110150309 tissue respiration

8/12/2019 110150309 Tissue Respiration

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Tissue Respiration

By Jodi-Ann Fletcher


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Explain:

The conversion of carbohydrates into a hexose

sugar, usually glucose which is the oxidised to

produce energy in the form of ATP, carbon

dioxide and water.


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Respiration

Catabolic process- product have less energy

than reactant

Produces phosphorylated nucleotide- ATP

Exergonic reaction


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Why ATP?

Releases small, manageable doses of energy

ATP is small

Soluble

Easily transported within cell

Making ATP reversible- when broken energyreleased

Single step reaction; one enzyme needed; easilycontrolled

Each cell makes its own ATp


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ADP phosphorylation is a condensation reaction

Both involve ATPase

30.6KJmol-1 energy involved


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How ATP Made?

Chemiosmosis1. Uses electrical potential energy

2. In phosphorylation of photosynthesis

3. In oxidative phosphorylation of respiration

Substrate-level phosphorylation1. Occurs by obtaining phosphate group from an

intermediate.

2. Energy released by reorganising chemical bonds allows for

the transfer of Pifrom phosphorylated compound to ADP.


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Chemiosmosis

matrix

Mitochondrion

inner membrane


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Chemiosmosis

Chemiosmosis refers to the diffusion of ions

across a partially permeable membrane

usually referring to H+ gradient so that when

it dissipates the energy released is used to

drive the phosphorylation of ADP.


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Glucose and Respiration

Too much energy expelled at one time

(volatile)

Unreactive

Needs to be active

Glucose phosphorylated.


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1.All respiration does not require oxygen (think

anaerobic)

2.Respiration is not one reaction (think glycolysis,

link rxn, krebs cycle, oxidative phosphorylation)

3.Glucose is not the only respiratory substrate(think starvation: fats, protein)


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Glycolysis

Glucoseactivated (phosphorylated)- 1 ATP-

glucose-6-phoshateforms

Isomerisation to fructose-6-phosphate

Phosphorylation to fructose bisphosphate, 1 ATP

Lysis to two triose phosphates

Oxidation to two glycerate-3-phosphate, 2NADH,

2 ATPper triose

Phosphorylation to two pyruvate, 2ATP


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Glycolysis

Occurs in cytoplasm

No oxygen needed

Glucose activated, no longer canleave cell

Lysis to form 2 triose phosphates

ATP formed from oxidation viasubstrate level phosphorylation


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Glycolysis Reactants Products

Respiratory substrate (6C)

(glucose)

2 pyruvate (3C)

2ATP 4ATP

2NAD 2NADH


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Linked reaction

In matrix

Energy cost to go into mitochondrion

Pyruvate is decarboxylated and oxidised togive an acetyl group.

The acetyl group is carried to the next stage by

the coenzyme A as acetyl CoA.

2 carbon dioxide produced per glucose

2 NADH produced per glucose


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Linked Reaction Reactants Products

2 Pyruvate (3C) 2 carbon dioxide

Coenzyme A Acetyl CoA (2C)

2NAD 2NADH


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Krebs Cycle


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Krebs Cycle

Matrix of mitochondrion

Acetyl group (2C) combines with (4C)oxaloacetate

(6C) citrate formed 2 decarboxylation reactions occur

4 dehydrogenation reactions occur

use NAD and uses FAD per cycle

1 ATP formed per cycle Oxaloacetate reformed

2 cycles `


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KREBS CYCLE Reactants Products

oxaloacetate oxaloacetate

2Acetyl CoA 4 Carbon dioxide

6NAD 6NADH

2FAD 2FADH

2ADP + 2Pi 2 ATP


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Thus far:

C6H12O6+ 6H2O

6CO2+ 12H2+ 4 ATP(Water used is decarboxylation and gives

off oxygen with the carbon to form

carbon dioxide)


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Significanceof Krebs Cycle

Degradesmacromolecules- 3C pyruvateCO2

Provides reducing power for electron

transport chain

Its an interconversion centre- valuable source

of intermediate compounds used in the

manufacture of other substances.


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OXIDATIVE PHOSPHORYLATION

(electron transport chain)

Occurs on the cristae of mitochondrion

Means by which reducng power (H2)converted to ATP.

H2 atoms passed down chain of other carriersof progressively lower energy levels fromNADH and FADH.

During transport, energy lost.

Energy released used to makeATP(chemiosmosis)


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ETC

Intially H2atoms passed down chain

H2dissociates into H+(protons) and electons

Electrons pass from carrier to carrier still

At end of chain, protons and electrons recombine

H2atoms react with oxygento form water

The formation of ATP through oxidation of

hydrogen atoms called oxidative phosphorylation.


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ETC

Oxygen is the final hydrogen acceptor

The transfer of hydrogen atoms to oxygen is

catalysed by the enzyme cytochrome oxidase

The ETC is a series of redox reactions.

NB cytochrome oxidase made of copper which

can easily combine with cyanide rather than

oxygen


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Oxidative Phosphorylation


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12H2+6O212H20+ 34 ATP

2H2+ O22H2O + energy

Some energy used to make ATP

Energy released in a series of reactions calledthe respiratory chain (ETC)

For each NADH 3 ATP made

For each FADH( enters lower in chain) 2ATPmade.


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LETS SUM THIS UP!!!!!(man i need

to go to physics)

C6H12O6+ 6H2O6CO2+ 12H2+ 4ATP

12H2+ 6O212H2O+ 34 ATP

SUBTRACT Mitochondrion shuttle for pyruvate 2ATP

(theory)

ADP need to go into cytoplasm too Therefore:


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Tissue Respiration (Aerobic)

C6H12O6+ 6O26CO2+ 12H2+ 6H2O+ 36ATP

1NADH- 2.5 ATP

1FADH-1.5 ATP


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110150309 tissue respiration

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