L8

Question 1

What 2 proteins are responsible for O2 storage and transport?

Answer 1

hemoglobin and myoglobin

Question 2

what is hemoglobin?

Answer 2

hemoglobin is the red blood pigment exclusively present in erythrocytes(RBC)

Question 3

List all 4 types of hemoglobin that are synthesized in the human body throughout its life span and explain when they are present . .

Answer 3

Hbε(epsilon) :Present in embryonic life ( Hb Gower-1). Composed of 2 - ζ(zeta) and 2 - ε chains.

HbF:Fetal stage (Second trimester till birth). Composed of 2 – α and 2 – γ chains.

Hb A1:Major normal adult Hb (Starts with birth and reaches completion by around 6 months). Composed of 2 - α and 2 - β chains.(gamma gene is almost off)

Hb A2:Minor normal adult Hb Composed of 2 - α and 2 - δ (delta) chains.

Question 4

what is the normal adult blood content?

Answer 4

Hb A1 - 97%
Hb A2 - 2%
Hb F - 1%

Question 5

what is the function of hemoglobin of hemoglobin and myoglobin ?

Answer 5

hemoglobin transports blood

helps with transport co2 from tissues to lungs

acts as buffer

while myoglobin stores it . if there is not enough hemoglobin then hemoglobin anemia will occur

Question 6

how many oxygens can hemoglobin and myoglobin bind too , how many chains do they have ?

Answer 6

hemoglobin can hold 4 oxygens while myoglobin can only hold 1

Question 7

all hemoglobin are hetro-tetramere

Answer 7

.

Question 8

describe the structure of hemoglobin A1

Answer 8

IT IS A CONJUGATED PROTEIN . HEME BEING THE PROSTHETIC GROUP

 Globin (96% of Hb)

4 polypeptide chains of two different primary structures (2 - α and 2 - β chains)
Each chain has one heme group attached to it.

Question 9

What is the heme inside the ?

Answer 9

complex of iron Fe++ ferrous and protoporphyin (has 4 pyrrole rings )

Question 10

what are the 6 bonds Fe++ forms ?

Answer 10

4 with the N of porphyrin.
On one side of the plane with a.a histidine (proximal) of the globin.
The other side with O2.
1 Hb can bind and transport 4 O2

Question 11

describe the structure of a myoglobin.

Answer 11

conjugated protein with prosthetuic group being skeletal muscles and cardiac muscles

consists of one pollypeptide chain (monomeric)

has 1 molecule of heme attached

Question 12

In the muscles:
Mb acts as an O2 storage protein in muscles.
O2 is taken up and stored by Mb.
Mb has high affinity for O2 than Hb.

Answer 12

.

Question 13

the ODC for myoglobin is?

Answer 13

hyperbolic . it shows high affinity for oxygen (uptight)

Question 14

the ODC for hemoglobin is ?

Answer 14

sigmoidal. has comparatively low affinity for oxygen. this also indicates that binding of O2 to Hb is cooperstive . binding of O2 to one heme increases binding affinity of O2 to other hemes of the same Hb molecule

Question 15

there is communication among subunits in the hemoglobin function

Answer 15

..

Question 16

what major forms are co2 present in the body.

Answer 16

Dissolved CO2
Bicarbonate (HCO3-)
Carbaminohemoglobin (Carbon dioxide linked to hemoglobin)

Question 17

explain co-operative bining.

Answer 17

binding of O2 to one heme increases binding affinity of O2 to other gmes of the same Hb molecule . thgis occurs because there is communication among subunits in the hemoglobin function