Whats wrong with the glucose created during photosynthesis?
Unable to be used directly by the cell as an energy source
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What happens instead ?
They must use ATP as their immediate energy source
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When is the breakdown of glucose and formation of ATP carried out?
During respiration
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What are the 2 diff forms?
Aerobic- requires oxygen and produces CO2 and water
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Other
Anaerobic- takes place in the absence of oxygen and produces lactate in animals or ethanol and carbon dioxide in plants and fungi
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What is there less of in anaerobic than aerobic?
ATP
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Why is this not efficient?
Molecules still have lots of energy locked up
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4 stages of aerobic?
Glycolysis, Link reaction, Krebs cycle, oxidative phosphorylation
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Glycolysis?
Splitting of the 6 carbon glucose into two 3-carbon pyruvate in the cytoplasm (not mitochondria)
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link reaction?
The 3 carbon pyruvate enters a series of reactions and 2-carbon acetylcoenzyme A is formed.
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Why link?
Links cytoplasm to mitochondria
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Krebs cycle?
aka as citric acid cycle. Acetylcoenzyme A enters a cycle of redox reactions that yields a small amount of ATP and large amount of reduced NAD and FAD- carrying H to next stage
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Oxidative phosphorylation?
Electrons from reduced NAD and FAD are released ETC and synthesis of ATP. Water is formed as a by-product
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How much ATP in each stage?
2, 0, 2, 32
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What is glycolysis?
First stage of aerobic and anaerobic , enzyme controlled
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Where does it occur?
Cytoplasm of cells and is the process by which a hexose sugar (glucose) is split into 2 molecules of 3 carbon pyruvate in series of rxn's
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First stage?
Phosphorylation of glucose
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Why?
Glucose needs to be made more reactive before it is split (stable molecule) so it is phosphorylated by the addition of 2 phosphate groups
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Where do these phosphate groups come from?
Hydrolysis of 2 molecules of ATP (-2atp)
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What does this do?
Lowers activation energy for subsequent enzyme controlled reactions (by making it more reactive)- glucose stable molecule so makes it more likely to react
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What is the 2nd stage?
Splitting of phosphorylated glucose by enzyme
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What happens?
Each glucose molecule is split into 2 molecules of 3 carbon triose phosphate
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3rd stage?
Oxidation of triose phosphate
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how
Triose phosphate is oxidised by the removal of hydrogen. H transferred to carrier molecule called NAD hence reduced NAD (NADH) is formed
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Last stage?
Production of ATP
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how?
Enzyme controlled reactions convert the triose phosphate into another 3-carbon molecule called pyruvate and 2 molecules of ATP are generated in this process
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Overall
Glucose-Triose phosphate using 2ATP into 2ADP+Pi. 2 Triose phosphate into 2 pyruvate losing 2 H (H per TP) therefore 2 Reduced NAD and 4 ATP (2 per TP)
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Gross ATP Net ATP
4, 2
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Net gain
2 ATP, 2 reduced NAD, 2 pyruvate
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Other cards in this set
Card 2
Front
What happens instead ?
Back
They must use ATP as their immediate energy source
Card 3
Front
When is the breakdown of glucose and formation of ATP carried out?
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