Lab 5: Osmoregulation Flashcards
Define osmosis:
is the movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration.
What is the difference between hypertonic and hypotonic?
Hypertonic is an area of high solute and hypotonic is an area of low solute concentration.
Define isotonic:
If the concentration of solute and water become equal on either side of the membrane.
Is osmosis active or passive transport?
Passive transport that requires that the membrane restrict the movement of at least one solute but not water (semipermeable).
Define osmoregulation:
is simply the regulation of water and ion concentration in the body.
What moves easier across the plasma membrane? Water or inorganic ions and large organic molecules?
Water, is a relatively small molecule possesiong high kinetic energy and it moves freely across the plasma membrane along any solute gradient that might be present.
Osmoregulators:
Animals that maintain body solute concentrations different from the environment. All freshwater animals are osmoregulators and are usually hyperosmotic to their environment.
Osmoconformers:
Some marine animals do not maintain their osmotic concentrations different from the environment.
What do animals trapped in a tidal pool do to regulate osmosis?
They must be able to adapt to sort term osmotic stress. Thus many are able to osmoregulate at least for a short time.
Are worms osmoregulators or osmoconformers?
osmoregulators
% of initial mass=
Final weight/Initial weight X100
What is the blood concentration of terrestiral invertebrates
between 250 and 500 mOsm
seawater has a mOsm concentration of about
1000 mOsm
The internal tissues of annelids are ——– relative to the freshwater soil surroundings.
hyperosmotic
In annelids how is excretion and osmoregulation accomplished?
By a highly developed organ system call metanephridia.
