Powerpoint Presentation: Respiration and Energy

advertisement

RESPIRATION

Energy in food

Carbohydrates (17 kJ g

-1

)

Proteins (17 kJ g

-1

)

Lipids (34 kJ g

-1

)

These are sources of reduced carbon

This can supply hydrogen atoms

 protons (H

+

) + electrons (e

-

)

© 2010 Paul Billiet

ODWS

Energy transformations

Light

Chemical (mostly in chemical bonds)

Chemical

Chemical

Chemical

Heat

Kinetic (movement)

Chemical

COUPLED REACTIONS

e.g. Food

ATP

© 2010 Paul Billiet

ODWS

The energy in Adenosine

Triphosphate (ATP)

ADP + Pi

ATP + H

2

O

E = + 30.5 kJ mol

-1

Inorganic phosphate

ADENOSINE

P

P

P

High energy bond

© 2010 Paul Billiet

ODWS

A stepwise energy release is needed

Complete oxidation of

glucose

C

6

H

12

O

6

+ 6O

2

6CO

2

+ 6H

2

O

E = 2880 kJ mol

-1

Complete oxidation of a

fat (lipid)

C

18

H

34

O

2

+ 25.5O

2

18CO

2

+ 17H

2

O

E = 9800 kJ mol

-1

© 2010 Paul Billiet

ODWS

Respiration is efficient

This is too much to handle all at once

Energy is released step by step

Coupled to ATP synthesis

The energy in 1 molecule of glucose is used to synthesise 36 molecules of ATP

37.5 % efficient

This is a very efficient energy conversion

Because the release of the energy from the food molecules is done stepwise

© 2010 Paul Billiet

ODWS

Coupling the energy released from glucose to ATP

Two reaction pathways

GLYCOLYSIS

in the cytoplasm

KREB'S CYCLE

in mitochondria of eukaryotes (in the cytoplasm of prokaryotes)

© 2010 Paul Billiet

ODWS

Download