where do hydrogen ion(Bohr effect) and 2,3 BPG bind to? porphyrin or just the globin chains?
The protein chains. BPG binds to deoxy-Hb so favours deoxygenation. A bit unusual in that it binds just one molecule BPG per Hb tetramer (in the cavity between the beta chains).
I believe the Bohr protons bind in lots of places but I am not up to date.
This site is not for getting basic textbook information, more for conceptual difficulties and puzzles when you read the books or try to answer the problems. There is lots on the web e.g. http://www.biochem.arizona.edu/classes/bioc460/spring/460web/lectures/LEC8-9_MbHb_08-ppt.pdf
and lots of others.
Separate names with a comma.