The Heart And Blood Flashcards
(7 cards)
What is co-operative binding in haemoglobin
Binding of the first oxygen molecule changes hydrogen bonds in the tertiary/quaternary structure of haemoglobin, uncovering another haem group to bind to, making it progressively easier for each molecule of oxygen to bind. Equally, loosing an oxygen molecule makes it progressively easier for the other O2 to unbind with haemoglobin.
What is a haem group?
Iron inorganic ion where O2 binds to.
What biological molecule is haemoglobin and what is its structure?
A protein - quaternary structure with 4 polypeptide chains.
What are the two types of haemoglobin that oxygen can bind to more easily?
Fetal haemoglobin and myoglobin
What does the term affinity mean?
How easily (readily) haemoglobin binds with oxygen.
High affinity =HB easily associates (binds) to oxygen.
Low affinity = HB easily dissociates (releases) with oxygen.
How does a sigmoidal curve graph provide evidence for cooperative binding?
In low partial pressure of oxygen it is harder to saturate haemoglobin with oxygen and there is little increase of saturation. At higher partial pressure there is higher saturation as oxygen can bind easier.
How can a lower affinity help a specie of greater levels of activity?
If it has lower affinity it can dissociate with oxygen easier from HB. This means more oxygen can be provided for respiration to allow the species to have more energy and a greater level of activity.
