Blood and immune L2 Flashcards
(38 cards)
Distinctive features of Red blood cells
- biconcave disc shape
- No nuclei or organelles
- Filled with haemoglobin (red protein) which binds to oxygen
- 6-8 micrometers.
size of an Angstrom in nm
1 Angstrom=0.1nm or 10,000 Angstrom = 1000nm = 1 micron
How do red blood cells orientate/come about?
Orientate from myeliod stem cells in bone marrow which goes in the following steps:
Stems cells differentiate into proerythoblasts, and then early erythroblasts, late erythroblast (hamoglobin accumulation), normal blast, reticulocytes looses nucleus staying in bone marrow for serval days before entering circulation, after time in circulation mature and become erythrocyte. This is called Erythropeosis.
Time RBC spend in the blood system
120 days.
What happens to the RBC after 120 days?
Destroyed by spleen, liver and bone marrow. Destruction by macrophages which engulfs RBC and breaks down into haemoglobin, further broken down into globin and heme, global into amino acids and heme= Bilirubin and iron
RBC contain what on their surface?
RBC contain glycolipids in the plasma membrane that act as antigens that account for the different various types of blood groups such as ABO .
Proteins within blood includes…
Lysozome, haemoglobin, Serum Albumin, Immunoglobulin
Lysozome structure
129 amino acid chain, contains both alpha helical and beta pleated sheets.
Hemoglobin structure
4 chains consisting of 2 alpha and 2 beta pleated sheets.
Serum Albumin structure
585 amino acids in a single chain
immunoglobulin structure
2 chains consisting of 2 heavy chains and 2 light chains.
Haemoglobin is..
The red protein, made up of the four chains, within each chain is a heme group which means there are 4 heme groups in total. Each heme group has a iron in the centre of each group at which O2 binds.
Co-operative binding
Seen in the heme group.
Once an oxygen molecule binds, the heme group changes shape in such a way that other sites change to more likely bind oxygen. This method makes red blood cells very good at oxygen accepting when travelling through capillaries when oxygen is diffusing through the alveoli.
Allosteric inhibitation
Haemoglobin is allosterically inhibited by CO2.
Blood concentration of haemoglobin
is approximately 150mg/mL
Haemoglobin concentration within red blood cells is…
approximately 340mg/mL
The structure of haemoglobin
3 dimensional shape determined by protein crystallography by Max Perutz in 1968
Embryos, fetal and adults all have different genes coding for haemoglobin protein
This is because they all have different bit of DNA that code for the particular RNA.
Size of haemoglobin molecule in angstrom
40 A
Size of bond in haemoglobin in Angstrom
1 A
Wavelength of light
500nm or half of a micron
A type of mutation in haemoglobin
Sickle cell disease. The 6th amino acid, where glu changes to val results in the cells structure changing. The haemoglobin ends crystallise (in low oxygen parts of the body) forming sickle cell shape.
Why may sickle cell disease be increased in a population?
May be selected for in high Malarial infected countries as the abnormal haemoglobin copy of the gene protects the malaria parasite from infecting RBC.
Which gene encodes for the Serum Albumin protein?
ALB gene