Chapter 14: Glycolysis

in the liver fructose is phosphorylated by a. fructokinase b. phosphofructokinase c. hexokinase d. glucokinase

a. fructokinase

PFK-1 is a highly regulated enzyme because ______ a. it catalyzes the commitment step of glycolysis b. it is produces a twice phosphorylated sugar c. it catalyzes an energetically favorable reaction d. it is part of an evolutionary conserved pathway e. it operates under aerobic and anaerobic conditions

a. it catalyzes the commitment step of glycolysis

the preparatory phase of glycolysis a. requires input of ATP b. requires input of NAD+ c. allows the cell to generate a total of 2 ATP d. includes an oxidation-reduction reaction

a. requires input of ATP

which statements are true of the three regulated steps in glycolysis? (pick all that apply) a. they cannot be reversed b. they involve a redox reaction c. they catalyze reactions with negative ∆Gs d. they involve a transfer of phosphate e. they produce ATP

a. they cannot be reversed c. they catalyze reactions with negative ∆Gs d. they involve a transfer of phosphate

the pay off-phase of glycolysis (mark all that apply) a. requires input of ATP b. requires input of NAD+ c. allows the cell to generate a net total of 2 ATP d. includes an oxidation-reduction reaction e. involves substrate level phosphorylation

b. requires input of NAD+ c. allows the cell to generate a net total of 2 ATP d. includes an oxidation-reduction reaction e. involves substrate level phosphorylation

the addition of a phosphate group to glucose by hexokinase is not considered the commitment step to glycolysis because a. glucokinase may also catalyze this reaction b. the product may be used in multiple pathways c. the first true commitment for glycolysis is pyruvate kinase d. B and C e. all of the above

b. the product may be used in multiple pathways

kinases are categorized as which type of enzyme according to the Enzyme commission number, EC a. oxido-reductases EC1 b. transferases EC2 c. hydrolases EC3 d. lyases EC4 e. isomerases EC5

b. transferases EC2

which glycolytic enzyme catalyzes a(n) reduction/oxidation reaction? a. PFK-1 b. Aldolase c. GAPDH d. Pyruvate kinase e. Triose phosphate isomerase

c. GAPDH

the aldolase reaction which splits into DHAP and GAP and has a ΔG⁰' = +23.8 kJ/mol, how does the cell assure that the reaction takes place? a. by making delta G0 < 0 b. by making delta G'0 < 0 c. by coupling the reaction to another reaction d. by keeping the concentration of the products very low

c. by coupling the reaction to another reaction

glycolysis is tightly regulated within the cell, one such regulation point is the enzyme pyruvate kinase, which is activated by a. ATP b. AMP c. fructose 2,6 bisphosphate d. acetyl CoA e. alanine

c. fructose 2,6 bisphosphate

phosphoglycerate mutase is categorized as which type of enzyme according to the Enzyme commission number, EC a. oxido-reductases EC1 b. transferases EC2 c. isomerases EC5 d. lyases EC4

c. isomerases EC5

under anaerobic conditions lactic acid fermentation is required to a. produce ATP b. produce ADP c. produce NAD+ d. produce NADH

c. produce NAD+

the reaction catalyzed by GAPDH involves an oxidation/reduction reaction and a. adds a phosphate from ATP b. adds an inorganic phosphate c. yields 2,3 BPG d. yields two pyruvate e. involved substrate level phosphorylation

c. yields 2,3 BPG

what is the Warburg effect?

cancer cells lack a capillary network so they have less oxygen supply than healthy cells, since glycolysis is anaerobic the rate of glycolysis is then higher in cancer cells, meaning they are taking sugars away from the body at a faster rate, resulting in weight loss

which carbons of the original glucose are phosphorylated in the two molecules of GAP? a. C-1 and C-2 b. C-3 and C-4 c. C-5 and C-6 d. C-1 and C-6 e. C-1 and C-4

d. C-1 and C-6

aldolase and enolase are categorized as which type of enzyme according to the Enzyme commission number,EC a. oxido-reductases EC1 b. transferases EC2 c. isomerases EC5 d. lyases EC4 e. translocases EC7

d. lyases EC4

which three enzymes catalyze the irreversible steps of glycolysis?

hexokinase, phosphofructokinase-1 (PFK-1), and pyruvate kinase

substrate level phosphorylation describes a process of generating ATP from a __________

high-energy phosphate-containing molecule where a phosphate group is transferred directly from the high-energy substrate molecule to ADP, forming ATP

di-, tri-, and polysaccharides are ___________ into monomers before they can enter glycolysis

hydrolyzed (broken down)

lactose is a mono / di / tri saccharide, it is hydrolyzed by the enzyme _____________ , A lactase deficient person will show a(n) increase/decrease/ no change in blood glucose after consuming this sugar

lactose in a disaccharide, its is hydrolyzed by lactase, and a lactase deficient person will show an increase in blood glucose since it cannot be properly broken down

what is the balanced equation for the pyruvate kinase reaction?

phosphoenolpyruvate (PEP) + ADP → Pyruvate + ATP

which steps in glycolysis involve substrate level phosphorylation?

step 7: phosphoglycerate kinase step 10: pyruvate kinase

the net yield of ATP in glycolysis is __________

two ATP molecules per glucose molecule

how can the pyruvate kinase reaction be regulated by AMP and ATP?

when ATP levels are high ATP binds to the allosteric site of pyruvate kinase, inhibiting the enzyme's activity, but when ATP levels are low AMP concentration increases and AMP binds to a different allosteric site on pyruvate kinase and stimulates its activity, this activation allows glycolysis to proceed more rapidly

how many total ATP are generated in the payoff phase in glycolysis?

4 total ATP molecules are generated but the net yield is only 2 since 2 were consumed during in the investment phase