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Powerpoint Templates Page 2 1.Understand the chemiosmotic theory. 2. Determine the inhibitors of the resp. chain. 3. Understand the concept of shuttles across the mitochondrial membrane.

Powerpoint Templates Page Peter Mitchell Proposed chemiosmotic hypothesis

Powerpoint Templates Page 4 The theory postulates that the energy obtained from oxidation is coupled to the translocation of protons H+ from the mitochondrial matrix to the inter- mitochondrial space. Complexes I,III,IV act as proton pumps.

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Powerpoint Templates Page 6 ATP synthase F1 F0 Scattered on the surface of the inner mitochondrial membrane are units of the ATP- synthase.

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Powerpoint Templates Page 8 I:\YouTube - Gradients (ATP Synthases).flvI:\YouTube - Gradients (ATP Synthases).flv

Powerpoint Templates Page 9 No. of ATP molecules produced No. of Oxygen atoms consumed If we start from NADH = 3:1 If we start from FADH2 = 2:1 Uncoupler = zero

Powerpoint Templates Page 10 There is no mechanism for storage of ATP. All ATP present at any moment is only enough to meet the needs of the body for few seconds. For this reason, there must be an efficient and controlled way for the production of ATP.

Powerpoint Templates Page 11 Respiratory control 1.Mainly by availability of ADP. (ATP/ADP transporters may be rate limiting at certain times). 2.Availability of electrons : NADH/NAD ratio or FADH2/FAD. 3. Availability of O2.

Powerpoint Templates Page 12 I:\Electron Transport Chain III.swf

Powerpoint Templates Page 13 A- Uncouplers

Powerpoint Templates Page 14 They act by transporting H+ to inside the mitochondria without passing through F ₀ F 1 And energy is released as heat.

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Powerpoint Templates Page 17 B- inhibitors of ETC proper:

Powerpoint Templates Page 18 Completely blocks F ₀ so it inhibits ATP synthesis Example: oligomycin (antibiotic) C-Inhibitors of phosphorylation: D- ATP/ADP transporters inhibitors

Powerpoint Templates Page 19 Name FunctionSite of Action Rotenone e – transport inhibitorComplex I Amytal e – transport inhibitorComplex I Antimycin A e – transport inhibitorComplex III Cyanide e – transport inhibitorComplex IV Carbon Monoxide e – transport inhibitorComplex IV Azide e – transport inhibitorComplex IV 2,4,-dinitrophenol Uncoupling agenttransmembrane H + carrier Pentachlorophenol Uncoupling agenttransmembrane H + carrier Oligomycin Inhibits ATP synthase ATP synthase

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Powerpoint Templates Page 22 All of the following statements about the enzymic complex that carries out the synthesis of ATP during oxidative phosphorylation are correct except: (A) It is located on the matrix side of the inner mitochondrial membrane (B) It is inhibited by oligomycin (C) It can exhibit ATPase activity (D) It can bind molecular O2

Powerpoint Templates Page 23 ADP ATP

Powerpoint Templates Page 24 Glycerol 3 Phosphate Shuttle

Powerpoint Templates Page 25 Malate Aspartate Shuttle

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Powerpoint Templates Page 27 Mitochondrial DNA Circular DNA Derived from mother’s ovumA It contains 37 genes 13 proteins of ETC 22 tRNA 2rRNA

Powerpoint Templates Page 28 Mitochondrial abnormalities

Powerpoint Templates Page 29 Reduced NADH generated in the cytoplasm is able to pass its electrons to oxygen through the mitochondrial electron transport system by which of the following mechanims? A) A specific transport system enables NADH to pass through the mitochondrial membrane. B) NADH reduces FAD to FADH2, which then passes through the mitochondrial membrane. C) NADH reduces dihydroxyacetone photphate to glycerol phosphate, which can pass through the mitochondrial membrane. D) NADH reduces membrane-bound NADP to NADPH, which passes electrons to coenzyme Q. E) NADH oxidizes aspartate to oxaloacetate, which can enter the mitochondria.

Powerpoint Templates Page 30 Which of the following statements about the electron transport chain is correct? a) The electron transport chain is made up of a chain of electron carriers with decreasing electron affinity. b) The electron transport chain is made up of a chain of electron carriers with increasing redox potential. c) The electron transport chain is made up of a chain of electron carriers with decreasing oxidising power. d) The electrons transferred from carrier to carrier in the electron transport chain gain energy.

Powerpoint Templates Page 31 Which of the following statements about the generation of ATP in the electron transport chains is correct? a) The F 1 subunit of the ATP synthase contains the motor which is driven to rotate by the proton flow. b) The F 1 subunit of the ATP synthase contains the catalytic centre that synthesizes ATP. c) The F 0 subunit of the ATP synthase binds ADP and Pi tightly before ATP synthesis occurs. d) The F 0 subunit of the ATP synthase contains the catalytic centre that synthesizes ATP.

Powerpoint Templates Page 32 How does atractyloside affect mitochondrial respiration?... If you isolate mitochondria and place them in buffer with a low pH, they begin to manufacture ATP. Why?

Powerpoint Templates Page 33 -Loss of electrons from one substance is called: a-Oxidation b-Reduction c-Dehydrogenation d-Phosphorylation

Powerpoint Templates Page 34 -Living cells generate ATP by: a- Oxidative phosphorylation b- Substrate level phosphorylation c- Both of the above d- none of the above

Powerpoint Templates Page 35 -ATP- Synthase is a membrane protein complex with it's knob facing mitochondrial matrix is powered by: a- the flow of hydrogen ions b- ATP c- ADP d- Pi

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