how does hemoglobin carry O2 in the blood?

Answer 1

Since this is not my area of expertise, I searched Google under the key words "hemoglobin oxygen" to get these possible sources:

http://en.wikipedia.org/wiki/Hemoglobin
http://www2.austin.cc.tx.us/~emeyerth/hemoglob.htm
http://www.ventworld.com/resources/oxydisso/dissoc.html
http://people.eku.edu/ritchisong/RITCHISO//301notes6.htm
http://www.sciencedaily.com/releases/2007/11/071106102646.htm
http://express.howstuffworks.com/web-quest-exercise.htm

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.

I hope this helps. Thanks for asking.