Ch 6

Cellular Respiration

Energy for lifeECOSYSTEM

Photosynthesisin chloroplasts

Glucose

Cellular respirationin mitochondria

H2O

CO2

O2

(for cellular work)

ATP

Heat energy

Breathing vs Cellular Respiration

• Breathing- gas exchange• Cellular respiration- aerobic harvesting of

energy from food molecules by cells

Cellular Respiration

• Stores energy in ATP

C6H12O6 + 6 O2

Glucose Oxygen

6 CO2

Carbondioxide

+ 6 H2O

Water

+ ATPs

Energy

Cell Respiration

Redox

• Oxidation- loss of e-• Reduction- addition of e-

Loss of hydrogen atoms(oxidation)

6 CO2 + 6 H2O + Energy

Gain of hydrogen atoms(reduction)

(ATP)C6H12O6 + 6 O2

Glucose Oxidation

• Dehydrogenase• NAD+

2 H+ + 2 e–

Oxidation

Dehydrogenase

ReductionNAD+ + 2 H NADH + H+

(carries2 electrons)

ETC• Electron Transport Chain

ATPNAD+

NADH

H+

H+2e–

2e–

Electron transport

chain

Controlledrelease ofenergy forsynthesis

of ATP

+

O2

H2O

12

Cell Respiration

Glycolysis

• Splits sugar• Breaks Glucose into 2

three C sugars• Yields 2 pyruvate

molecules –Net gain of +2 ATP

Glucose

NAD++ 2

2 ADP

NADH2

P2

2

ATP2+

H+

2 Pyruvate

Glycolysis

• Substrate-level phosphorylation– Transfer of P from substrate to ADP

• Energy banked in ATP and NADH

ADP

ATP

Enzyme

Product

Enzyme

P

P

PSubstrate

Formation of Acetyl CoA

Krebs Cycle

Oxidative Phosphorylation

OXIDATIVE PHOSPHORYLATION

Stopping the chain

ATP

H+

O2

H2O

12 H+

NAD+NADH

FADH2FAD

PADP +

Chemiosmosis

+ 2

Electron Transport Chain

H+

H+H+

H+

H+H+

ATPsynthase

DNP

H+

H+

H+

Rotenone Cyanide,carbon monoxide

Oligomycin

DNP

ATP yieldCytoplasm

Glucose

FADH2

Mitochondrion

Maximum per glucose:

OXIDATIVEPHOSPHORYLATION(Electron Transportand Chemiosmosis)

CITRIC ACIDCYCLE

Electron shuttleacross membrane

2NADH

2 NADH

2NADH

6 NADH 2

(or 2 FADH2)

2 AcetylCoA

GLYCOLYSIS2

Pyruvate

About38 ATP

about 34 ATP

by substrate-levelphosphorylation

by oxidative phosphorylation

2 ATP

by substrate-levelphosphorylation

2 ATP

FermentationGlucose

NADH

NAD+

2

2 2 ADP

P

ATP2

NADH

2

NAD+

2

2 ADP

P

ATP2

2 Pyruvate

2 Lactate

GL

YC

OL

YS

IS

GL

YC

OL

YS

IS

NADH

NAD+

2

2

NADH2

NAD+2

2 Pyruvate

2 Ethanol

Glucose

CO22

released

2 2

Biosynthesis

Cells, tissues, organisms

Proteins Fats Carbohydrates

Glucose

ATP needed to drive biosynthesis

CITRICACID

CYCLE

AcetylCoA

GLUCOSE SYNTHESIS

Pyruvate

Amino acids Glycerol SugarsFatty acids

Amino groups

G3P

ATP