LESSON 10 : GLYCOLYSIS

Question 1

2 phases of Glycolysis

Answer 1

• Energy-investment phase (5 steps)
• Pay-off phase (5 steps)

Question 2

Glycolysis occurs in the

Answer 2

Cytosol

Question 3

Step 1: Phosphorylation of glucose

Answer 3

• A phosphate group is added to glucose using the enzyme Hexokinase
• 1 ATP is used
• ( glucose 6-phosphate (G6P) and ADP is produced )

Question 4

Step 2: Isomerization of Glucose-6-Phosphate

Answer 4

• The Enzyme phosphoglucose isomerase, Isomerizes G6P to fructose-6- phosphate(F6P)
• Isomer : Same molecular formula different arrangement

Question 5

Step 3: Phosphorylation of F6P

Answer 5

• Fructose-6-Phosphate gains a phosphate group with the help of phosphofructokinase • 1 ATP is used
• fructose-1,6-bisphosphate (FBP) and ADP is produced

Question 6

Step 4: Splitting of fructose-1,6-bisphosphate

Answer 6

• FBP is split into two molecules, glyceraldehyde-3-phosphate (G3P) & dihydroxyacetone phosphate (DHAP), with the help of the enzyme, aldolase

Question 7

Step 5: Conversion of DHAP to G3P

Answer 7

• dihydroxyacetone phosphate is converted to glyceraldehyde-3-phosphate with the help of the enzyme Triose Phosphate Isomerase
• Final step of the investment phase

Question 8

What are used and and produced in Investment Phase

Answer 8

Glucose -> 2 molecules of G3P
2 NADH is produced
2 molecules of ATP was used

Question 9

Step 6: Oxidation of G3P

Answer 9

• G3P is oxidized by NAD+ facilitated by
glyceraldehyde-3-phosphate dehydrogenase • 1,3-bisphosphoglycerate (1,3-BPG) and NADH is produced
• Reaction is exergonic

Question 10

Step 7: Substrate-level phosphorylation of 1,3- BPG

Answer 10

• Phosphoglycerate kinase takes one Phosphate group from 1,3-BPG and gives it to ADP
• 3-phosphoglycerate (3PG) and ATP is produced

Question 11

a form of ATP synthesizing reaction where a phosphate from a high energy compound is transferred to ADP to make ATP
ADP ATP

Answer 11

Substrate Level Phosphorylation

Question 12

Step 8: Movement of phosphate group of 3PG

Answer 12

• phosphoglycerate mutase moves the phosphate group from carbon 3 to carbon 2 to make 2-phosphoglycerate(2PG)
• Mutase: catalyzes migration of functional group within the substrate

Question 13

Step 9: Conversion of 2PG to

Answer 13

• Phosphoenolpyruvate
• Enolase rearanges the molecules of 2PG to create Phosphoenolpyruvate (PEP)
• Water is released as a by-product

Question 14

Step 10: Conversion of PEP to pyruvate

Answer 14

• PEP readily gives its phosphate group to ATP with the help of pyruvate kinase
• Pyruvate and ATP is produced
• Final step of Glycolysis

Question 15

Step 10: Conversion of PEP to pyruvate

Answer 15

• PEP readily gives its phosphate group to ATP with the help of pyruvate kinase
• Pyruvate and ATP is produced
• Final step of Glycolysis

Question 16

Investment Phase summarization

Answer 16

• 2 molecules of G3- -> 2 molecules of Pyruvate
• Products: 1.4 molecules of ATP 2.2 molecules of NADH

Question 17

The chemical reaction that turns Pyruvate into Acetyl-CoA is called

Answer 17

Oxidative Decarboxylation

Question 18

Aerobic respiration product check!

Answer 18

Glycolysis
2 molecules of ATP
2 molecules of NADH

Pyruvate oxidation
2 molecules of NADH

Total: 2 ATP 4 NADH