3.3 Exchange Wrong Answers Flashcards
adv of counter current system
blood and water flow in opposite directions maintaining the steepest concentration gradient at all times. blood always passes water with the highest oxygen concentration, diffusion occurs across the whole length of the lamellae
growth of xerophytic plants vs sunflowers
slower growth due to small number of stomata. growth may continue at lower water potentials due to adaptations in enzymes for photosynthesis and respiration
consequence of growing plants in soil with little water
closed stomata so no carbon dioxide upake for photosynthesis
journey of an oxygen molecule into the blood from the alveolus
diffuses across the alveolar epithelium and across the epithelium of the capillary
golgi apparatus role in micelle absorption
modifies the triglycerides and combines them with proteins, they become packaged for release
adv of micelles and droplets
droplets increase surface area causing a high, faster rate of hydrolysis.
micelles carry fa’s and mg’s to the membrane and release them so they can be absorbed by diffusion. micelles make them more soluble in water.
process of micelle absorption
combine bile salts with fatty acids/monoglycerides
make them more soluble in water
releases them across the membrane
absorbed by diffusion
reform triglycerides in cell
moved to membrane by vesicles
to improve scientific drawings
single lines, labels, scale, parts drawn to scale, no shading
lowest blood pressure of all vessels
the vena cava
action of the aorta
elastic recoil of the aortic wall maintains a steady/smooth rate of blood flow
highest ventricular pressure
left ventricle. it pumps blood to the entire rest of the body, not just the lungs.
how does AVV maintain a unidirectional flow of blood
closes when VP higher than AP
opens when AP higher than VP
binding of HmG for sigmoid dissociatin
the first oxygen to bind causes a change in the tertiary structure and causes another binding site to be uncovered so a second molecule can easily bind.
ventricular volume changes connected to valve openings/closings
Ventricular volume large = SL opens
Ventricular vol decreases after SL opens
AV shuts then SL opens
SL shuts then AV opens
consequence of a blockage in lymph system
excess tissue fluid cannot be reabsorbed
air is forced out tracheole ends in movement
gases diffuse faster in air than water so oxygen to respiring cells faster
why do insects pump abdomens when spiracles are closed
to force a mass flow of air into the tracheole ends and increase the concentration gradient for diffusion.
how can xylem cope with high pressures from tension
thickened walls to prevent collapse
ringing in summer vs winter
in summer, higher rate of PS due to higher LI, temperature etc. higher production of sugars so more accumulation around ringed phloem.
high affinity for oxygen means
absorbs more oxygen at lower pp02
hmg structure
2 pairs of polypeptide chains, each with a haem group and Fe2+ ion attached
different primary structure of hmg leads to
different TS so different affinities for oxygen
why does hmg only release one oxygen and reserves 3 on its self when the body is in rest
because if it released them all there would be none in reserve to supply the tissues when the body is more active
benefit of constricting lumen
RBCs are flattened against cell wall, forcing them to go slower so there is more time for diffusion
why do plants need a large surface area
to capture light for PS
mixing of blood in heart
only partially oxygenated and deoxygenated blood reaches the lungs and tissues. the supply of oxygen to the lungs is inadequate so the diffusion gradient decreases. limits rate of o2 uptake.
training affects the heart
builds up heart muscles so stroke volume increases. if cardiac output has stayed the same and SV has gone up that means hear rate has to decrease.
effect on co2 on hmg curve
shifts curve right, hmg less saturated
ice fish can survive in arctic waters without a specialised system
temp low so respiration low so do not need much oxygen. they can survive from dissolved oxygen from the water
translocation
sucrose is actively transported into the sieve tube elements by companion cells which decreases the water potential so water is drawn in by osmosis from the xylem. increases hydrostatic pressure so mass flow of movement down to sink where sucrose is used for respiration or for storage
high temps effect on phloem pressure
higher rates of transpiration as more water evaporates from stomata. higher tension in xylem so less water movement from xylem to phloem, decreasing pressure.
describe cohesion tension theory
water transpired, the lower water potential creates tension. cohesion maintains the column of water
heat treatment effect on xylem
xylem movement is passive so heat does not affect it
