Haemoglobin Flashcards
What is electrophoresis
method of analysing molecules by measuring their migration in electric field
often use some sort of support (e.g. agarose for DNA, polyacrylamide for proteins) which acts as a sieve through which the molecules migrate
What is spectrophotometry
way of analysing molecules on basis of their spectral properties
can be used to follow changes in oxygen binding by haemoglobin, and this is a method used when checking the respiratory status of newborn infants
Why do foetal red blood cells produce haemoglobin F rather than haemoglobin A?
To facilitate oxygen transfer from maternal red blood cells to foetal red blood cells
Haemoglobin F has a higher affinity for oxygen than haemoglobin A
A medical student measures the activity of malate dehydrogenase by spectrophotometry. Using a 1cm width cuvette, she monitors the production of NADH at 340 nm over 5 minute period when the enzyme malate dehydrogenase is introduced to a solution of malate.
After 5 minutes, the absorbance of the cuvette contents has increased from 0 units to 0.585 units.
Given that the molar extinction coefficient for NADH at 340nm is 6220 M-1 cm-1, what is the concentration of NADH in the cuvette?
Rearrange A = E × c × ℓ to give C= A/E ℓ
C =0.585/6220 x 1 = 0.00009405 M or 94.1 μM
What is the role of the Rapoport–Luebering shuttle in red blood cells?
To generate 2,3-BPG which is important for the cooperative binding of oxygen to haemoglobin A.
Reasons causing oxygen-Hb dissociation curve to shift left
Low [2,3-DPG], hypoxia and high pH
What is MCV
Mean Cell Volume (fl)
dividing total vol. of red cells by number of red cells
What is MCH? Equation
Mean Cell Haemoglobin (pg)
Amount of haemoglobin in a given volume divided by number of red cells
Hb/RBC (g)
What is MCHC? Equation
Mean Cell Haemoglobin Concentration (g/l)
Hb/Hct (g/L)
What is haematocrit (Hct)
% of vol. of a blood sample occupied by red ccells
What are the most frequently used stains
Haematoxylin + Eosin (H&E)
Haematoxylin = purple-blue component that binds to acidic components of cells –> DNA
Eosin = pinkish stain, binds to protein components, esp. in cytoplasm
