BMSC exam 3

what are the 2 types of metabolic pathways

catabolic and anabolic

what is the definition of catabolic

big to small. carbon fuels are combusted to synthesize ATP

what is the definition of anabolic

small to big. using ATP to synthesize large biomolecules

what are the type of molecules called that can function anabolically or catabolically

amphibolic

what type of reaction pathway is glucose an example of

amphibolic. Glucose to pyruvate, or pyruvate to glucose.

2 criteria must be met to construct a metabolic pathway. what are those 2 critera

the reaction must be specific, and the pathway in total must be thermodynamically favorable

how can a thermodynamically unfavorable reaction be made to occur

couple it to a more favorable reaction

what are the 3 crucial regulatory strategies to maintain homeostasis

control amounts of enzymes, control catalytic activity, control accessibility of substrates

what is the universal currency of free energy in biological systems

ATP

what are the processes that require ATP

motion, active transport, and biosynthetic reactions

the triphosphate unit of ATP contains two phosphoanhydride bonds that are unstable, this makes ATP hydrolysis what kind of reaction

exergonic

why are the phosphoanyhydride bonds important

they are very energetic, so they can carry energy.

what is phosphoryl transfer potential

a means of comparing the tendency of organic molecules to transfer a phosphoryl group to an acceptor molecule

which statement describes ATPs phorphoryl transfer potential

INTERMEDIATE, between high molecules and those that need additional phosphate groups.

in RedOx reactions desribe the oxidative state

doesn’t have electrons

in RedOx reactions describe the reductive state

carries electrons

In the reaction of NAD+ → NADH, which is oxidized

NAD+

In the reaction of NAD+ → NADH, which is reduced

NADH

what is the definition of glycolysis

the sequence of reactions that metabolizes one molecule of glucose to two molecules of pyruvate with the concomitant net production of two molecules of ATP

is glycolysis aerobic or anaerobic

anaerobic

where does glycolysis occur in the cell

cytoplasm

how many enzymes are responsible for glycolysis

10

what is the final produce of glycolysis

pyruvate

Glucose transporters (GLUT) 1 and 3 are responsible for what

basal glucose uptake

which stage of glucose is this (1 or 2): glucose is trapped in the cell and modified so that it can be cleaved into phosphorylated 3 carbon units.

stage 1

how many molecules of ATP is needed for the 1st stage of glycolysis

2

how many molecules of atp are generated in stage 1 of glycolysis

none

which stage of glucose is this (1 or 2): oxidizes a 3 carbon unit, forms pyruvate

stage 2

how many molecules of atp are formed in stage 2 of glycolysis

2

what does glucose do to the number of carbons

cuts it in half, from 6 to 3

what enzyme is used to convert glucose to glucose 6 phosphate

hexokinase

when is the first molecule of atp used in glycolysis

in the conversion of glucose to glucose 6 phosphate

what happens during the conversion of glucose to glucose 6 phosphate

atp loses 1 phosphate, it is added to the 6th carbon.

what is special about the conversion of glucose to glucose 6 phosphate using hexokinase

it is an irreversible step, and also rate limiting

what enzyme is used for convert glucose 6 phosphate to fructose 6 phosphate

phosphoglucose isomerase

what happens during the conversion of glucose 6 phosphate to fructose 6 phosphate

we go from a 5 carbon ring to a 4 carbon ring.

what is special about glucose 6 phosphate and fructose 6 phosphate

they are isomers

during glycolysis, what enzyme is used to convert fructose 6 phosphate to fructose 1,6 bisphosphate

phosphofructokinase

where is the 2nd ATP required in glycolysis

the conversion of fructose 6 phosphate to fructose 1,6 biphosphate

what happens during the conversion of fructose 6 phosphate to fructose 1,6 biphosphate

atp loses 1 phosphate group. that phosphate group is added to the molecule onto carbon 1

what is special about the conversion of fructose 6 phosphate to fructose 1,6 biphosphate

it is an irreversible reaction, and the first one specific to glycolysis

during glycolysis, what enzyme converts fructose 1,6 bisphosphate to glyceraldehyde 3 phosphate or dihydroxyacetone phosphate

aldolase

what enzyme converts glyceraldehyde 3 phosphate to dihydroxyacetone phosphate

triose phosphate isomerase

what happens during the conversion of fructose 1,6 biphosphate to glyceraldehyde 3 phosphate or dihydrosyacetone phosphate

the bond between the 3rd carbon and 4th carbon is broken. The bond between the oxygen and the 1st carbon is hydrolyzed.

Dihydroxyacetone phosphate can move onto stage 2 of glycolysis

false

what are kinases

enzymes that catalyze the transfer of a phosphoryl group from ATP to an acceptor

why is glucose trapped in the cell during conversion from glucose to glucose 6 phosphate

glucose 6 phosphate is negatively charged and is not a substrate for glucose transporters

what does hexokinase do during the conversion of glucose to glucose 6 phosphate

it facilitates the metabolism of glucose into 3 carbon molecules with high phosphoryl transfer potential

what is the first irreversible reaction of glycolysis

conversion of glucose to glucose 6 phosphate

what are the 2 purposes of ATP when taken in during the conversion of glucose to glucose 6 phosphate during glycolysis

drive the reaction and provide a phosphate group

what structure does glucose 6 phosphate have

aldose

what structure does fructose 6 phosphate have

ketose

what role does ATP play during the conversion of fructose 6 phosphate to fructose 1,6 biphosphate

