ANAEROBIC RESPIRATION Flashcards
What is anaerobic respiration? (1)
the process by which substrate molecules are broken down in cells to release energy in the form of ATP in the absence of oxygen.
what is the first effect of the lack of oxygen in anaerobic respiration? (1)
if oxygen is the final hydrogen acceptor, then without it the carriers of oxidative phosphorylation will all become reduced and the flow of electrons and protons will cease. This will also mean that the supply of NAD+ will be halted and the krebs cycle will also come to a stop.
what is the only stage functioning in anaerobic respiration? (1)
glycolysis
what is the main difference in the amount of ATP produced in both aerobic and anaerobic respiration? (1)
there is a net gain of only 2 ATP per glucose molecule compare with about 38 ATPs from aerobic respiration.
what is the second consequence of lack of oxygen in anaerobic respiration? (1)
the end-product of glycolysis, pyruvic acid, will begin to accumulate, as the concentration of pyruvic acid increases it is channelled into other biochemical pathways.
what does the build of pyruvic acid lead to in animals? (1)
in animals cells this results in the formation of lactate (lactic acid) as the pyruvate acts as the acceptor for reduced NAD.
what does the build of pyruvic acid lead to in plant cells? (1)
in plant cells ethanal reacts acts as this acceptor and this results in the formation of ethanol. These molecules allow glycolysis to continue.
what is alcohol fermentation? (1)
forms carbon dioxide and ethanol as waste products
what is lactate fermentation? (1)
forms lactate as waste products
why do muscles respire anaerobically? (1)
active vertebrate have a high oxygen demand, if the continue to work at a high rate their demand for oxygen quickly exceeds the maximum rate of supply. This means that the concentration of lactate begins to rise.
what is the effect of lactate in muscles? (1)
the effect of this lactate is to gradually inhibit the muscle contractions.
what is the effect of lactate build practically? (3)
-fatigue when we continue exercise for a long time
-painful muscles
-when we rest after exercise muscles can begin to feel quite stiff
what happens to the build up of lactate in muscles after exercise? (1)
the lactate is slowly transported to thee liver where it is converted back to sugars and used in glycolysis
