Anaerobic Respiration Flashcards
If our body doesn’t have enough oxygen what happens to respiration
-it becomes anaerobic and the Link reaction, the Krebs cycle and oxidative phosphorylation doesn’t occur
What is anaerobic respiration known as and why
-the final survival mechanism because it provides just enough ATP for us to have our normal functions (e.g muscle contraction)
What is anaerobic respiration
Respiration in the absence of oxygen
What is fermentation
The breaking down of large complex molecules to simpler molecules without the use of oxygen or the electron transfer chain
What is the two types of anaerobic respirations
1) lactate fermentation
2) ethanol fermentation
What organism does lactic fermentation takes place in
Animals
What organism does ethanol fermentation take place in
Plants
Describe the features of lactate fermentation
-lactate = lactic acid
- the process is reversible
-glycolysis (in the cytoplasm) is still the first stage as it occurs in aerobic or anaerobic conditions
-if there isn’t enough O2 it will stay in the cytoplasm and undergo fermentation
When is lactate made
During intense exercise when we don’t have enough oxygen
Describe the process of lactate fermentation
1) Pyruvate starts the reaction, which came from glycolysis
2) NADH is oxidised and Pyruvate accepts the 2H atoms, the reaction is catalysed by lactate dehydrogenase
3) which produces lactate and NAD
4) lactate can’t stay in the cells as it will start to denature enzymes and proteins giving us muscle fatigue
5) so it goes to the liver and reacts with O2 to regenerate glucose
6) glucose can then undergo glycolysis again to produce pyruvate continuing the cycle
Describe the feature of ethanol fermentation in plants/yeast
-irreversible process
Describe the process of ethanol fermentation
1) Pyruvate is decarboxylated and converted to ethanal, the reaction is catalysed by lactate decarboxylase
2) NADH is reduced and ethanal accepts the hydrogen and is reduced to ethanol, with the reaction being catalysed by ethanol dehydrogenase and NAD is also produced
3) NADH is re-oxidised and made available to accept more hydrogen atoms from triose phosphate allowing glycolysis to continue
Why is ethanol beneficial to humans
You can use it to make food (yeast for bread, beers and wine etc)
Why can you not get drunk from eating bread
Because ethanol evaporates when making bread in the oven
At what % does ethanol kill the yeast
15%
