Module 5

Question 1

what is a ligand ?

Answer 1

anything that’s being bound by a protein

Question 2

what is the specific site that ligand bind to called

Answer 2

the binding site

Question 3

what are the ligands of hemoglobin?

Answer 3

oxygen, 2,3 bisphosphoglycerate

Question 4

what might the binding of a ligand change?

Answer 4

it might cause a conformational change

Question 5

what is induced fit?

Answer 5

binding of a ligand changing the conformational change of a protein

Question 6

what does myoglobin do ?

Answer 6

facilitates oxygen storage in peripheral tissue

Question 7

what does hemoglobin do? and where is it found?

Answer 7

transports oxygen from lungs to the periphery. found in red blood cells

Question 8

how many oxygen are attached to hemoglobin?

Answer 8

4

Question 9

how many coordinating interactions does Fe2+ seek

Answer 9

6

Question 10

what does the distal histidine in a heme group do

Answer 10

provides a stabilization interaction for bound O2

Question 11

what is myoglobin with a single sub unit ?

Answer 11

a tertiary structure

Question 12

what is hemoglobin with 4 sub units

Answer 12

quaternary structure

Question 13

how many heme groups does myoglobin have? how many oxygen molecules can bind to it ?

Answer 13

one heme group - one oxygen molecule

Question 14

how many heme groups does hemoglobin have? how many oxygen molecules can bind to it ?

Answer 14

four heme groups - four oxygen molecules

Question 15

what does the binding of oxygen by hemoglobin display? what does this indicate?

Answer 15

it displays sigmoidal behaviour on a graph and it indicates coopertivity of oxygen binding

Question 16

which has a higher affinity for oxygen? hemoglobin or myoglobin?

Answer 16

myoglobin

Question 17

what does myoglobins high affinity for oxygen indicate?

Answer 17

it is normally saturated with oxygen everywhere in the body

Question 18

what is an allosteric protein?

Answer 18

a protein that can adopt different conformations

Question 19

what kind of protein is hemoglobin?

Answer 19

allosteric protein

Question 20

what is the T state of hemoglobin?

Answer 20

the inactive form. no oxygen bound and low affinity for oxygen

Question 21

what is the R state of hemoglobin?

Answer 21

the active form. as oxygen binds to it it goes into the R state. high affinity for oxygen

Question 22

what is a modulator?

Answer 22

small molecules that can bind to an allosteric protein to help shift equilibrium

Question 23

what do allosteric activators stabilize?

Answer 23

the R state

Question 24

what do allosteric inhibitors stabilize?

Answer 24

the T state

Question 25

what is it called when a modulator and the ligand are the same?

Answer 25

a homotropic interactions

Question 26

what is it called when a modulator is different from the normal ligand

Answer 26

a heterotrophic interaction

Question 27

what is O2 to hemoglobin?

Answer 27

a homotropic allosteric activator

Question 28

what is 2,3 BPG to hemoglobin?

Answer 28

an heterotrophic allosteric inhibitor

Question 29

what is the deoxyhemoglobin pocket a very attractive binding site for

Answer 29

2,3 BPG

Question 30

does fetal hemoglobin have a Higher affinity for oxygen?

Answer 30

yes

Question 31

how can adaptation to high altitude occur?

Answer 31

increased production of 2,3 BPG

Question 32

what is the Bohr effect

Answer 32

describes the pH dependence of hemoglobins affinity for O2

Question 33

what does a decrease in pH do to hemoglobin?

Answer 33

makes hemoglobin have a lower affinity for O2

Question 34

what does increased 2,3 BPG do to hemoglobin?

Answer 34

decreases hemoglobins affinity for O2

Question 35

what does a greater production of CO2 do?

Answer 35

it lowers the pH which lowers hemoglobins oxygen affinity to promote releasing O2 to active tissues

Question 36

what do invertebrates use to carry oxygen?

Answer 36

hemocyanin