Haemoglobin & Oxygen Transport: Basics (Ms.D)

Question 1

What are HAEMOGLOBINS?

Answer 1

-GLOBULAR Protein molecules with QUATERNARY structure
-Evolved for efficiency of loading
-4 POLYPEPTIDE chains linked together
–>Each of which are associated with a HAEM group containing Fe(II) (Ferrous) which can combine with an O2 molecule
(4 in total)

Question 2

What is OXYGEN LOADING?

Answer 2

-Process by which HAEMOGLOBIN bind with O2 is called LOADING or ASSOCIATING
-In humans it takes place in the LUNGS

Question 3

What is OXYGEN UNLOADING?

Answer 3

-Process by which HAEMOGLOBIN releases its O2 is called UNLOADING or DISSOCIATING
-In humans this takes place in the TISSUES

Question 4

What does HIGH AFFINITY mean?

Answer 4

-The O2 will BIND onto the HAEMOGLOBINS EASIER
-But RELEASES LESS EASILY

Question 5

What does LOW AFFINITY mean?

Answer 5

-More difficult for the O2 to BIND onto the HAEMOGLOBINS
-But RELEASES EASIER

Question 6

What does POSITIVE CO-OPERATIVITY mean?

Answer 6

-Binding of FIRST molecule makes binding of SECOND EASIER and so on
-So GRAD. of the CURVE STEEPENS

Question 7

What is meant by PARTIAL PRESSURE?

Answer 7

-Measure of CONC. of a GAS in a MIXTURE of gases
-By CALCULATING PRESSURE it contributed to OVERALL PRESSURE

Question 8

What are the CONDITIONS that EFFECT the AFFINITY of OXYGEN?

Answer 8

-Partial Pressure of O2 (pO2)
-Haemoglobin Saturation
-Partial Pressure of CO2 (pCO2)

Question 9

What are the ADAPTATIONS of an RBC?

Answer 9

-Biconcave Shape
-Large SA
-Flexible to move around
-No nucleus to carry more O2

Question 10

What happens to the OXYGEN AFFINITY of HAEMOBLOGIN as pCO2 INCREASES?

Answer 10

DECREASES

Question 11

Where in the BODY is the pO2 HIGHEST?

Answer 11

Lungs

Question 12

How does INCREASED RESPIRATION affect BLOOD pH?

Answer 12

Increase
-Less CO2 levels in blood so more alkaline

Question 13

How does the SATURATION of HAEMOBLOGIN affect its AFFINITY for O2?

Answer 13

Increased SATURATION = Increased AFFINITY for O2

Question 14

What direction the the DISSOCATION CURVE shift during the BOHR EFFECT?

Answer 14

Right

Question 15

What is the main DIFFERENCE between FOETAL HAEMOGLOBIN and ADULT HAEMOGLOBIN?

Answer 15

-FOETAL HAEMOGLOBIN has a HIGHER AFFINITY for O2
-Due to presence of 2 GAMMA CHAINS

Question 16

How does the SA of an ORGANISM AFFECT the AFFINITY for O2?

Answer 16

-Less SA = LESS AFFINITY
-Curve is SHIFTED to the RIGHT

Question 17

Describe the SIMPLE STRUCTURE of HGB

Answer 17

-2α SUBUNITS
-2β SUBUNITS
-4 HAEM GROUPS