Hemoglobin & Myoglobin

That is going to start the conformational change the

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: 5 degree between deoxy and oxyhemoglobin - the c entral cavity of deoxy. a little hold and then when oxygen binds you c an no longer see the hole-- there is a change of conformation between the alpha beta axis Size of the central cavity changes on binding oxygen 2/8 and 2/11/13 MCB 2000 Lecture 6 Conformational Change: Oxygenated vs. Deoxygenated Hemoglobin https://iwasa.hms.harvard.edu/project_pages/hemoglobin/hemoglobin.html 2/8 and 2/11/13 MCB 2000 Lecture 6 !"#$%&$'()*G7$80*Z&&$01"2(5*<"73:($2* [732351"2(01(50*$9*42$1"()0*8(17*3&&$01"2(5* '"73:($2* \/31"2)32-*012/51/2"* [$$4"231(:(1-*&"3;0*1$*573)%"*()*5$)9$2#31($)* G(%#$(;3&*'();()%*5/2:"*$2*]()"1(50* * Difference between hemoglobin and mygolbin besides the stucture? - because hemogolbin has 4 subunits and each of them can bind to heme - when oxygen binds to the fi rst heme in one of the subunits that is going to start the conformational change - the binding to oxgyen to one subunit will effect the binding of the next subunit becuase of the change in conformation - this will be translated across the entrire molecule. becuase mygolbin doesn't have any partners will not show this behavior - this is called cooperativity the subunits of hemogolbin are interactive and when oxgyen binds they show cooperativity - communication between subunits. Q uaternary - leads to cooperativity - which leads to sigmoidal curve 2/8 and 2/11/13 MCB 2000 Lecture 6 Compare the oxygen binding curves for hemoglobin and myoglobin Note the different shapes of each curve: Mb is hyperbolic Hb is sigmoidal (Sshaped) Degree of staturation with myoglobin and hemoglobin - 0.5 Y - straight line and then drop line down - this s hows the releavent something - lower partial pressure - the S shape for hemoglobin becuase of c opperavity - myoglobin will never give you an Sshaped curve) because lackcopperativiety because only has one subunit need mult. subunit to have c orperativity. 2/8 and 2/11/13 MCB 2000 Lecture 6 Deoxy hemoglobin - the T state - less advice state (tight) The R state - exsist with oxygenated hemoglobin - more active and Relaxed state (R) Sigmoid shape of oxygen saturation curve indicates cooperativity between subunits in binding oxygen 2/8 and 2/11/13 Binding of oxygen to one subunit disrupts some noncovalent interactions while forming new ones. Alteration in conformation makes it easier for oxygen to bind to other subunits. MCB 2000 Lecture 6 !$8*;$"0*17"*$F-%")*;(00$5(31($)*5/2:"* 2"&31"*1$*;"&(:"2-*$9*$F-%")*()*17"*'$;-V* Hemoglobin - trasnport oxygen and myogolbin - store oxygen - rely only on myoglobin - our tissue would not get enough oxygen - partial pressure in the lungs - myoglobin has only released 7% of its oxygen - not good when taking about aerobic respiration where hemoglobin will release 66% of its oxygen at the s ame partial pressure - myo...
View Full Document

This note was uploaded on 09/17/2013 for the course MCB 2610 / 200 taught by Professor Feldman during the Fall '12 term at UConn.

Ask a homework question - tutors are online