Glycolysis Flashcards
(15 cards)
What is the first step of Glycolysis?
Hexokinase uses 1 ATP To Add Phosphate To Glucose, Forms Glucose-6-Phosphate
Why Is A Phosphate Added To Glucose?
To trap Glucose In The Cell + Destabilize It For Further Breakdown
What Is The Second Step Of Glycolysis?
Phosphoglucoseisomerase converts G6P To Fructose-6-Phosphate
Why is G-6-P Converted into F-6-P?
- To Prepare Sugar For Cleavage
- Cleavage Requires A Ketose (F-6-P), Not An
Aldose (G-6-P)
What is The Third Step of Glycolysis?
Phosphofructokinase Uses 1 ATP To Convert F6P To Fructose 1,6 Biphosphate
Why is PFK A Key Regulator Of Glycolysis?
It Catalyzes An Irreversible Reaction That “Locks” F 1,6 BP Into Glycolysis
What happens after F 1,6 BP is produced?
- Aldolase (Class I in Animals, Class II In
Bacteria) Splits Fructose 1,6 Biphosphate Into
x2 3 Carbon Sugars: - Dihydroxyacetone Phosphate (DHAP)
- Glyceraldehyde-3-Phosphate (G3P)
- (Reversible Reaction Near Equilibrium)
What Happens After F 1,6 BP Is Split Into x2 3 Carbon Molecules?
Triose Phosphate Isomerase Converts Dihydroxyacetone Phosphate (DHAP) Into A Second Glyceraldehyde 3 Phosphate (G3P)
Reason:
Only G3P Is Able To Continue Down The Pathway
What Happens After The Second G3P Is Made?
- G3P Dehydrogenase Oxidizes G3P Molecules
- Aldehyde Group Of G3P Converted To
Carboxyl Group (NAD Reduced) - Active-Site Cysteine Forms Thioester With
Oxidized Substrate - Pi Attacks Thioester, Creating High-Energy Acyl- Phosphate Bond
Product: 1,3-Bisphosphoglycerate
What Happens After 1,3-Biphosphoglycerate Is Made?
- Phosphoglycerate Kinase Transfers
Phosphate on C1 of 1,3-BPG To ADP - This Produces ATP (x2 Per Glucose) And x2 3
Phosphoglycerate Molecules
Reversible If Needed (Gluconeogenesis)
What Happens After 3-Phosphoglycerate Is Produced?
Phosphoglycerate Mutase Moves Phosphate Group in 3-Phosphoglycerate From Carbon 3 To Carbon 2, forming 2-Phosphoglycerate
What Happens After 2-Phosphoglycerate Is Produced?
- Enolase Carries Out Dehydration Reaction
- Water Molecule Removed From 2-Phosphoglycerate
- Phosphoenolpyruvate Formed
What Happens After Phosphoenolpyruvate Is Produced?
Pyruvate Kinase Transfers Phosphate From Phosphoenolpyruvate (PEP) to ADP, Forming:
- ATP
- Pyruvate
Happens Twice Per Glucose Molecule, you get:
- 2 ATP
- 2 Pyruvate Molecules
What Are The Net products of Glycolysis?
- 2 ATP
- 2 NADH
- 2 Pyruvate
What Is The Purpose Of Glycolysis?
To Breakdown Glucose into 2 molecules Of Pyruvate (3 Carbons Each)
To Extract Energy From Glucose via ATP + NADH
Lower Blood Glucose Levels
