1. F. Electron Transport Chain [ETC]
1. Overview
a this occurs in the cristae membrane of the mitochondria
b. a series of oxidation reduction reactions that converts the stored energy in NADH+H+ or FADH2 indirectly into ATP
c. the process involves moving electrons between proteins within the membrane and this results in proton movement across the membrane

2. 2. Accessing the NADH+H+ and FADH2
Kreb’s cycle occurs in mitochondrial matrix 
2 x 3 NADH+H+
2 x 1 FADH2
oxidation of pyruvate occurs in mitochondria matrix 
2 x 1 NADH+H+
glycolysis occurs in the cytoplasm
1 x 2 NADH+H+

3. 3. Getting the energy into the mitochondria from the cytoplasm
NADH+H+ from the cytoplasm can not pass through the inner mitochondrial membrane and therefore can not directly enter the ETC
however, the energy stored in NADH+H+ can be passed across the membrane with the electrons to a molecule of FADH2

4. glycerol phosphate shuttle protein
NADH+H+
FAD
2H+
2e-
FADH2
NAD+
inner mitochondrial membrane

5. 1 – NADH dehydrogenase 2 – protein Q 3 – cytochrome b-c1
ELECTRON TRANSPORT CHAIN
1 – NADH dehydrogenase 2 – protein Q – cytochrome b-c1
4 – cytochrome C 5 – cytochrome oxidase 6 – ATP synthase 1 2 3 4 5 6

6. 2H+ 2H+ 2H+ 2H+ FADH2 ½ O2 + 2H+ NADH + H+ FAD NAD+ H20 ADP + Pi 2H+1 2 3 4 5 6
2e-
FADH2
½ O2 + 2H+
NADH + H+
FAD
NAD+
H20
2H+
ADP + Pi
2H+
2H+
ATP
2H+

7. 4. Proteins
a. NADH dehydrogenase – accepts 2 electrons from NADH+H+ and passes them on - 2 H+ [protons] follow the electrons & pass through the membrane
b. protein Q - accepts 2 electrons from NADH dehydrogenase or FADH2 and passes them on
c. cytochrome b-c1 complex - accepts 2 electrons from protein Q and passes them on - 2 H+ [protons] follow the electrons & pass through the membrane

8. d. cytochrome c - accepts 2 electrons from cytochrome b-c1
d. cytochrome c accepts 2 electrons from cytochrome b-c1 complex and passes them on
cytochrome oxidase complex -
- accepts 2 electrons from cytochrome c & passes them on to oxygen [1/2 O2]
- 2 H+ follow the electrons & pass through the membrane

9. 6. tally of H+ across the membrane
a. for every NADH+H+  3 pairs of H+ are pumped into the intermembrane space
b. for every FADH2  2 pairs of H+ are pumped into the intermembrane space

10. 7. ATP synthetase [not technically part of the ETC]
a. there are more H+ in the intermembrane space than in the matrix
b. the H+ try to move down a concentration gradient back across the membrane
c. the H+ can not pass through the phospholipid membrane directly
d. the enzyme ATP synthetase allows the H+ to pass through it
e. as the H+ pass through the ATP synthetase they distort its shape
and when it returns to its normal shape it is able to add Pi + ADP  ATP + H2O

11. 8. Summary
pg 108 Fig for information
9. Overall summary
pg 110 Fig 25 recommend copying this

12. chloroplast SUMMARY OF PHOTOSYNTHESIS and AEROBIC RESPIRATION glucose
mitochondria

13. light CO2 light reaction C-4 cycle ATP; NADPH +H+ Calvin cycle H2O O2
chloroplast O2
cellulose
glucose

14. glucose O2 ATP glycolysis H2O NADH + H+ pyruvate CO2 FADH2 FAD
oxidation of pyruvate
ETC
NADH + H+
Kreb’s cycle
FADH2
mitochondria
ATP
ATP
CO2