ch18 - anaerobic respiration

After glycolysis, when there is a lack of oxygen, what process occurs instead of the links reaction

Anaerobic respiration

Why does anaerobic respiration take place instead when oxygen levels are low 

Because anaerobic respiration does not require oxygen

why can the other stages of aerobic respiration not occur when there is a lack of oxygen 

Oxidative phosphorylation will not be able to occur hence neither will link reaction and krebs cycle

What are the two types of anaerobic respiration and what organisms do they take place in 

Lactic acid/ lactate fermentation - animals 

Alcohol fermentation - yeast and many plant cells 

How many ATP are made during anaerobic respiration 

2xATP through glycolysis 

Where does lactic acid fermentation take place

In the cytoplasm of animal muscle cells 

What are the 3 processes of lactic acid fermentation

-oxidation =NADH is oxidised into NAD releasing hydrogen 

-reduction =pyruvate is reduced because it accepts the hydrogen forming lactate, this reaction is catalysed by lactate dehydrogenase 

-regeneration = as NAD is regenerated so it can be reused in glycolysis so glycolysis can continue 

Why is lactate insufficient long term 

-the small amount of ATP produced is not sufficient to maintain vital processes 

Why is lactate toxic 

As it accumulates it leads to muscle fatigue as well as decreasing pH causing proteins such as enzymes to denature 

What is oxygen debt 

The amount of oxygen needed to break down lactate

What does the body do with lactate once its formed 

its transported in the bloodstream to the liver where it reacts with oxygen to regenerate glucose

Once glucose is regenerated what are the two possible pathways it can take

renter glycolysis OR be stored as glycogen 

Why is lactic acid fermentation a reversible reaction

Because no CO2 is lost so the lactic acid can be regenerated into pyruvate (through glycolysis) when oxygen is available 

Where does alcohol fermentation take place

In the cytoplasm of yeast and plant cells 

What are the 3 processes of alcohol fermentation

-decarboxylation= CO2 is removed from pyruvate forming ethanal 

-oxidation =NADH is oxidised into NAD releasing hydrogen 

-reduction =ethanal is reduced because it accepts the hydrogen forming ethanol

-regeneration = as NAD is regenerated so it can be reused in glycolysis so glycolysis can continue

Why is alcohol fermentation an irreversible reaction

Because CO2 is lost so the ethanol cannot be regenerated into pyruvate instead it is removed as a waste product