drive reaction, and provide phosphate group

what does it mean to be an allosteric enzyme

the enzyme doesn’t bind to the active site, it binds somewhere else

what type of enzyme is phophofructokinase

allosteric enzyme

phosphofructokinase sets the pace of glycolysis. what does this mean

if you control the enzyme, you control glycolysis

what broken down reaction (with the enzyme) is occurring during the conversion of glucose 6 phosphate to fructose 6 phosphate

the enzyme must open the glucose 6 phosphate ring, catalyze the isomerization, and form the fructose 6 phosphate ring

what structure does glucose 6 phosphate have

aldose structure

what structure does fructose 6 phosphate have

ketose structure

what type of enzyme is phosphofructokinase

an allosteric enzyme

what is the first irreversible reaction that is committed to glycolysis

fructose 6 phosphate to fructose 1,6 biphosphate

what reaction completes stage 1 of glycolysis

fructose 1,6 biphosphate to dihydroxyacetone or glyceraldehyde 3 phosphate

what bond is cut during the conversion of fructose 1,6 biphosphate to dihydroxyacetone or glyceraldehyde 3 phosphate

the bond between carbon 3 and 4

which product from the conversion of fructose 1,6 biphosphate can be converted to pyruvate

glyceraldehyde 3 phosphate

can dihydroxyacetone phsophate be converted to glyceraldehyde 3 phosphate

yes, using triose phosphate isomerase

what is notable about triose phosphate isomerase

it is a kinetically perfect enzyme

what undesired side reaction does triose phosphate isomerase suppress

the conversion of enediol to methyl glyoxal, it’s done by losing inorganic phosphate.

what molecule does stage 2 of glycolysis start with

glyceraldehyde 3 phosphate

glyceraldehyde 3 phosphate is converted to 1,3 bisphosphoglycerate using what enzyme

glyceraldehyde 3 phosphate dehydrogenase

what other molecules are taken in during the conversion of glyceraldehyde 3 phosphate to 1,3 bisphosphoglycerate

Pi and NAD+

during glycolysis, what occurs during the conversion of glyceraldehyde 3 phosphate to 1,3 bisphosphoglycerate

NAD+ takes the hydrogen from the carbonyl carbon, phosphate is added in place of it.

what enzyme is used to convert 1,3 bisphosphoglycerate to 3 phosphoglycerate

phosphoglycerate kinase

what happens during the conversion of 1,3 bisphosphoglycerate to 3 phosphoglycerate

we take out a phosphate group to produce ATP

what enzyme is used to convert 3 phosphoglycerate to 2 phosphoglycerate

phosphoglycerate mutase

what happens during the conversion of 3 phosphoglycerate to 2 phosphoglycerate

mutase grabs the phosphate group from the 3rd carbon and puts it on the 2nd carbon

what enzyme is used to convert 2 phosphoglycerate to phosphoenolpyruvate

enolase

what happens during the conversion of 2 phosphoglycerate to phosphoenolpyruvate

h2o is removed

what enzyme is used to convert phosphoenolpyruvate to pyruvate

pyruvate kinase

during glycolysis what is taken in during the conversion of 1,3 bisphosphoglycerate to 3 phosphoglycerate

adp, to produce atp

what is the first step for ATP generation during glycolysis

the conversion of 1,3 bisphosphoglycerate to 3 phosphoglycerate using phosphoglycerate kinase

what happens during the conversion of 1,3 bisphosphoglycerate to 3 phosphoglycerate

adp removes the phosphate group from carbon 1 and makes atp

what is notable about stage 2 of glycolysis

it happens twice so you multiply all products by 2

what happens during the conversion of 2 phosphoglycerate to phosphoenolpyruvate

H2O is removed. H from the central carbon and OH from carbon 3.

what happens during the conversion of 3 phsophoglycerate to 2 phosphoglycerate

the enzyme (mutase) grabs the phosphate group and moves it from the 3rd carbon to the 2nd carbon

what happens during the conversion of phosphoenolpyruvate to pyruvate

adp is taken in. phosphate group is removed from carbon 2 and this generates atp

what is the 2nd step of glycolysis that produces atp

phosphoenolpyruvate to pyruvate

how many TOTAL nadh are produced from glycolysis

2

how many TOTAL atp are produced from glycolysis

4

1,3 bisphosphoglycerate has what phosphoryl-transfer potential

high potential

what is the NET production of ATP

2

does 1,3 biphosphoglycerate have a high or low phosphoryl transfer potential

high

what reaction in stage 2 of glycolysis is a sum of 2 processes

glyceraldehyde 3 phosphate to 1,3 bisphosphoglycerate

describe the thioester intermediate

very unstable, can be easily hydrolyzed by water

since 1,3 biphosphoglycerate has a greater phosphoryl transfer potential than ATP, what can it do

power the synthesis of ATP

atp is formed by substrate level phosphorylation, what does this mean

it is formed by the molecule 1,3 bisphosphoglycerate, which is a substrate of the enzyme phosphoglycerate kinase

why does phosphoenolpyruvate have a high phosphoryl transfer potential

the phosphoryl group traps the molecules in its unstable enol form which is high in energy

is the conversion from phosphoenolpyruvate to pyruvate, using pyruvate kinase, reversible or irreversible

irreversible

is the conversion of 3 phosphoglycerate to 2 phosphoglycerate, using phosphoglycerate mutase, reversible or irreversible

reversible

what reaction does this describe: glucose + 2Pi + 2 ADP + 2 NAD+ → 2 pyruvate + 2ATP + 2NADH + 2H+ + 2H20

glycolysis

the energy released in glycolysis is -90 kJ. does this mean the reaction is spontaneous or does not occur

it is spontaneous