Download LB145-lecture20

design
lecture
a. Discuss theYou
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
Masasuke Yoshida “Ummm… check this out.”
Masasuke Yoshida “Ummm… check this out.”
Masasuke Yoshida “Ummm… check this out.”
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
Figure 1 Itoh et al, Nature 2004
9
You design lecture
Proteins
Carbohydrates
Amino
acids
Sugars
Glycolysis
Glucose
Glyceraldehyde-3- P
NH3
Pyruvate
Acetyl CoA
Citric
acid
cycle
Oxidative
phosphorylation
Fats
Glycerol
Fatty
acids
Homeostasis: What is negative feedback?
Start of
pathway
X
Enzyme 1
Intermediate
Enzyme 2
Presence of product inhibits enzyme 1
Intermediate
Enzyme 3
Product
Glucose
AMP
Glycolysis
Fructose-6-phosphate
–
Stimulates
+
Phosphofructokinase
–
Fructose-1,6-bisphosphate
Inhibits
Inhibits
Pyruvate
ATP
Citrate
Acetyl CoA
Citric
acid
cycle
Oxidative
phosphorylation
The electron transport chain
occurs in the inner membrane of
the mitochondrion (in regions
called “cristae”)
ELECTRON TRANSPORT CHAIN
H+ H+
H+ H+ H+
H+ + H+
H
H+
H+
H+
+
+
+
H+H H H
H+
H+
H+
Q
H+
H+
H+
H+
H+
H+
H+
H+
H+
H+ H+
H+
H+
Cyt c
Q
NADH
NAD+
H+
Complex I
Inner membrane
FADH2
FAD
Complex II
H+
H+
O2
H2O
Complex III
Complex IV
ATP
You design lecture
Cellular respiration
GLYCOLYSIS
Glucose
If electron acceptor
(such as oxygen)
is present
KREBS CYCLE
ELECTRON TRANSPORT AND
OXIDATIVE PHOSPHORYLATION
Pyruvate
If electron acceptor
(such as oxygen) is
NOT present
FERMENTATION
All 10 reactions
of glycolysis
occur in cytosol
GLYCOLYSIS
What
goes in: ATP
ATP
1
Glucose
What
comes out:
2
Glucose6-phosphate
ADP
3
Fructose6-phosphate
4
Fructose1,6-bisphosphate
ADP
Glycolysis begins with an energyinvestment phase of 2 ATP
5
PIP
• Think of the beginning of “Glyco-lysis”
as eating a pizza
Think Glucose = Pizza
The common ‘hexo-pyranose’ form of Pizza
Meet PIP
(Phosphorylate-Isomerize-Phosphorylate)
• Is that really the best way to hold on to your pizza?
Aldolase =
Fructose 1-6 Bisphosphate -> DHAP (ick) and G-3-P (tasty!)
Isomerase ->
DHAP (ick)
G-3-P (tasty!)
Isomerase ->
G-3-P (tasty!) G-3-P (tasty!)
Energy-investment phase
GLYCOLYSIS
What
goes in: ATP
ATP
P
I
1
Glucose
What
comes out:
P
2
Glucose6-phosphate
3
Fructose6-phosphate
ADP
Hexokinase
(capture)
4
Fructose1,6-bisphosphate
ADP
phosphoglucoisomerase
PFK*
??????
[ATP] high
5
PFK is highly regulated
ATP at
active site
Fructose- 1,6bisphosphate at
active site
ATP at
regulatory site
Energy-investment phase
GLYCOLYSIS
aldolase
What
goes in: ATP
P
I
1
Glucose
What
comes out:
DHAP
ATP
P
2
Glucose6-phosphate
3
Fructose6-phosphate
ADP
hexokinase
Fructose1,6-bisphosphate
ADP
phosphoglucoisomerase
PFK*
stimulates
5 isomerase
4
G-3-P
G-3-P
inhibits
Glyceraldehyde-3-phosphate (G3P)-dehydrogenase
[ATP] high
[ADP] [AMP]
Phosphoglycero(PG)-kinase
Glyceraldehyde-3-phosphate(G3P)-dehydrogenase
PIP
All 10 reactions
of glycolysis
occur in cytosol
GLYCOLYSIS
What
goes in: ATP
ATP
1
Glucose
What
comes out:
2
Glucose6-phosphate
ADP
3
Fructose6-phosphate
4
5
Fructose1,6-bisphosphate
ADP
G-3-P
G-3-P
Glyceraldehyde-3-phosphate(G3P)-dehydrogenase
Glycolysis begins with an energyinvestment phase of 2 ATP
Energy payoff phase
Phosphoglycero(PG)-kinase
The “2” indicates that glucose has
been split into two 3-carbon sugars
2 NAD+
2 ADP
2
6
2 G-3-P
2
2
7
1,3-BisPGA
8
2
9
2 ADP
2
10
Pyruvate
3-PGA
pyruvate
kinase
2 NADH
G-3-P-dehydrogenase
2 ATP
2 ATP
During the energy payoff phase, 4 ATP are produced for a
net gain of 2 ATP
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You design lecture
Where do we go next?
SUMMARY OF GLUCOSE OXIDATION
2 NADH
Glucose
2 Pyruvate
2 ATP
Cytoplasm
Mitochondrion
Pyruvate Dehydrogenase
Multienzyme Complex
If you have O2, enter the Matrix
SUMMARY OF GLUCOSE OXIDATION
2 NADH
Glucose
2 Pyruvate
2 ATP
Cytoplasm
Mitochondrion
Where do we go next?
SUMMARY OF GLUCOSE OXIDATION
2 NADH
Glucose
2 Pyruvate
2 ATP
Cytoplasm
2 NADH
2 Acetyl CoA
2 CO2
Mitochondrion
SUMMARY OF GLUCOSE OXIDATION
2 NADH
Glucose
2 Pyruvate
2 ATP
Cytoplasm
2 NADH
2 Acetyl CoA
2 CO2
Mitochondrion
6 NADH
2 FADH2
KREBS
CYCLE
2 ATP
4 CO2
Is this what the Citric Acid Cycle looks like?
Is this what the Citric Acid Cycle really looks like?
What about this?
Actually…
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