mass transport Flashcards
Haemoglobin
quaternary structure protein
2 alpha chains
2 beta chains
4 associated haem groups in each chain containing Fe2+
transports oxygen
affinity of haemoglobin
the ability of haemoglobin to attract/ bind to oxygen
saturation of haemoglobin
when haemoglobin is holding the maximum amount of oxygen it can hold
loading/ unloading of haemoglobin
binding/ detachment of oxygen to haemoglobin
also known as association and disassociation
oxyhaemoglobin dissociation curve
oxygen is loaded in regions with high partial pressures
unloading in regions of low partial pressure
oxyhaemoglobin dissociation curve shifting left
Hb would have a higher affinity for oxygen
load more at the same partial pressure
becomes more saturated
adaptations in low-oxygen environments
cooperative binding
Hbs affinity for oxygen increases as more oxygen molecules are associated with it
when one binds. Hb changes shape meaning others bind more easily
explaining S shape of curve
how CO2 affects haemoglobin
When carbon dioxide dissolves
in liquid, carbonic acid forms
decreases pH causing Hb to
change shape
affinity decreases at respiring
tissues
more oxygen is unloaded
Bohr effect
High carbon dioxide partial pressure
causes oxyhaemoglobin curve
to shift to the right
oxyhaemoglobin dissociation curve shifting right
Hb has lower affinity for oxygen
unloads more at the same
partial pressures
less saturated
present in animals with faster
metabolisms that need more
oxygen for respiration
e.g. birds/rodents
closed circulatory system
Blood remains within blood
vessels
name different types of blood vessels
Arteries, arterioles, capillaries,
venules and veins
structure of arteries
Thick muscular layer
thick elastic layer
thick outer layer
small luman
no valves
capillary endothelium
Extremely thin
one cell thick
contains small gaps for small
molecules to pass through (e.g.glucose, oxygen)
capillaries
Form capillary beds
narrow diameter (1 cell thick) to slow blood flow
red blood cells squashed
against walls shortens diffusion pathway
small gaps for liquid / small
molecules to be forced out
arterioles
Branch off arteries
thickest muscle layer to restrict
blood flow
thinner elastic layer and outer
layer than arteries as pressure
lower
tissue fluid
Liquid bathing all cells
contains water, glucose, amino
acids, fatty acids, ions and
oxygen
enables delivery of useful
molecules to cells and removal
of waste
tissue fluid formation
At arteriole end, the smaller
diameter results in high
hydrostatic pressure
small molecules forced out
(ultrafiltration)
red blood cells / large proteins
too big to fit through capillary
gaps so remain
reabsorption of tissue fluid
Large molecules remaining in
capillary lower its water
potential
towards venule end there is
lower hydrostatic pressure due to loss of liquid
water reabsorbed back into
capillaries by osmosis
role of lymph in tissue fluid reabsorption
Not all liquid will be reabsorbed by osmosis as equilibrium will
be reached
excess tissue fluid (lymph) is
absorbed into lymphatic system and drains back into
bloodstream and deposited
near heart
cardiac muscle
walls of heart having thick muscular layer
unique because it is:
myogenic - can contract and
relax without nervous or
hormonal stimulation
never fatigues so long as
adequate oxygen supply
coronary arteries
Blood vessels supplying cardiac muscle with oxygenated blood
branch off from aorta
if blocked, cardiac muscle will
not be able to respire, leading to myocardial infarction (heart
attack)
adaptation of left ventricle
Has a thick muscular wall in
comparison to right ventricle
enables larger contractions of
muscle to create higher
pressure
ensures blood reaches all body
cells
veins that connect to the heart
Vena cava - carries
deoxygenated blood from body to right atrium
Pulmonary vein - carries
oxygenated blood from lungs to left atrium
arteries connected to the heart
Pulmonary artery - carries
deoxygenated blood from right ventricle to lungs
Aorta - carries oxygenated blood from left ventricle to rest of the body
valves within the heart
ensure unidirectional blood flow
semilunar valves are located in aorta and pulmonary artery near the ventricles
atrioventricular valves between atria and ventricles
opening and closing valves
Valves open if the pressure is
higher behind them compared
to in front of them.
AV valves open when pressure
in atria > pressure in ventricles
SL valves open when pressure in ventricles > pressure in arteries
the septum
Muscle that runs down the
middle of the heart
separates oxygenated and
deoxygenated blood
maintains high concentration
of oxygen in oxygenated blood
maintaining concentration
gradient to enable diffusion to
respiring cells
cardiac output
Volume of blood which leaves one ventricle in one minute.
heart rate = beats per minute
heart rate x stroke volume
stroke volume
Volume of blood that leaves the heart each beat
measured in dm^3