1. CONCEPT OF RESPIRATORY CHAIN
-ANUSHA SHARMA
(@nu)

2. What is respiration?
 The act or process of inhaling and exhaling;
breathing. Also called ventilation.
 The oxidative process occurring within living
cells by which the chemical energy of organic
molecules is released in a series of metabolic
steps involving the consumption of oxygen and
the liberation of carbon dioxide and water.

3. What does happen when respiration
occurs?
 The oxygen which is in taken in respiration . It
helps in the process of catabolism
 Catabolism: complex food molecules to small
particles and get converted to acetyl coA

5. Respiration chain
 The energy librated during the oxidation of food
molecules is made available with in
mitochondria as reducing equivalents (NADH
and FADH2)
 Mitochondria contains the respiratory chain
which collects and transport reducing equivalents
directing them to their final reaction with oxygen
to form water

7.  The passage of electrons in ETC is associated with the
loss of free energy ,this free energy is utilized to
generate ATP.
 this respiration chain occurs in the mitochondria in
the inner membrane( matrix, Cristal )

8. Components of respiration chain
 The inner mitochondria membrane can be disrupted
into 5 distinct respiratory or enzyme complex
denoted as complex I, II, III, IV and V .
 . NADH-Q oxidoreductase, succinate-Q reductase,
Q-cytochrome c oxidoreductase, and
cytochrome c oxidase are also called Complex I, II,
III, and IV, respectively

9.  And complex V is responsible for ATP synthesis
 Pyruvate and alpha –ketoglutarate dehydrogenase
and feS are other components

10. Complex of ETC

11. Complex 1
 Has NADH binding site
 NADH reductase activity
 NADH - NAD+
 NADH ---> FMN--->FeS---> ubiquinone
 ubiquinone ---> ubiquinone H2
 4 H+ pumped/NADH

13. Complex II
 succinate ---FAD—ubiquinone
 Contains coenzyme Q
 FADH2 binding site
 FAD reductase activity
 FADH2 -- FAD

15. Complex III
 ubiquinone - ubiquinone ox
 while cyt C gets reduced
 Also contains cytochromes b
 proton pump 4H+
 Adds to gradient
8 H+ / NADH
4 H+ / FADH2

17. Complex IV
 reduction of oxygen
 cytochrome oxidase
 cyt a+a3 red ---> oxidized state
 oxygen ---> water
 2 H+ + 2 e- + ½ O2 -- 2 H2O
 transfers e- one at a time to oxygen
 Pumps 2H+ out
 Total of 10 H+ / NADH
 Total of 6 H+ / FADH2

19. Totals
 Proton gradient created as electrons transferred to
oxygen forming water
10 H+ / NADH
6 H+ / FADH2

20. Complete mechanism