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Transition of GlycolysisGlycolysis to KrebsKrebs CycleCycle:1) Pyruvates enter mitochondria2) Pyruvates converts to Acetyl CoA
via. transport proteins
Transition from GlycolysisGlycolysis to Krebs Krebs cyclecycle:->Acetyl CoA
Transition from GlycolysisGlycolysis to Krebs Krebs cyclecycle:->Acetyl CoA
Transition from GlycolysisGlycolysis to Krebs Krebs cyclecycle:->Acetyl CoA
0xidized
Transition from GlycolysisGlycolysis to Krebs Krebs cyclecycle:->Acetyl CoA
Transition from GlycolysisGlycolysis to Krebs Krebs cyclecycle:->Acetyl CoA
X 2X 2
As a result of the transition to KrebsKrebs CycleCycle :22 Pyruvate Pyruvate --> 2 acetyl CoA (therefore Kreb’s will run (therefore Kreb’s will run
TWOTWO turnsturns of the Krebs of the Krebs cycle for cycle for eacheach originaloriginal glucose molecule!!!)glucose molecule!!!)22 NADH NADH & 2 CO2
The Krebs CycleKrebs Cycle:
Occurs in the matrix of the mitochondria.
The Krebs CycleKrebs Cycle:
Occurs in the matrix of the mitochondria.8 stepsremember: PyruvatesPyruvates (from glycolysis) have been converted to AcetylAcetyl CoACoA, THIS will now be metabolized.
1)1)Acetyl CoAAcetyl CoA joins to the 4 carbon
compound
OxaloacetateOxaloacetate= c-c-c-= c-c-c-c-c-cc-c-c
S-CoA removed = now now Citrate Citrate
2) H2O given off & added ISOMER
3) CO CO22 is given off c-c-c-c-c oxidized
-->
NAD+ --> NADH + NADH + HH++ -->
KetoglutarateKetoglutarate
4)COCO22 is given off
c-c-c-c oxidized via.
NAD+ NAD+ -->--> NADHNADH
CoA CoA attaches --attaches --> > Succinyl Succinyl CoACoA
5) CoA given off
phosphate group given to ADP via. GTP
ADP --> ATP Succinate
6) 2 Hydrogens reduce FAD
FAD --> FADH2
Fumarate
7) Addition of H2O
-->Malate
8) NAD+ --> NADH
reducedOxalocetOxalocetateate
ProductsProducts =
3 NADH X2
1 FADH2 X2
2 CO2 X2
1 ATP X22ATP
2FADH2
6NADH
Electron Transport Electron Transport ChainChain:
Occurs in the cristae (folds) of inner membrane of mitochondria. end result = 34 ATPs34 ATPs
Electron Transport Electron Transport ChainChain:
How does it work… 1)HIGH ENERGY electrons “shuttle” from one “acceptor molecule” to another.
This “collection” of proteins that are
structurally linked
Electron Transport Electron Transport ChainChain:
How does it work… 1)HIGH ENERGY electrons “shuttle” from one acceptor molecule to another. •At each “stop”, e-’s are transferred between molecules- they are reduced and then oxidized
Electron Transport Electron Transport ChainChain:
How does it work… •The last molecule in the chain passes e-’s to OxygenOxygen--> VERY electronegative.
•Oxygen then “picks up”
2 H+ --> H2O.
Electron Transport Electron Transport ChainChain:
•these electron transferers -> fuel the pumping of H+ from the mitochondrial matrix to the inner membrane space
Electron Transport Electron Transport ChainChain:
H+
H+
H+
H+H+
H+
H+
H+
H+H+
H+
H+
H+
H+
H+
H+ H+
H+
H+H+
ATP synthase= ENZYMEInner membrane space
Matrix
ATP synthase= ENZYME
It’s a “mill”
INTERMEMBRANE SPACE
H+ H+
H+H+
H+
H+
H+
H+
ATP
MITOCHONDRAL MATRIX
ADP+
A rotor within the membrane spins as shown when H+ flows past it down the H+ gradient.
A stator anchored in the membrane holds the knob stationary.
A rod (or “stalk”) extending into the knob also spins, activating catalytic sites in the knob.
Three catalytic sites in the stationary knob join inorganic phosphate to ADP to make ATP.
P
EnergyEnergy, , b/c of b/c of the the HH++ gradient.gradient.. That is . That is chemiosmochemiosmotic to tic to the the educated educated student!!student!!,, powers powers thethe
“mill”.“mill”.
Inner membrane space
electrons are “grabbed” and H+’s are “squirted” into the inner mitochondrial space.
http://www2.nl.edu/jste/electron_transport_system.htm
The electron transport chain thus establishes a proton gradient across the inner mitochondrial
membrane.
Chemiosmosis:Chemiosmosis:
•potential energy stored in the gradient is
released and captured to form ATP from ADP and
phosphate via the enzyme: ATP Synthase.
34 ATP’s 34 ATP’s result!!result!!
Every 1 NADH -> Every 1 NADH -> 3ATP3ATP
Every 1 FADHEvery 1 FADH22-> -> 2ATP2ATP
Lets practice…Lets practice…
Are the pieces Are the pieces coming coming
together?together?