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49 Cards in this Set
- Front
- Back
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What is glucose first hydrolysed to during glycolysis and how? |
Glucose phosphate by phosphorylation |
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What is the second stage of glycolysis? |
Hydrolysis of glucose phosphate into triose phosphate |
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What is the third stage of glycolysis? |
Oxidation of triose phosphate |
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What are the 3 respiratory substrates? |
Glucose Amino acids Lipids |
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What are the coenzymes involved in respiration? |
NAD and FAD |
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What happens to coenzyme NAD and FAD during respiration? |
Become reduced by picking up hydrogen atoms and become oxidised when they lose them again |
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Why are coenzymes needed for respiration? |
Needed for some enzymes (dehydrogenases) to work |
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What do dehydrogenase enzymes do? |
Remove H from a molecule |
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What is the balanced symbol equation for aerobic respiration? |
C6H12O6 +6O2 --> 6CO2 +6H2O +ATP |
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What is the first stage of respiration? |
Glycolysis |
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Where does glycolysis occur ? |
Cytoplasm |
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Why is glycolysis common to both aerobic and anaerobic respiration? |
No oxygen is needed |
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What is the main occurrence in glycolysis? |
Glucose (6C) converted to pyruvate (3C) |
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Why is glucose phosphorylated to glucose phosphate? |
Makes the glucose more reactive Traps the glucose within the cell so can't diffuse back out |
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How many ATP are needed to phosphorylate glucose to glucose phosphate? |
2 |
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What happens during the oxidation of triose phosphate? |
Each loses 2 H atoms (dehydrogenase needed) NAD gains these atoms and becomes reduced The reduced NAD goes to the electron transport chain if oxygen is available |
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What happens in stage 4 of glycolysis? |
Production of ATP |
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How many ATP are produced in one glycolysis? |
4 |
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What is the net gain of ATP from glycolysis and why? |
2 4 made but 2 used initally to phosphorylate glucose to glucose phosphate |
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What are the final products of glycolysis? |
2 X Pyruvate 4 X ATP 2 X reduced NAD |
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By what process are the 4 ATP produced in glycolysis? |
Substrate level phosphorylation |
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What can happen once glucose has been converted to pyruvate? |
Can now enter mitochondria |
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Where does the link reaction occur? |
Matrix of mitochondria |
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What is the main occurrence in the link reaction? |
Pyruvate is converyed to acetylcoenzymeA. |
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What is the first part of the link reaction? |
Pyruvate is oxidised into acetate reducing NAD and producing CO2 by decarboxylation |
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What is decarboxylation? |
The removal of carbon in the form of CO2. |
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What is the second part of the link reaction? |
Acetate combines with coenzyme A to produce acetylcoenzymeA |
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What are the products of link reaction? |
acetylcoenzymeA CO2 Reduced NAD |
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Where does the Krebs cycle occur ? |
Matrix of the mitochondria |
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Where does the link reaction occur? |
Matrix of the mitochondria |
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What happens in the Krebs cycle? |
acetylcoenzymeA combines with a 4 carbon molecule to produce a 6 carbon molecule Oxidation and reduction occurs producing 3 reduced NAD and 1 reduced FAD 1 ATP is produced per cycle by substrate level phosphorylation CO2 is lost by decarboxylation |
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What are the products of the Krebs cycle? |
ATP 3 X reduced NAD 1 X ATP3 X reduced NAD1 X reduced FAD2 X CO2 ATP3 X reduced NAD1 X reduced FAD2 X CO2 1 X reduced FAD 2 X CO2 2 X CO2 |
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What are the 2 ATP used for at the start of glycolysis? |
To phosphorylate glucose into glucose phosphate |
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What is the second stage of glycolysis? |
Hydrolysis of glucose phosphate into triose phosphate |
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What happens to reduced coenzymes? |
Go to electron transport chain if oxygen is available |
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How are lipids used at respiratory substrates? |
First hydrolysed into fatty acids and glycerol by lipase Glycerol is converted into triose phosphate and enters glycolysis Fatty acids: the long hydrocarbon chain is hydrolysed into 2C fragments that are converted into acetylcoenzymeA which can then enter the Krebs cycle |
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How are proteins used as respiratory substrates? |
First hydrolysed into amino acids using proteases. The amino group is removed (deamination) and the remainder of the molecule can enter respiration at different places: Some with 3C can be converted to pyruvate and enter the link reaction Some with 4C or 5C can enter Krebs cycle |
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When are proteins used as a respiratory substrate? |
When carbohydrate and lipid (fat) reserves have been exhausted |
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Where does the electron transfer chain occur? |
Inner mitochondrial membrane |
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By what process is ATP produced in the electron transport chain? |
Oxidative phosphorylation |
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What theory can explain the electron transfer chain? |
Chemiosmotic theory |
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Where does anaerobic respiration occur? |
Cytoplasm |
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Why must NAD be reoxidised in anaerobic respiration? |
To allow glycolysis to continue as there is only a limited supply of NAD |
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What stage of respiration still takes place in anaerobic respiration? |
Glycolysis |
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What is pyruvate converted to in anaerobic respiration in animals? |
Lactate (lactic acid) |
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What is pyruvate converted into during anaerobic respiration in plant cells? |
Ethanol and CO2 |
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How much ATP is produced in anaerobic respiration? |
2 |
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What happens when oxygen becomes available again after anaerobic respiration in animals and why? |
Lactate can be converted back to pyruvate as it's only a partial breakdown of glucose |
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Why is pyruvate converted into lactate in animals and ethanol and CO2 in plants during anaerobic respiration? |
So reduced NAD can be reoxidised |
