What are the prosthetic groups on haemoglobin called? A haem group
How many polypeptide chains are there in haemoglobin? 4
What is the role of haemoglobin? """To associate with oxygen at the surface
where gas exchange takes place, and to di<span style=""""color: var(--field-fg);
background: var(--field-bg);"""">ssociate with it where tissues require
oxygen</span>"""
What does an oxygen dissociation curve look like? """<img src=""""image-
c955985fe8f106b843e06eb8f3ce96d8ef34fd00.png"""">"""
Why does the oxygen dissociation curve have a sigmoid shape? The shape of
haemoglobin initially makes it difficult for the first oxygen molecule to bind to
haemoglobin, causing the initial shallow gradient<div>Then, the addition of the
first oxygen molecule changes the shape of the haemoglobin, causing it to be easier
to add another oxygen molecule. This is known as <b>positive cooperativity, </b>and
causes the sharp increase in saturation</div><div>As more oxygens are added, it
becomes easier and easier to add more oxygens</div><div>Until the last oxygen needs
to be added, as with the majority of the binding sites full, it is less probable
that the last one will be filled, causing the curve to flatten off at the
end </div>
How can you read the affinity of haemoglobin from an oxygen dissociation curve?
The further to the left the curve, the higher the affinity for oxygen, and
the further to the right, the lower the affinity for oxygen
What is the effect of carbon dioxide on haemoglobin, and what is it called? An
increase in CO<sub>2</sub> concentration causes the blood to become more
acidic, as carbonic acid is formed<div>This breaks some bonds in the tertiary and
quaternary structure of haemoglobin, changing its shape and causing it to have a
lower affinity for oxygen</div><div>This means the oxygen dissociation curve shifts
to the right</div><div>This is known as the <b>Bohr shift</b></div>
Why is the bohr shift helpful? As haemoglobin more readily dissociates with
oxygen in rapidly respiring tissue that is releasing a lot of CO<sub>2</sub>
Why do large organisms have to have a transport system? Once organisms get to a
certain size, their needs cannot be met simply by exchange happening across the
surface of their body. Instead, specialist exchange substances are needed to absorb
nutrients and gases, carry them around the body, and remove waste products
What are the features of a transport system? A suitable medium in which to carry
materials, usually a liquid based on water <div>A form of mass transport where
the transport medium is moved around in bulk over large distances</div><div>A
closed network of tubules that carry the transport medium to all areas of the
organism</div>
Why does the human heart have a double pump system? If the blood went through the
lungs and then straight to the body, it would not go at a high enough pressure, as
the blood has to go through the tiny capillaries in the lungs, meaning it loses a
lot of pressure, and has to be re-pumped, resulting in the double pump system.
What supplies the heart muscle with oxygen? Coronary arteries
What is the structure of the heart? (Draw a diagram with chambers, vessels and
valves) """<img src=""""image-
6ae384ee381330e1ca1ccd17f3eeb93be9276d21.png"""">"""
What does the aorta do? Take blood around the body
What does the vena cava do? Take blood from the body
What does the pulmonary artery do? Take blood to the lungs
What does the pulmonary vein do? Take blood from the lungs
What happens in the cardiac cycle? Diastole- all muscles in the heart relax, and
blood flows into the atria. The semi-lunar valves shut. The pressure in the atria
increases slightly due to the blood being in there.<div>Atrial systole- the atria
contract, causing the pressure in the atria to spike and be larger than that of the
ventricle, causing the atrio-ventricular valves to open, and blood to be pumped
into the ventricles</div><div>Ventricular systole- the ventricles contract, causing
the pressure in the ventricles to rise. Since the pressure in the ventricles in
higher than in the atria, the atrioventricular valves shut, and since the pressure