RESPIRATION

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  • Created by: romy kale
  • Created on: 11-12-13 13:40

ATP- Why is it useful??

1) Energy released in small amounts

2) ATP is soluble

3) Involves a single reaction

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Aerobic Respiration- Glycolysis

Glucose (6c)------------------------> 2 x Pyruvate (3c)

  • Occurs in cytoplasm of the cell
  • Glucose activated by phosporylation. Requires hydrolysis of ATP to ADP to provide the phosphate 
  • Phosphorylated glucose is then split into two TP
  • TP then oxidised to pyruvate, involves loss of a hydrogen which reduces the NAD to NADH2.
  • ATP also produced directly 

Yields:

2 ATP

2 NADH2

2 PYRUVATE

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Link Reaction

Pyruvate (3c) + NAD + coA ---------------------------> Acetyl coA (2c) +NADH2 + CO2

  • energy from Pyruvate converted to acetyl coA
  • Involves oxidation of pyruvate and H lost reduces the NAD to produce NADH2

Yields:

NADH2 will be used to produce ATP by oxidative phosphorylation

2 x Acetyl coA

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Kreb's Cycle

Acetyl coA now fed into a series of redox reactiobs which occur in the MATRIX of the mitochodria

The kreb's cycle yields:

  • CO2
  • ATP produced directly
  • NADH2 and FADH2 produced to be used in oxidative phosphorylation
  • krebs cycle occurs twice
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Electron Transport chain

 1- Reduced NAD/FAD provide

 2- H+ ions which move across membrane

3- e- move down ETC by  series of redox reactions;

4 - energy made available as electrons passed on;

5- H+ passed into intermembrane space;

6- H+ flow back through enzyme; 

7- energy used to synthesise ATP from ADP and phosphate;

8- Oxygen is final electron acceptor 

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Anerobic respiration (in absence of oxygen)

  • Link, kreb's and ETC stop as no oxygen to act as final electron acceptor
  • Glycolysis doesnt require oxygen but needs regenerated NAD to continue
  • H from the NADH2 is now accepted by pyruvate rather than passing through the ETC
  • Pyruvate is therefore reduced to lactate in animals and ethanol in plants

1 only 2 ATP’s produced per glucose;

2 Glycolysis only;

3 Glucose to 2 pyruvate;

4 Energy released used to synthesise 2ATP;

5 and 2NADH;

In animals

6 pyruvate is reduced to lactate

In plants/microorganisms

7  pyruvate is reduced to ethanol 

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