The release of energy from substrates such as glucose in the absence of oxygen.
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What happens if oxygen is absent?
The electron transport chain cannot function, so the link reaction and Krebs cycle also stop.
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What is the only source of ATP left?
Only the anaerobic process of glycolysis.
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What is neccessary for glucose to keep working?
The reduced NAD, generated during the oxidation of glucose has to be reoxidised.
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What are the 2 pathways to reoxidise reduced NAD for eukaryotic cells?
Fungi such as yeast use ethanol fermentation and animals use lactate fermentation.
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How is ATP produced?
2 molecules of ATP are made by substrate-level phosphorylation during glycolysis.
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What are the products of glycolysis?
2 molecules of ATP, 2 molecules of reduced NAD and 2 molecules of pyruvate.
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When does lactate fermentation occur?
Occurs in mammalian muscle tissue during vigorous activity such as when running to escape a predator when demand for ATP is high and there is an oxygen deficit.
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What is the hydrogen acceptor in mammals?
Pyruvate
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Is carbon dioxide produced in lactate fermentation?
No
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Is ATP produced in lactate fermentation?
No
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Is NAD reoxidised in lactate fermentation?
Yes
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What are the end products of lactate fermentation?
Lactate
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What enzymes are involved in lactate fermentation?
Lactate dehydrogenase.
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Where is the lactate taken from and to?
From muscles to the liver.
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What happens when more oxygen is available?
The lactate can be converted back to pyruvate that can enter the Krebs cycle via the link reaction or be recycled to glucose.
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What does the enzyme lactate dehydrogenase do?
Catalyses the oxidation of reduced NAD and the reduction of pyruvate to lactate.
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What causes muscle fatigue?
The reduction in pH that will reduce enzyme activity in the muscles.
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In alcoholic fermentation what happens to each pyruvate molecule?
Each pyruvate loses a carbon dioxide, it is decarboxylated and becomes ethanal.
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What is this reaction catalysed by?
The enzyme pyruvate decarboxylase which has a coenzyme bound to it.
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What does ethanal do?
Ethanal accepts hydrogen atoms from reduced NAD which becomes reoxidised as ethanal is reduced to ethanol.
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What catalyses the reduction of ethanal to ethanol?
Ethanol dehydrogenase.
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What can the reoxidised NAD now do?
Can now accept more hydrogen atoms from glucose, during glycolysis.
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What is the hydrogen acceptor in ethanol fermentation?
Ethanol
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Is carbon dioxide product in ethanol fermentation?
Yes
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Is ATP produced in alcoholic fermentation?
No
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Is NAD reoxidised in alcoholic fermentation?
Yes
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What are the end products of alcoholic fermentation?
Ethanol and carbon dioxide.
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What enzymes are involved in ethanol fermentation?
Pyruvate decarboxylase and ethanol decarboxylase.
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Other cards in this set
Card 2
Front
What happens if oxygen is absent?
Back
The electron transport chain cannot function, so the link reaction and Krebs cycle also stop.
Card 3
Front
What is the only source of ATP left?
Back
Card 4
Front
What is neccessary for glucose to keep working?
Back
Card 5
Front
What are the 2 pathways to reoxidise reduced NAD for eukaryotic cells?
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