Structure of Haemoglobin Flashcards
Properties of RBC
- Easily deformable structure
- Able to squeeze through small capillaries
- Sustain high-pressure environment of heart
- Sustains itself despite trauma of the heart valves
Function of haemoglobin
Picks up, carries and gives up oxygen
Haemoglobin consists of?
- 4 globin chains
- Heme moiety lies between globin chains
- Heme moiety is made of porphyrin with a central iron component
Heme moiety composition
Porphyrin with a central iron component
Haemoglobin can carry how many oxygen molecules?
4 oxygen molecules
How do globin chain change over time depending on the stage of development?
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
Biconcave disc of RBC increases?
Increases its surface area
RBC has a nucleus and mitochondria
False, it doesn’t have nucleus or mitochondria
How does RBC get its energy?
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)
RBC undergoes ________ as a by-product of oxygen transport.
Oxidative stress
Oxygen transport process produces?
Reactive oxygen species
Function of reactive oxygen species
ROS converts important ferrous molecule (Hb) to ferric
Ferric
Hb cannot carry oxygen
ROS damages _____ and this causes?
Damages lipid membranes, shortening the life span of red cells
Function of glutathione?
Glutathione scavenges reactive oxygen species
Oxidized form of glutathione is regenerated by?
Glutathione reductase
Process of oxygen transport needs?
NADPH
NADPH is generated by?
Hexose monophosphate shunt
Hexose monophosphate shunt uses _____ for oxygen transport
G6PD
Absence of G6PD can cause?
Can cause inherited form of anaemia
RBCs have _______ which provide shape and flexibility
Membrane and cytoplasmic skeleton
Ankyrin anchors?
Anchors Band 3 to the cytoskeleton
What is Band 3?
Transmembrane complex
Cytoskeleton in RBC is a network of?
Network of alpha and beta spectrin
What attaches to Band 3?
Sugar i.e. glycoproteins or blood group antigens
Loss of horizontal interactions in RBC, RBCs develop into a?
Spherocyte
Loss of vertical interactions (i.e. cytoskeleton), RBC develops into?
Develops into an elliptocyte (cigar shape)
