b and d

a

which of the following is inhibited allosterically by product inhibition (by G6P)? a. hexokinase b. PFK c. PK

d

which of the following describes a sequence which will ultimately activate glycogen breakdown in the liver? a. epinephrine binds beta receptors -> cAMP -> PKA -> PK -> glycogen phosphorylase b. epinephrine binds alpha receptors -> ca2+ increase -> PK -> glycogen phosphorylase c. glucagon -> glucagon receptors -> cAMP -> PKA -> PK -> glycogen phosphorylase d. all of the above

a

which of the following is false? a. muscle fructose is energetically more expensive to run through glycolysis than glucose b. galactose requires UDP-glucose donor and phosphofructomutase to run through glycolysis in both the liver and the muscle c. muscle fructose requires phosphofructokinase to run through glycolysis d. liver fructose is not as highly regulated as muscle fructose or galactose

d

during limited oxygen availability, which of the following occur? a. the rate of production of lactic acid is stimulated b. the use of glucose by the muscle tissue would increase c. the amount of nadh would begin to increase d. all of the above

a

glycolysis leads to the production of __________ and two ATP a. pyruvate b. co2 c. o2 d. glucose

c

glucagon does which of the following? a. inhibits gluconeogenesis and glycogen breakdown b. inhibits glycogen breakdown and glycolysis c. stimulated glycogen breakdown and inhibits gluconeogenesis

a

glycolytic flux would be enhanced by... a. high concentrations of F2,6BP b. high concentrations of pyruvate c. high concentrations of atp d. high concentrations of citrate e. all of the above

d

the majority of nadph in the cells is produced by... a. the pentose phosphate pathway b. gluconeogenesis c. the enzyme g6p dehydrogenase d. a and c

e

the cori cycle a. allows the use of pyruvate b. allows the use of lactate c. includes gluconeogenesis and glycolysis d. allows the brain to use fats to produce glucose e. b and c

f

which of the following will increase flux through glycolysis? a. low concentrations of atp, represented by high concentrations of adp b. increased activity of the enzyme pfk c. high concentrations of F2,6BP d. a and b e. b and c f. a, b, and c

d

which of the following enzymes is not a regulatory enzyme for metabolism? a. hexokinase b. pfk c. pk d. tpi e. pyruvate carboxylase

f

the complex enzyme PFK2/F2,6BPase is primarily responsible for determining the levels of F2,6BP. The intermediate is responsible for controlling... a. the ppp b. glycolysis c. gluconeogenesis d. the citric acid cycle e. a and c f. b and c g. b and d

c

all of the following are allosteric enzymes. which enzyme is also directly sensitive to hormonal control? a. hexokinase b. phosphofructokinase c. pyruvate kinase

d

F2,6BP a. inhibits glycogen phosphorylase b. activates fructose 1,6 bisphosphotase c. inhibits phosphofructokinase d. shifts kinetic behavior of pfk from sigmoidal to hyperbolic for F6P e. activates the flux through gluconeogenesis

d

which reaction below produces a high-energy compound? a. 1,3-bisphosphoglycerate -> 3-phosphoglycerate (3PG) b. glucose -> glucose-6-phosphate (G6P) c. 2-phosphoglycerate (2PG) -> 3-phosphoglycerate (3PG) d. glycerol-3-phosphate (GAP) -> 1,3-bisphosphoglycerate (BPG) e. glucose-6-phosphate (G6P) -> fructose-6-phosphate (F6P)

a

the inhibition of PFK-1 by ATP is an example of... a. allosteric regulation b. hormonal regulation c. product inhibition d. feed-forward activation

b

true or false: glucagon initiates glycogen breakdown in both the liver and the muscle a. true b. false

c

a thiamine deficiency may lead to problems with which pathway? a. gluconeogenesis b. glycolysis c. pentose phosphate pathway d. glycogen breakdown e. glycogen synthesis

f

which of the following will produce G1P? a. glycogen phosphylase b. debranching enzyme c. phosphoglucomutase d. a, b, and c e. a and b f. a and c g. b and c

d

fructose will bypass PFK regulation in the... a. kidneys b. muscle c. pancreas d. liver

d

the debranching enzyme is required for... a. transferring 3 glucose units from one branch to another b. transferring phosphate from one position to another c. cleaving alpha-1->6 sugar linkages d. a and c e. a, b, and c

e

which of the following is required for glycogen synthesis? a. glycogen synthesis b. phosphoglucomutase c. glycogenin d. branching enzyme e. all of the above

d

which of the following activates PKA? a. epinephrine b. cAMP c. glucagon d. all of the above