module 5 - 18.5 anaerobic respiration Flashcards
when does anaerobic respiration happen in mammalian cells?
all the time - it is the balance between aerobic and anaerobic respiration thats important
what is the difference in production between aerobic and anaerobic respiration?
- aerobic - produces net gain of 38 ATP molecules per glucose molecule respired
- anaerobic - produces net gain of 2 ATP molecules per glucose molecule respired
what are obligate anaerobes?
microorganisms killed y normal atmospheric concentrations of oxygen
- has to do anaerobic respiration
what are facultative anaerobes?
organisms that make ATP by aerobic respiration if oxygen is present, but can switch to anaerobic respiration if oxygen is absent
- can do both aerobic and anaerobic respiration
what are obligate aerobes?
organisms that require oxygen to grow
- anaerobic respiration can happen but will only generate ‘emergency ATP’ for a short time
what are yeasts?
single celled fungi
what are the 2 types of anaerobic respiration?
- alcoholic fermentation
- lactate fermentation
what is involved in alcoholic fermentation?
- occurs in yeasts and come plant root cells
- glycolysis in cytoplasm produces net gain of 2 ATP per glucose
- pyruvate is made
- reduced NAD is made
- pyruvate produced is decarboxylated to ethanal by pyruvate decarboxylase to produce carbon dioxide
- ethanal reduced to ethanol by alcohol dehydrogenase by accepting hydrogen from reduced NAD
- reduced NAD oxised back to NAD
what must there be a supply of to keep alcoholic fermentation going?
supply of NAD or NAD+
what is involved in lactate fermentation?
- occurs in mammals
- glycolysis in cytoplasm produces net gain of 2 ATP per glucose
- pyruvate is made
- reduced NAD is made
- pyruvate converted to lactate or lactic acid by lactate dehydrogenase
- reaction involves accepting hydrogen from reduced NAD, reduced NAD oxidised to NAD so it can accept the hydrogen
- lactate is converted back to glucose in the liver by the cori cycle
what does regenerated NAD do?
goes back to glycolysis steps
what is the final reaction in aerobic respiration pathway?
reduction of oxygen to water
rotenone is an insecticide that inhibits the electron transport chain. what are the expected changes caused by rotenone?
oxygen consumption - decreased
lactate concentration - increased
krebs cycle activity - decreased
how does chemiosmosis lead to ATP synthesis?
hydrogen ions diffuse from inner to outer membrane and out through ATP synthase
cells in culture were supplied with radioactively-labelled oxygen gas. which cell metabolite will show most radioactivity after a few minutes?
water
