Masss Tramsport Flashcards
Structure of Haemoglobin
-Haemoglobin is a tetra meter consisting of 4 polypeptide chain called globing
-consist of 2 alpha , 141 2 beta chains 146 aa long
-attached to each chain is a haem group
Affinity
Chemical attraction
Dissociating
Process by which Haemoglobin releases its oxygen
Associating
Processes by which Haemoglobin binds with oxygen
High affinity
Take up oxygen more easily but release less easily
Low affinity
Takeout ocugen less easily but releases more Easily
Why Haemoglobin from different species have different affinities for oxygen
Each has slightly different primary structure thus has a different tertiary and quaternary structure. This means they have a different affinity for oxygen.
Gas exchange surfaces
High o2 conc
Low co2 conc
High affinity for oxygen
Oxygen is associated
Respiring tissues
Low oxygen conc
High carbon dioxide conc
Low affinity for oxygen
Oxygen is disassociated
Partial pressure of oxygen
The amount of oxygen that can combine with Haemoglobin is determined by the oxygen concentration
The pressure of a single gas component in a. Mixture of gases it correspond to the total pressure which the single gas component would exert it it alone occupied the whole volume
Oxygen dissociation curves
When the po2 falls at first this has little effect on the percentage saturation
As blood passes through the heart and arteries the po2 drops slightly but the Haemoglobin does not lose much oxygen
Haemoglobin saturation at high values
Lungs at sea level :pO2 of 100mmhg Haemoglobin is 98% saturated
When the pO2 in the lungs declines below typical sea level values Haemoglobin stil has a high affinity for o2 and remains almost fully saturated
Haemoglobin saturation levels at low Po2
At a po2 of 40mm hg Haemoglobin has a lower affinity for oxygen and is
Describe how Haemoglobin loads and unloads oxygen in the blood
1)oxygen loads and binds to Haemoglobin in areas of high partial pressure like in the alveoli in the lungs this causes association
2)Haemoglobin has a high affinity for oxygen
3)muscles and tissues have low po2 and lower affinity which causes disassociation and this causes unloading of oxygen
How does Haemoglobin transport oxygen from a gas exchange surface to respiring cells
-binding of oxygen molecules to the Haemoglobin molecules
-causes a change in the shape of the hemoglobin molecule, allowing it to pick up more oxygen as it travels through the lungs.
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How are the properties of the Haemoglobin that an organism contains suited to its wat of life
Features of transport systems
1)suitable medium to carry materials
2)transport medium is moved over large distances in bulk
3)
Open systems
1)blood is pumped by the heart into an aorta which branches into a number of arteries
2)these open into a series of blood spaces
3)blood moves through the tissues under low pressure gradually percolating back into the heart via open ended veins
4)distribution of blood is poorly controlled
Closed systems
1)animals with a higher metabolic rate needs fast and efficient delivery of oxygen and glucose to the tissues and removal of carbon dioxide and other waste products from the tissues
2)only a closed system can do this
3)blood is pumped rapidly around the body under high pressure and back ngo the heart
myocardium
thick muscular layer of uscle heart wall
cardiac muslce
specialised muscle cells of the heart joined by intercalated discs
myogeneic
cardiac muscle is self exciting
valves
prevent backflow and make heart sounds “lubb” dubb`’
at rest heart beat should be
72bpm
