BIBC 100 Handout 5

BIBC 100 Handout 5 - BIBC 100 Structural Biochemistry...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: BIBC 100 Structural Biochemistry Handout 5 (Lecture 13) Mimi Nguyen OH Fri 10:30–11:30am 1st Floor S&E Hb Oxygen Binding • Hb goes from low O2 affinity ______________ to high O2 affinity ______________ as more O2 is bound o • • As O2 is released from Hb, the binding affinity ______________ and more O2 is easily released by the other subunits Bohr Effect: O2 Association Curve o The O2 binding curve shifts to the _____________ as pH decreases Hb has an inverse affinity to O2 and H+ • • When [O2] ______, Hb binds O2 and releases H+ When [O2] ______, Hb binds H+ and releases O2 This ion-pair forms, stabilizing the _______________ ______________ O2 affinity and more O2 released into the As pH decreases in Hb, HisHC3 ______________________ with AspFG1 • o In the tissues ______ pH and ______ [CO2] tissues o In the capillaries (lungs) ______ pH and ______ [CO2] • 2,3 Bisphosphoglycerate (BPG) Lehn Fig. 5.17 o o o • Binding occurs in the __________________ BPG will _________________ the affinity for O2 by stabilizing the _________________ At higher altitude [BPG] increases. Why? ______________ O2 affinity and more O2 is bound to Hb Sickle Cell Anemia o o o o A single amino acid substitution: ________ ________ (E6V) HbS Fibers (B & T Fig. 3.14) The hydrophobic residue fits perfectly into hydrophobic pocket Increased resistance to malaria Sickle forms in deoxy T-state at capillaries, making it harder to transport O2 • Carbon Monoxide Poisoning o o o Lehn Box 5-1 CO is a colorless, odorless gas that binds to Hb with a greater affinity than O2 Anemia vs. CO poisoning Anemic Hb are more ready to release O2 because CO has a higher affinity than O2 to Hb, so anemic Hb will still deliver O2 whereas CO-Hb will not dissociate as easily and therefore no O2 transport will occur. 1 ...
View Full Document

This note was uploaded on 01/02/2010 for the course BIBC BIBC 100 taught by Professor Buehler during the Fall '09 term at UCSD.

Ask a homework question - tutors are online