Bio 1112009

Transformación de energía a partir de glucosa

Aeróbico – requiere O2

Reacción catabólica, donde se libera energía en forma de ATP

Reacciones REDOX

Reacción general del rompimiento de glucosa:

C6H12O6 + 6O2 6CO2 + 6H2O + ATP

Figure 8-1 Biology: Life on Earth 8/e ©2008 Pearson Prentice Hall, Inc.

34 or 36ATP

in mitochondria–oxygen required

in cytosol–no oxygen required

glycolysis

glucose

fermentationpyruvate

2 ATP

cellular respiration

O2

if no O2 availableethanol + CO2

orlactic acid

CO2

H2O

Glycolysis Formation of acetyl coenzyme A

Citric acid cycle

Electron transport and chemiosmosis

Glucose

Pyruvate

2 ATP 2 ATP 2 ATP

Acetyl coenzyme A

Citric acid cycle

Electron transport and chemiosmosis

1 2 3 4

Figure 8-6 Biology: Life on Earth 8/e ©2008 Pearson Prentice Hall, Inc.

cristae

mitochondrion

innermembrane

outermembrane

intermembranespace

matrix

Glycolysis Formation of acetyl coenzyme A

Citric acid cycle

Electron transport and chemiosmosis

Glucose

Pyruvate

2 ATP 2 ATP 2 ATP

Glucólisis Ocurre en el citoplasma En ausencia de oxígeno La glucosa se rompe y se obtiene dos piruvatos Se produce dos ATP por cada molécula de glucosa

Glucose

Glucose-6-phosphate

Fructose-6-phosphate

ATP ATP

ADPADP

Hexokinase Phosphofructokinase

Phosphoglucoisomerase

(continued)

(see next slide)

Fructose-1,6-bisphosphate

Dihydroxyacetonephosphate

Glyceraldehyde-3-phosphate (G3P)

Isomerase

Aldolase

(see previous slide)

Energy capture phaseFour ATPs and two NADH produced per glucose

2 ATP

2 ADP

(G3P)

5 steps

P(G3P)

Pyruvate Pyruvate

NADH

NAD+

P

2 ATP

2 ADP

NADH

NAD+

Net yield per glucose:Two ATPs and two NADH

Glycolysis Formation of acetyl coenzyme A

Citric acid cycle

Electron transport and chemiosmosis

Glucose

Pyruvate

2 ATP 2 ATP 2 ATP

1. Piruvato pasa a la mitocondria2. Piruvato se rompe en CO2 y acetil –CoA (2

carbonos)3. Se genera un NADH por cada molécula de

piruvato4. Decarboxilación oxidativa

Pyruvate

Acetyl Coenzyme A

Carbon dioxide

NADH

NAD+

Coenzyme A

Glycolysis Formation of acetyl coenzyme A

Citric acid cycle

Electron transport and chemiosmosis

Glucose

Pyruvate

2 ATP 2 ATP 2 ATP

1. Acetil entra al ciclo de Krebs

2. Se produce CO2

3. Se reducen las coenzimas NADH y FADH2

4. Se obtiene un ATP

Acetyl coenzyme A Coenzyme A

Citrate

NAD+NAD+

NADH

NADH

NADH

NAD+

CO2

ATP

GDPGTP

FADH2

FAD

H2O

ADP 4-carbon compound

CO2

Oxaloacetate

5-carbon compound

CITRIC ACID CYCLE

Coenzyme A

Oxaloacetate

Citrate Isocitrate

α-ketoglutarate

Glucose Fatty acids

Citrate synthase

Acetyl coenzyme AIsocitratedehydrogenase

α-ketoglutaratedehydrogenase

NADH

NADH

H2O H2OCO2

CO2

NAD+

NAD+

CITRIC ACID CYCLEPart 1

Coenzyme A

(see next slide) (see next slide)

Fumarate Succinate

Succinylcoenzyme AMalate

Coenzyme A

FADH2

FAD

Succinyl CoAsynthetase

Succinatedehydrogenase

(see previous slide) (see previous slide)

GTP

ADP GDP

ATPFumarase

Malatedehydrogenase

NADHNAD+

H2O

CITRIC ACID CYCLEPart 2

Glycolysis Formation of acetyl coenzyme A

Citric acid cycle

Electron transport and chemiosmosis

Glucose

Pyruvate

2 ATP 2 ATP 32 ATP

Reacciones de oxi-reducción, se transfieren electrones hasta que O2 acepta electrones e hidrógenos

Se produce H2O Ocurre en la membrana interna de la

mitocondria Se produce la mayor cantidad de ATPs

Figure 8-8 Biology: Life on Earth 8/e ©2008 Pearson Prentice Hall, Inc.

ATP

NAD

ADP+Pi

NADH FADH2

FAD

H2O2H+2e–1/2O2

intermembranespace

innermembrane

matrix

Oxygen is requiredto accept energy-depleted electrons.

H+ channel is coupled toATPsynthesizing enzyme.

Flow of H+ downconcentration gradientpowers ATP synthesis.

High H+ concentration isgenerated by active transport.

High-energy electron carriersfrom acetyl CoA formation, Krebscycle, and glycolysis feed into the ETC.

Energy fromhigh-energy electronspowers activetransport of H+ by ETC.

Cytosol

Intermembranespace

Outer mitochondrial membrane

Inner mitochondrial membrane

Matrix of mitochondrion

NADHNAD+

FADH2

FAD 2 H+

H2O1/2 O2

Complex I:NADH-ubiquinoneoxidoreductase

Complex II:Succinate-ubiquinonereductase

Complex III:Ubiquinone-cytochrome coxidoreductase

Complex IV:Cytochrome coxidase

Cytosol

Intermembranespace

Outer mitochondrial membrane

Inner mitochondrial membrane

Matrix of mitochondrion

Complex I Complex II

Complex III

Complex IV

Complex V:ATP synthase

(a)

Glycolysis

Glucose

Pyruvate

2 ATP

2 ATP

NADH

Acetyl coenzyme A

Citric acid cycle

Electron transport and chemiosmosis

2 4 – 6 ATP

NADH2 6 ATP

NADH6 18 ATP

FADH22 4 ATP

32 - 34 ATP

Total ATP fromoxidative phosphorylation

Substrate-levelphosphorylation

Oxidativephosphorylation

PROTEINS CARBOHYDRATES FATS

Aminoacids

Glycerol Fattyacids

Glucose

G3P

Pyruvate

Glycolysis

CO2

AcetylCoenzymeA

Citricacidcycle

Electrontransportandchemiosmosis

NH3 H2O CO2

Endproducts:

Fermentación láctica

En ausencia de oxígeno Célula muscular Se produce ácido

láctico

Dos ATP

Fermentación alcólica

En ausencia de oxígeno Célula de levadura Se produce alcohol

etílico y CO2 Dos ATP

Glucosa se fermenta Vino se prepara con levadura, azucar de las uvas

y se produce alcohol. El pan se elabora con levaduras, harina y azucar. Se obtiene Co2 que hace que la masa se expanda.

Figure E8-2 Biology: Life on Earth 8/e ©2008 Pearson Prentice Hall, Inc.