1. RESPIRATION
© 2016 Paul Billiet ODWS

2. 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-).
© 2016 Paul Billiet ODWS

3. Energy transformations
Light  Chemical (mostly in chemical bonds)
Chemical  Heat
Chemical  Kinetic (movement)
Chemical  Chemical COUPLED REACTIONS e.g. Food  ATP.
© 2016 Paul Billiet ODWS

4. The energy in Adenosine Triphosphate (ATP)
ADP + Pi  ATP + H2O E = kJ mol-1
Inorganic phosphate
ADENOSINE  P  P  P
High energy bond
© 2016 Paul Billiet ODWS

5. A stepwise energy release is needed
Complete oxidation of glucose
C6H12O6 + 6O2  6CO2 + 6H2O E = 2880 kJ mol-1
Complete oxidation of a fat (lipid)
C18H34O O2  18CO2 + 17H2O E = 9800 kJ mol-1
© 2016 Paul Billiet ODWS

6. 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
© 2016 Paul Billiet ODWS

7. 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).
© 2016 Paul Billiet ODWS