protein and hemoglobin part 2

Question 1

what do hemoglobin and myglobin have in common

Answer 1

8 alpha helices labeled A-H

Question 2

Mb is similar to what subunit

Answer 2

the Beta

Question 3

what does the Y02 curve for myoblin and hemoglobin

Answer 3

myoglobin = hyperbola= no cooperativity
Heme= sigmoidal = cooperativity

Question 4

binding of one substrate molecule to the active site of one subinit locks…

Answer 4

all subunits in active conformation

Question 5

what is allostery

Answer 5

other site

Question 6

binding at one site affects what

Answer 6

binding at others

Question 7

wht does allosterism require

Answer 7

protein wth more than one subinit

Question 8

what does S curve indicate

Answer 8

cooperativity = allosterism

Question 9

what is homotropic allosteric interaction

Answer 9

effector and ligand are regulated by the effector are same molecule (eg. O2 and Hb)

Question 10

what is heterotropic allosteric interaction

Answer 10

effector and liganrd are different molecules

Question 11

what is an activator

Answer 11

shifts the equilibrium toward R state= stabilizes R state= positive allosteric interaction

Question 12

what is an inhibitor=

Answer 12

= shifts the equlibrium toward T state= negative allosteric interaction

Question 13

what does R state mean

Answer 13

relaxed and it has high affinity

Question 14

what does T state mean

Answer 14

tense- low affinity

Question 15

does Mb have T and R states

Answer 15

no

Question 16

what has low affinity in Hb

Answer 16

BPG. H+ and CO2

Question 17

what has high or relaxed affinity

Answer 17

O2 bc its a homotropic effector

Question 18

what is the bohn effect

Answer 18

increased temperature = release of o2 from Hb
- increase CO2, decreasing pH or increasing temp causes the release of O2 from HB decreasing affinity for O2

Question 19

bohr effect
high temp =

Answer 19

high temp = low Hb affinity for

Question 20

where on T state do Bohr protons bind

Answer 20

N terminal anino gps are responsible for 20-30%

Question 21

H bonds and ion pairs are present in which state

Answer 21

T state

Question 22

His 146B does what

Answer 22

accounts for about 40% of the bohn effect

Question 23

what does the Tto R transition change

Answer 23

• pka of these groups ( lowering pka ) causing them to release coordinated H

Question 24

can a surrounding protein structure change PKA

Answer 24

yes

Question 25

H+ (bohr protons ) are releasd when

Answer 25

Hb binds to O2