14. Erythrocytes, haemoglobin and haemoglobin genes Flashcards
Why are RBC that specific shape?
Biconcave shape provides a large surface area for the uptake and release of oxygen and carbon dioxide
What is the function of erythrocyte?
O2 transport depends on Hb in erythrocytes
What does adult Hb contain?
2 alpha and 2 beta chains plus haem groups
What is conformation?
The final folded shape of a protein
What is required to achieve conformation?
Molecular chaperones
What do the hydrophobic forces help to do?
Helps fold proteins into compact conformations
What are the three types of bonding that influence folding?
Hydrogen bond
Ionic bond
van der Waals inteactions
What are the features of the alpha helix structure?
Right- handed corkscrew
Maintained by H bonds between peptide bonds
Some chains destabilise alpha helix
What are the features of the beta sheet?
Stretched out structure
H bonds between C-O and NH groups
Parallel or anti parallel
What does HbF mean?
Fetal haemoglobin
What does HbA mean?
Adult haemoglobin
What does HbS mean?
Sickle cell haemoglobin
What is the reason for globin chain switching?
The composition changes as the conc of oxygen in the environment changes
How does O2 get transferred across the placenta from maternal circulation to fetus?
The affinity of Hb for O2 in the fetal red cells has to be greater than affinity of Hb in maternal cells do this by using diferent Hb genes at different genes at different times
Describe the point mutation in Hb?
Single base change changes an acidic, polar residue to a hydrophobic one
