Chapter 15 Study Questions (Pt. 2)

Question 1

what does Hb stand for?

Answer 1

hemoglobin

Question 2

what is hemoglobin?

Answer 2

a protein in red blood cells that carries oxygen from the lungs to the body’s tissues

Question 3

what is Hb composed of?

Answer 3

4 globin proteins

4 heme chemical groups

Question 4

what is the function of the heme chemical group?

Answer 4

heme holds iron, iron captures O2

Question 5

what is the function of the globin protein?

Answer 5

prevent Fe+2 from further oxidation to Fe+3

Question 6

how do globin proteins prevent Fe+2 from further oxidation to Fe+3?

Answer 6

Fe+2 and +3 can bind O2, but Fe+3 isn’t reversible.

to make sure that the reaction stays reversible, globin protein prevents Fe+2 from losing another electron and becoming Fe+3.

Question 7

what is cooperative binding ?

Answer 7

once one subunit binds, the rest do too –> peer pressure

Question 8

what is cooperative binding of O2 to hemoglobin? (2)

Answer 8

• Hb changes from tense to lax conformation
• enhances O2 binding at all 4 hemoglobin subunits

Question 9

tense state of globin = binds or doesn’t bind O2?

Answer 9

doesn’t bind O2.

Question 10

relaxed state of globin = binds or doesn’t bind O2?

Answer 10

binds

Question 11

what are the two states globin can be in?

Answer 11

relaxed and tense

Question 12

which state do the four globin proteins want to be in? why?

Answer 12

all tense or all relaxed.

a mix isn’t easy to maintain / stable

Question 13

how does the relaxed state of hemoglobin promote O2 binding?

Answer 13

Fe+2 within the heme group is more accessible to O2 in relaxed state.

Question 14

why do we call is hemoblogin?

Answer 14

cause it’s made up of heme groups and globin proteins! not a joke.

Question 15

when old RBCs are recycled and hemoglobin is broken down, what happens to the globin protein?

Answer 15

recycled to reuse the amino acids

Question 16

when old RBCs are recycled and hemoglobin is broken down, what happens to the heme chemical group?

Answer 16

some is reused, rest is catabolized to bilirubin. body wants to get rid of bilirubin.

Question 17

when old RBCs are recycled and hemoglobin is broken down, what happens to the globin protein and heme chemical group?

Answer 17

globin: recycled to reuse the amino acids

heme: some is reused, rest is catabolized to bilirubin. body wants to get rid of bilirubin.

Question 18

the body wants to get rid of bilirubin. who does it?

Answer 18

liver

Question 19

what is the potential negative impact of infant hyperbilirubinemia?

Answer 19

permanent brain damage

Question 20

how is infant hyperbilirubinemia treated in newborns?

Answer 20

phototherapy forms a bilirubin isomer that is more water soluble and therefore more easily removed by the liver

Question 21

in treating infant hyperbilirubinemia, phototherapy forms a bilirubin isomer that is more water soluble. why is the new form more water soluble?

Answer 21

hydrophilic group is closer to the outside and more accessible than in the original conformation

Question 22

what is bilirubin? how is it removed from the body?

Answer 22

a waste product of red blood cell breakdown. it is removed from the body in bile.

Question 23

what is infant hyperbilirubinemia? what causes it?

Answer 23

a condition in which a newborn’s blood contains too much bilirubin.

normally, the liver removes bilirubin. when it doesn’t bilirubin levels in the blood may rise.