Should i apply for fall 2010? confused

i need 2 more science classes: microbiology and chemistry (a mixture of organic chem, biochemistry, ect.). all nursing programs want me to finish these classes by the time I enter their school. i'm planning to take chem next semester and microbiology in the summer. the problem is i don't know if i will get in these classes for sure. should i just apply right now (i just want to get my nursing degree so badly!) or wait until i finish with both classes then apply? help.