Coursework urgent help

What do you need to do for it? Normally you'd have to do some sort of experiment, but every school is different. If all you have to do is write about it, then use class notes or a revision guide. If you don't have those, then I guess the internet is a helpful tool.

Aerobic respiration is where oxygen and glucose are transported by blood and diffuse from capillaries into all your cells. The cells convert this into energy (never say that they create or produce energy!!) and release a waste product of carbon dioxide, which diffuses back into capillaries and gets transported back to the lungs where it is exhaled.
Aerobic exercise is when you exercise but don't go into anaerobic respiration (which is respiration with the minimal use of oxygen to produce a waste product of lactic acid).

That's pretty much all there is on the subject at GCSE, apart from some stuff on oxygen debt (now called EPOC), but you can research that.