Biochem Test 3 Glycolysis Phase 2

how does the cell regulate glycolysis

by regulating:

• hexokinase

• phosphofructose kinase (PFK)

• pyruvate kinase

• lactate dehydrogenase → under anaerobic conditions

what turns glycolysis on or off

slowing down or speeding up the enzymes of the three reactions

how much ATP is used in phase 2

0 ATP

how much ATP is produced in phase 2

4 ATP

what is the total net yield of ATP in glycolysis

2 ATP

what are the 2 high energy intermidiates of phase 2 that make ATP and what do they do

• 1,3 bisphosphoglycerate

• phosphoenol pyruvate

• donate their phosphate group to ADP to make ATP

what enzyme is used to catalyze rxn 6 of glycolysis

glyceraldehyde-3-phosphate dehydrogenase

what molecule is altered during rxn 6 and what happens

a phosphate group is added to glyceraldehyde 3 phosphate

where does the phosphate group come from

an inorganic phosphate

what forms during rxn 6

glyceraldehyde 3 phosphate becomes 1,3 bisphosphoglycerate

does a redox rxn occur during rxn 6?

• NAD+ is reduced to NADH

• the aldehyde group on G3P gets oxidized to COOH

arsenate is similar to what molecule

inorganic phosphate

what happens when G3P binds to arsenate

no net ATP is made during glycolysis

what enzyme is used to catalyze rxn 7

phosphoglycerate kinase

what does phosphoglycerate kinase do

phosphoglycerate kinase transfers a phosphate group from 1,3 BPG tto ADP to make ATP

what type of phosphorylation occurs during rxn 7

substrate level phosphorylation since the phosphate group came from an organic sugar intermidiate

what cofactor is used during rxn 7

Mg 2+

what is produced during rxn 7

2 ATP

what enzyme catalyze rxn 8

phosphoglycerate mutase

what does phosphoglycerate mutase do

moves a phosphate group from C3 to C2 on 3 phosphoglycerate

why is it important for the phosphate group to be relocated on 3-phosphoglycerate

allows enolase to form PEP in rxn 9

what enzyme catalyzes rxn 9

enolase

what does enolase do

removes a molecule of H2O from 2-phosphoglycerate to convert it to phosphoenolpyruvate (PEP)

what is formed in rxn 9

PEP

what enzyme catalyzes rxn 10

pyruvate kinase

what does pyruvate kinase do

transfers a phosphate group from PEP to ADP to make ATP

what type of phosphorylation occurs in rxn 10

substrate level phosphorylation

what is the product of rxn 10

the 2 net ATP of glycolysis

what activates pyruvate kinase (2)

• high AMP → means low ATP/energy

• high fructose 1,6 bisphosphate

what inhibits pyruvate kinase (3)

• high ATP and Acetyl CoA → signals that theres enough energy

• high alanine → signals that theres enough pyruvate

what regulates liver pyruvate kinase

colvant modification

what does the presence of AMP in a cell indicate (2)

• low energy/ATP

• pyruvate kinase is activated

fate of NADH in aerobic conditions

NADH is oxidized in the ETC to power oxidative phosphorylation to make ATP

fate of NADH in anaerobic conditions (2)

• LDH (lactate dehydrogenase) take e- from NADH and gives it to pyruvate → pyruvate becomes lactate

• NADH is oxidized to NAD+

fate of pyruvate in aerobic conditions

• goes to the TCA cycle

fate of pyruvate in anaerobic conditions and what is it an example of

• pyruvate becomes lactate in mammals and ethanol in yeast

• example of fermentation

what is the name of the cycle that makes lactate

Cori cycle

what happens in the muscles during the Cori Cycle (2)

• pyruvate gets reduced to lactate by lactate dehydrogenase

• NADH gets oxidized to NAD+

once lactate is formed in the muscles where does it go

• lactate travels to the liver via bloodstream

what happens once lactate arrives at the liver (3)

• lactate dehydrogenase converts lactate back into pyruvate

• glucogensis occurs in the liver to turn pyruvate into glucose

• glucose leaves the liver and travels to the muscles via the bloodstream