mass transport Flashcards
what is in the quatenary structure of haemoglobin that allows it to carry out it’s function
it contains 4 polypeptide chains all with an iron prosthetic group that a single oxygen molecule can bind to
with what kind of haemoglobin will more oxygen associate with?
high affinty haemoglobin
where will haemoglobin have a low affinity for oxygen
- places where the is a low concentration of oxygen
- in metabollically active organisms
- when there’s a high CO2 concentration
why is the oxygen dissociation curve an S shape?
as for the first oxygen it is hard to load
the second and third oxygen is easier to load
the fourth oxygen is hard to load
-due to the change of shape of haemoglobin every time an oxygen associates
what does a left shift of the oxygen dissociation curve mean?
- a higher affinity haemoglobin
what does a right shift of the oxygen dissociation curve mean?
-a lower affinity haemoglobin
what is the process of the bohr effect
1- carbon dioxide reacts with water to form carbonic acid (the reaction is catalysed carbonic anhydrase)
2- H+ ions released as well the hydrogen carbonate ion
3- the presence of the H+ ion lowers Hbs affinity for oxygen so oxygen dissociates and diffuses out of the cell
4-H+ and Hb form HHb
in what kind of organisms will low affinity Hb be present? and why?
metabollically active organisms, as oxygen needs to be unloaded quickly for respiration
in what kind of organisms will high affinity Hb be present and why?
organisms that live in a low PPO2 enviroment so Hb can be fully saturated at the low partial pressures
name two features of a transport system
- they have a closed system of tubular vessels
- a form of mass transport in which the transport medium is moved around in bulk over large differences
what is a closed cirulatory system
a circulatory system in which the fluid is contained in vessels
what is a open circulatory system
a circulatory system in which the fluid is not contained in vessels
what are the features of an atrium
it is thin walled
it is elastic
why do ventricles of thicker walls than atria?
as they have to contract strongly to pump blood either to the lungs or rest of the body
what is the function of the atrioventricular valves?
they prevent back flow of blood
what is the function of the aorta?
it carries oxygenated blood to all parts of the body except the lungs
what is the funcation of the coronary arteries?
to carry oxygenated blood to the heart
what is the function of the pulmonary artery?
it carries deoxygenated blood to the lungs
what is the function of the pulmonary vein?
it carries oxygenated blood from the lungs back to heart
what is diastole?
the relaxation of the whole heart both the atria and ventricles
what is the loading of oxygen
the process of which oxygen and haemoglobin bind together
what is the unloading of oxygen
the process by which haemoglobin releases oxygen
what is the role of haemoglobin
to transport oxygen
how is haemoglobin efficient at transporting oxygen
it readily associates with oxygen where gas exchange takes place
it readily dissociates with oxygen at tissues requiring it
why do hameogolbins have different affinities for oxygen
in different organisms hameoglboin have slightly different amino acid sequences
so has a slightly different tertiary and quaternary structure
hence different oxygen binding properties
why do large organisms have a special transport system
as surface area to volume ratio decreases to a point
where needs of the organism cannot be met by the body surface alone
what does the presence of a pump and transport medium depend on
the surface area to volume ratio
how active the organism is
how is the movment of transport medium in vessels occur in animals
via muscle contraction of either body muscles or of a specalised pump organ
how is the movement of transport medium in vessels occur in plants
plants rely on natural processes such as evaporation
what kind of circulatory system do mammals have
A closed double circulatory system
blood is confined to vessels and pass twice through the heart for each complete circuit of the body
why do mammals have a double circulatory system
as when the blood is passed through the lungs it’s pressure decreases
blood is returned to heart to boost it’s pressure so it can flow to the other tissues
outline atrial systole
ventricles relaxed
atria contract decreasing volume of chambers and increasing the pressure
pushing blood into ventricles
outline ventricular systole
ventricles contract
atria relax
decreasing their volume increasing their pressure
pressure in ventricles higher than atria
atrioventricular valve shuts
semi lunar valves open as pressure in ventricles higher than in arteries
outline diastole
atria and ventricles relax
higher pressure in arteries closes the semi lunar valve
blood returns to the heart and fills the atria again due to high pressure in veins
Atrioventricular valve opens as pressure in ventricles falls allowing blood to flow passively from the atria
what is the equation for cardiac output
cardiac output=heart rate x stroke volume
what does haemoglobin and oxygen join together to form in the lungs
haemoglobin and oxygen join together in the lungs to form oxyhaemoglobin
