Structure of Haemoglobin

Question 1

Properties of RBC

Answer 1

• Easily deformable structure
• Able to squeeze through small capillaries
• Sustain high-pressure environment of heart
• Sustains itself despite trauma of the heart valves

Question 2

Function of haemoglobin

Answer 2

Picks up, carries and gives up oxygen

Question 3

Haemoglobin consists of?

Answer 3

• 4 globin chains
• Heme moiety lies between globin chains
• Heme moiety is made of porphyrin with a central iron component

Question 4

Heme moiety composition

Answer 4

Porphyrin with a central iron component

Question 5

Haemoglobin can carry how many oxygen molecules?

Answer 5

4 oxygen molecules

Question 6

How do globin chain change over time depending on the stage of development?

Answer 6

Embryos trying to hold onto Oxygen so the globin chains in embryonic and foetal haemoglobin have greater affinity for oxygen.

• When blood starts being made in liver, epsilon chain switches to alpha
• Gamma chain switches to beta shortly after

Question 7

Biconcave disc of RBC increases?

Answer 7

Increases its surface area

Question 8

RBC has a nucleus and mitochondria

Answer 8

False, it doesn’t have nucleus or mitochondria

Question 9

How does RBC get its energy?

Answer 9

Under anaerobic conditions.

1) Six-carbon molecule is split into two three-carbon molecules
2) Energy from molecules is extracted and stored in the form of ATP and NADH (pyruvate kinase is the final enzyme in this pathway)

Question 10

RBC undergoes ________ as a by-product of oxygen transport.

Answer 10

Oxidative stress

Question 11

Oxygen transport process produces?

Answer 11

Reactive oxygen species

Question 12

Function of reactive oxygen species

Answer 12

ROS converts important ferrous molecule (Hb) to ferric

Question 13

Ferric

Answer 13

Hb cannot carry oxygen

Question 14

ROS damages _____ and this causes?

Answer 14

Damages lipid membranes, shortening the life span of red cells

Question 15

Function of glutathione?

Answer 15

Glutathione scavenges reactive oxygen species

Question 16

Oxidized form of glutathione is regenerated by?

Answer 16

Glutathione reductase

Question 17

Process of oxygen transport needs?

Answer 17

NADPH

Question 18

NADPH is generated by?

Answer 18

Hexose monophosphate shunt

Question 19

Hexose monophosphate shunt uses _____ for oxygen transport

Answer 19

G6PD

Question 20

Absence of G6PD can cause?

Answer 20

Can cause inherited form of anaemia

Question 21

RBCs have _______ which provide shape and flexibility

Answer 21

Membrane and cytoplasmic skeleton

Question 22

Ankyrin anchors?

Answer 22

Anchors Band 3 to the cytoskeleton

Question 23

What is Band 3?

Answer 23

Transmembrane complex

Question 24

Cytoskeleton in RBC is a network of?

Answer 24

Network of alpha and beta spectrin

Question 25

What attaches to Band 3?

Answer 25

Sugar i.e. glycoproteins or blood group antigens

Question 26

Loss of horizontal interactions in RBC, RBCs develop into a?

Answer 26

Spherocyte

Question 27

Loss of vertical interactions (i.e. cytoskeleton), RBC develops into?

Answer 27

Develops into an elliptocyte (cigar shape)