Glycolysis and Krebs Cycle

1
Glycolysis and Krebs Cycle
2
Net Results of Glycolysis and Krebs Cycle

• Glycolysis
• IN Glucose 2 ATP
• OUT 2 Pyruvate 4 ATP 2 NADH
• 2 ATP in and 4 ATP out a net gain of 2 ATP
• Krebs Cycle (x2)
• IN Pyruvate
• OUT 1 ATP 4 NADH 1 FADH2 3 CO2
• Thus, 10 NADH 2 FADH2 go to the ETC to create
  more ATPs.

3
Types of Enzymes in Respiration

• Kinase adds a phosphate
• Dehydrogenase does REDOX reactions
• Isomerase converts between isomers
• Synthase creates big molecules from small ones
• Where is the control point in Glycolysis?

4
Coupled Reactions

• Endergonic reactions to occur more readily when
  coupled with an exergonic reaction
• The NET ?G must be negative
• Common exergonic reactions
• NADH ? NAD ?G -53 kcal/mol
• FADH2 ? FAD ?G -39 kcal/mol
• ATP ? ADP Pi ?G -7.3 kcal/mol

5
Example Problem
Fructose-6-Pi
ATP
ADP
Fructose-1,6-bisphosphate
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Example Problem

• A Fructose-6-Phosphate
• B ATP
• C Fructose-1,6-Bisphosphate
• D Less than 7.3 kCal/mol
• E Kinase

7
Reaction 1
Isocitrate
CO2
NAD
NADH
a - Ketoglutarate
8
Reaction 1
9
Reaction 2
Phosphoenolpyruvate
ADP
ATP
Pyruvate
10
Reaction 2
11
Reaction 3
Malate
NAD
NADH
Oxaloacetate
12
Reaction 3
13
Reaction 4
Glucose
ATP
ADP
Glucose-6-Phosphate
14
Reaction 4
15
Reaction 5
Pyruvate
CO2
NAD
NADH
Coenzyme A
Acetyl CoA
16
Reaction 5
17
Reaction 6
Succinate
FAD
FADH2
Fumarate
18
Reaction 6
19
Reaction 7
Glucose-6-Phosphate
Organic molecule is rearranged
Fructose-6-Phosphate
20
Reaction 7
21
Reaction 8
Glyceraldehyde-3-P
NAD
2 Pi
NADH
1,3-Bisphoglycerate
22
Reaction 8
23
Reaction 9
a-Ketoglutarate
NAD
CoA-SH
NADH
CO2
Succinyl CoA
24
Reaction 9