1. anaerobic respiration

ALTERNATIVES FOR PYRUVATE

ANAEROBIC RESPIRATION-1

• reduced NAD is used to convert pyruvate into lactate (rather than entering the ETC)

• pyruvate is reduced and reduced NAD is oxidised

• lactate lowers pH of blood, which affects CNS

• so muscle contractions are affected and muscles become fatigued

ANAEROBIC RESPIRATION- 2

• after exercise, lactate needs to be oxidised back into pyruvate

• pyruvate can then enter Krebs cycle and be respired aerobically to produce CO2, H2O and lots of ATP

• O2 is needed to oxidise lactate so you continue to breathe deeply for some time after exercise

DIFF BETWEEN O2 DEMAND AND O2 AVAILABLE- GRAPH

EPOC

• after strenuous exercise, we continue to breathe deeply to get as much O2 into body- to provide O2 to oxidise lactic acid that has built up during anaerobic resp- known as EPOC (excess post-exercise oxygen consumption)

• but scientists realised that we take in more O2 after exercising than is needed to oxidise lactic acid– so must be using this O2 for other things

EPOC- USE FOR EXCESS O2

• oxidise lactate into pyruvate

• convert pyruvate into glucose in a process called gluconeogenesis that happens in liver (glucose used to replenish glycogen stores)

• restore ATP and phosphocreatine levels in muscle fibres

• reoxygenate myoglobin in muscles

• maintain increased rate of chemical reactions as a result of increased temps and adrenalin production

• supply heart w/ the extra O2 it needs to maintain elevated heart rate

• supply diaphragm and rib muscles w/ extra O2 needed to maintain rapid breathing rate

ANAEROBIC RESPIRATION- DIAGRAM