Biology B4 - Excersise

why do we not need a lot of energy when we are relaxing

because we aren't moving

during excersise why does the body need energy

for muscle contraction, the body has to react to the increased demand for energy

why does aerobic respiration increase

because the body needs more energy

why does the body need more energy

because the body cells require more oxygen

how does the body provide extra oxygen for the cells?

both the breathing rate and breathing volume increase (breathe more frequently, take deeper breaths)

what does doing this do?

gets more oxygen into the bloodstream

why does the heart rate also increase during excersise

to pump this oxygenated blood around the body

Why does anaerobic respiration occur in the muscles during excersise?

if not enough oxygen is getting to our muscles

because the oxidation of glucose is incomplete what does this lead to

the build up of the chemical lactic acid

what happens during long periods of vigorous activity

the lactic acid causes the muscles to become fatigued

what does this cause

the muscles to stop contracting effciently

what do the muscles have to do at this point

remove the lactic acid

what condition does this create

oxygen debt

where is the lactic acid transported

-out of the muscles into the blood

-then taken to the liver and converted back into glucose in a series of chemical reactions

does removing the lactic acid from the cells require oxygen

yes

What is oxygen debt?

The amount of extra oxygen the body needs after exercise to deal with the accumulated lactic acid and remove it from the cell

that is why people continue breathing rapidly for some time after finishing excersise.