You design lecturea. Discuss the research that “proved” Rotational
Catalysis
b. Review Metabolism and Electron Transport Chain from previous two classes
c. Explain how Glycolysis is like eating Pizza!
d. Talk about Fermentation as an option in some cells
e. Discuss Krebs Cycle and the path inside the mitochondria like the events in the Biovisions movie
Hiroyasu Itoh –designed this approach (Nature 2004)
“Reporter enzyme” emits light when detects new ATP
• Analyze the data. Given that the gray bars represent the basal/background level of ATP in the experiment, explain what you believe would be (i) predictions v. (ii) observations
Proteins
Carbohydrates
Aminoacids
Sugars
Fats
Glycerol Fattyacids
Glycolysis
Glucose
Glyceraldehyde-3-
Pyruvate
P
NH3
Acetyl CoA
Citricacidcycle
Oxidativephosphorylation
Enzyme 1 Enzyme 2 Enzyme 3
Start ofpathway X
Presence of product inhibits enzyme 1
Homeostasis: What is negative feedback?
Inter-mediate
Inter-mediate Product
Glucose
GlycolysisFructose-6-phosphate
Phosphofructokinase
Fructose-1,6-bisphosphateInhibits
AMP
Stimulates
Inhibits
Pyruvate
CitrateAcetyl CoA
Citricacidcycle
Oxidativephosphorylation
ATP
+
––
The electron transport chain occurs in the inner membrane of the mitochondrion (in regions called “cristae”)
ELECTRON TRANSPORT CHAIN
H+
NAD+ FAD
Complex I Complex II Complex III Complex IV
Cyt c
FADH2
NADH
Inner membrane
O2
Q
H+
H+
H+H+
H+
H+
H+H+
H+
H+
H+H+
H+
H+H+
H+H+
H+
H+
H+
H+
H+
H+
H2O
H+
H+
H+H+
H+
H+
H+
H+
H+
H+
Q
ATP
ELECTRON TRANSPORT AND OXIDATIVE PHOSPHORYLATION
FERMENTATION
Cellular respiration
KREBS CYCLE
Glucose Pyruvate
GLYCOLYSIS
If electron acceptor (such as oxygen)
is present
If electron acceptor (such as oxygen) is
NOT present
ADP
GLYCOLYSIS
All 10 reactions of glycolysis occur in cytosol
Glucose-6-phosphate
What goes in:
What comes out:
2
Fructose-6-phosphate
Fructose-1,6-bisphosphate
ATP
Glycolysis begins with an energy-investment phase of 2 ATP
ADP
ATP
1 3 4 5
Glucose
Meet PIP (Phosphorylate-Isomerize-Phosphorylate)
• Is that really the best way to hold on to your pizza?
ADP
GLYCOLYSIS
Glucose-6-phosphate
What goes in:
What comes out:
2
Fructose-6-phosphate
Fructose-1,6-bisphosphate
ATP
Energy-investment phase
ADP
ATP
1 3 4 5
Glucose
Hexokinase (capture)
PFK*phosphoglucoisomerase
[ATP] high
P PI
??????
ATP at regulatory site
Fructose- 1,6-bisphosphate at active site
ATP at active site
PFK is highly regulated
ADP
GLYCOLYSIS
Glucose-6-phosphate
What goes in:
What comes out:
2
Fructose-6-phosphate
Fructose-1,6-bisphosphate
ATP
Energy-investment phase
ADP
ATP
1 3 4 5
Glucose
hexokinase PFK*phosphoglucoisomerase
aldolase
isomerase
DHAP
[ATP] high
P PI
G-3-PG-3-P
inhibitsGlyceraldehyde-3-phosphate (G3P)-dehydrogenase
[ADP] [AMP]
stimulates
ADP
GLYCOLYSIS
All 10 reactions of glycolysis occur in cytosol
Glucose-6-phosphate
What goes in:
What comes out:
2
Fructose-6-phosphate
Fructose-1,6-bisphosphate
ATP
Glycolysis begins with an energy-investment phase of 2 ATP
ADP
ATP
1 3 4 5
Glucose
G-3-P
Glyceraldehyde-3-phosphate(G3P)-dehydrogenase
G-3-P
During the energy payoff phase, 4 ATP are produced for a net gain of 2 ATP
7 6 8 9 10
22 NAD+
2 NADH
2 ADP
2 ATP
Pyruvate
2 ATP
2 ADP2
22 2
The “2” indicates that glucose has been split into two 3-carbon sugars
Phosphoglycero(PG)-kinase
3-PGA1,3-BisPGA
G-3-P-dehydrogenase
2 G-3-P
Energy payoff phase
pyruvate kinase
SUMMARY OF GLUCOSE OXIDATION
Mitochondrion
Glucose
2 NADH
2 Pyruvate
Cytoplasm
2 ATP
Where do we go next?
SUMMARY OF GLUCOSE OXIDATION
Mitochondrion
Glucose
2 NADH
2 Pyruvate
Cytoplasm
2 ATP
If you have O2, enter the Matrix
SUMMARY OF GLUCOSE OXIDATION
Mitochondrion
2 Acetyl CoA Glucose
2 NADH
2 CO2
2 Pyruvate
Cytoplasm
2 ATP
2 NADH
Where do we go next?
SUMMARY OF GLUCOSE OXIDATION
Mitochondrion
2 Acetyl CoA Glucose
2 NADH 6 NADH2 FADH2
2 ATP2 CO2
4 CO2 2 Pyruvate KREBS CYCLE
Cytoplasm
2 ATP
2 NADH