Glycolysis Krebs Cycle Transition of Glycolysis to Krebs Cycle : 1) Pyruvates enter mitochondria 2) Pyruvates converts to Acetyl CoA via. transport.

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



0xidized



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


How does it work… 1)HIGH ENERGY electrons “shuttle” from one “acceptor molecule” to another.

This “collection” of proteins that are

structurally linked


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


How does it work… •The last molecule in the chain passes e-’s to OxygenOxygen--> VERY electronegative.

•Oxygen then “picks up”

2 H+ --> H2O.


•these electron transferers -> fuel the pumping of H+ from the mitochondrial matrix to the inner membrane space


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?

Glycolysis Krebs Cycle Transition of Glycolysis to Krebs Cycle : 1) Pyruvates enter mitochondria 2) Pyruvates converts to Acetyl CoA via. transport.

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