Class Notes (809,909)
United States (313,931)
Boston College (3,505)
Biology (470)
BIOL 4350 (29)
Lecture 35

BIOL 4350 Lecture 35: Lecture 35

3 Pages
Unlock Document

Boston College
BIOL 4350
Rebecca Dunn

APRIL 19 PPT23 (1-10) LECTURE 35 Skipped what we were going to talk about Last test is Monday, May 1 Hemoglobin - Oxygen transport o Not sufficiently soluble in water o There is dissolved oxygen o Not enough for tissues and needs - Globins o Oxygen binding proteins o Not a single amino acid side chain capable of binding to oxygen o Need a protein with a bound heme group ▪ Some use copper o Many oxygens use a globin protein to bind and transfer it in the blood o Globins are used to study about ligand binding because oxygen acts as a ligand o Strictly alpha-helical* ▪ Depicted as cylinders o Myoglobin ▪ Storage protein ▪ Monomeric ▪ Stored in muscle ▪ Structure • Oxygen bound to the globins requires protein breathing* • There is not enough room within protein structure for oxygen to be diffused • You have to infer there is a conformational change in order for oxygen to bind o Matters because: anything is possible and there is always dynamic movement ▪ Binds to oxygen in a manner that is dependent on the concentration of oxygen • Depicted as partial oxygen pressure • Measured experimentally • Binding is dependent on the pressure ▪ Saturation • Amount that is bound to oxygen • Increase and then plateau at a partial pressure • Hemoglobin binds at a higher partial pressure than myoglobin o More of a sigmoidal shape • If myoglobin is a storage protein o Hemoglobin will be maximally bound when it leaves the lungs, when it gets into peripheral tissues the hemoglobin saturation will go down and the myoglobin will go up • P50 for hemoglobin is 26 torr o Quantitative Description [PL] k ▪ Not going to be tested on K = = a ▪ Remember* a • Kaassociation equilibrium complex [P]×[L] k • Higher the number, the stronger the interaction d ▪ 1/Ka=Kd APRIL 19 PPT23 (1-10) LECTURE 35 • measure of the affinity between 2 things • Kd gives you the concentration at which the ligand is 50% bound • If you know the Kd, you know the concentration at which it is half bound o Will tell you the relevant concentration for that thing o Hemoglobin ▪ Transfer oxygen from lungs to peripheral proteins ▪ Transfer protein • Affinity for oxygen needs to vary over a bigger range • You need for it to bind well to oxygen well and also let it go well • Unlike myoglobin, hemoglobin can release the oxygen when it gets to where it is going
More Less

Related notes for BIOL 4350

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.