oxygen transporter

Question 1

monomeric helical protein that contains hem

Answer 1

Myoglobin

Question 2

where does myoglobin trasnport oxygen?

Answer 2

muscle

Question 3

bright red

Answer 3

oxygenated

Question 4

brownish

Answer 4

oxidized heme

Question 5

blue

Answer 5

deoxygenated

Question 6

the two roles of histidine in both myoglobin and hemo globin

Answer 6

• one forms a ligand to the iron that moves on oxygenation

- the other histidine reduces CO binding

Question 7

There is only a minor change in the structure of myoglobin upon ______________

Answer 7

deoxygenation

Question 8

The two conformations of hemoglobin

Answer 8

• T form

- R form

Question 9

T conformation

Answer 9

binds to oxygen poorly

Question 10

R conformation

Answer 10

binds oxygen with higher affinity

Question 11

negative allosteric effectors

Answer 11

CO2, H+ and BPG

Question 12

CO2, H+ and BPG bind to sites different from _____ and _______

Answer 12

oxygen and carbon monoxide

Question 13

Actively metabolizing tissue produces ____ and _____, thus promoting _____ release from hemoglobin

Answer 13

Actively metabolizing tissue produces CO2 and H+, thus promoting oxygen release from hemoglobin

Question 14

BPG binds to a pocket formed by

Answer 14

the two beta chains

Question 15

Fetal hemoglobin is a ______ and binds ______ less well. It is the _______ ___ of hemoglobin at birth

Answer 15

Fetal hemoglobin is a alpha2gamma2 and binds to BPG less well. It is the dominant form of hemoglobin at birth

Question 16

has a substitution in the Beta subunit

Answer 16

HbS

Question 17

In sickle cell, there is more sickling under ____ oxygen conditions

Answer 17

low

Question 18

Mechanism of HbS involves a ______ pocket that forms under ______ oxygen conditions which is different pocket than the one bound by _____

Answer 18

Mechanism of HbS involves a hydrophobic pocket that forms under low oxygen conditions which is different pocket than the one bound by BPG

Question 19

The substitution on HbS adds a ______ surface knob that can fit into the _____ hole formed by __________ hemoglobin

Answer 19

The substitution on HbS adds a hydrophobic surface knob that can fit into the hydrophobic hole formed by deoxygenated hemoglobin

Question 20

Methemoglobin carries

Answer 20

Fe3+

Question 21

cannot carry oxygen

Answer 21

Methemoglobin

Question 22

True or false: Methemoglobin is only inherited

Answer 22

false, can be in-born (mutations near the heme-binding pocket that promote iron oxidation or acquired by ingestion of large amounts of oxidizing agents

Question 23

example of a reducing agents that can reduce iron to the active Fe2+

Answer 23

Vitamin C

Question 24

two thalassemias

Answer 24

• alpha thalassemia for lack of alpha chains

Beta Thalassemia for lack of Beta chains

Question 25

Splicing error dx

Answer 25

thalassemias

Question 26

where does oxygen binds to the hemoglobin

Answer 26

heme

Question 27

where does carbon dioxide bind in the hemoglobin

Answer 27

the N-terminal alpha-amino group (alpha subunits)

Question 28

where does carbon monoxide bind in the hemoglobin?

Answer 28

heme

Question 29

where does BPG bind in hemoglobin

Answer 29

pocket formed by the Beta subunits

Question 30

where does the Hydrogen bind in the hemoglobin

Answer 30

a histide and the N-terminal Alpha aa