Glycolysis Flashcards
What are the two stages of Glycolysis?
Energy-investing reactions (consume ATP)
Energy-harvesting reactions (produce ATP)
Which stage of Glycolysis produces ATP?
stage 2- energy-harvesting raactions
what is the purpose of Glycolysis?
Convert 6-C Glucose –> two 3-C Pyruvate
What are the two steps in Parts 1 (reactions 1-5)
Glucose phosphorylated (add P) at C1 and C6
Glucose 6C ring is cleaved into 2 3C glyceraldheyde-3-phosphate
What are the four steps in Parts 1 (reactions 6-10)
Convert metabolic energy of GP3 –> ATP
4 new ATPS produced
2 ATPSs used in part 1
Net yeild = 2 ATPS
What is the first step of glycolysis? (enzyme and reaction)
Hexokianse
D-Glucose + ATP –> Glucose 6-phosphate + ADP
What is the second step of glycolysis? (enzyme and reaction)
Hexose Isomerease/ Phosphohexose Isomerase
Glucose-6-P <–> Fructose-6-P
What occurs in the 2nd step of glycolysis? (words)
Ring rearranges into 5-mememebred fructose ring 9moves carboynal group)
What is the third step of glycolysis? (enzyme and reaction)
Phosphofructokinase
F-6-P –> F1.6-bisphosphate + ADP
What occurs in the 3rd step of glycolysis? (words)
Adds second phosphate to ring
What steps of glycolysis are irreversible and why?
Steps 1-3, 5-6 and 10, due to negative Gibbs free energy (non-spontaneous).
What is the fourth step of glycolysis? (enzyme and reaction)
Aldolase A
F1,6-bisphosphate <–> dihydrochalcone phosphate + glyceraldehyde-3-p
What occurs in the 4th stage (words)?
Ring is opened and cleaved into two 3 carbon sugar phosphates
What are the two rings called that Aldolase A produces?
1 = dihydroxy-acetone phosphate
2= glyceraldehyde 3-phosopahte
What is the fifth step of glycolysis? (enzyme and reaction)
isomerase
DHAP –> G3P
What is the sixth step of of glycolysis? (enzyme and reaction)
(first energy harvesting)
Glyceraldehyde 3-phosphate dehydrogenase
G3P + Pi + NAD+ <–> 1,3 Bisphosphoglyceate + NADH2
What occurs in the 6th stage (words)?
Converts G3P into 1,3-PGA as well as NAD –> NADH2
Transfers free P to C1
What is the seventh step of of glycolysis? (enzyme and reaction)
3-Phosphoglycerate Kinase (subsrate level of phosphorylation)
1,3BPG + ADP <–> 3PG + ATP
What occurs in the 7th stage (words)?
Forms high energy P bonds where not previols
What is the eighth step of of glycolysis? (enzyme and reaction)
Phosphogoglycerate Mutase
3PG <–> 2PG
What occurs in the 8th stage (words)?
P moves from C2 to C3
What is the ninth step of of glycolysis? (enzyme and reaction)
Enolase
2PG <–> Phosphoenolyruvate (PEP) + H2O
What occurs in the 9th stage (words)?
Removes water from 3PG to make PEP
What is the tenth step of of glycolysis? (enzyme and reaction)
Pyruvate kinase
PEP + ADP <–> Pyruvate + ATP
What occurs in the 10th stage (words)?
Transfers phosphate from PEP to ADP
What is Substrate-level phosphorylation?
enzyme catalysed transfer of phosphate from donor molecules to ADP
for every mole of glucose that enters glycolosys, how many moles of pyruvate are produced?
2 Moles