Flashcards in Membrane Transport Deck (22):
What is membrane transport?
The process the cell undergoes to obtain and eliminate substances across the plasma membrane
What feature of the plasma membrane allows it to act as a gate-keeper and a barrier to the movement of molecules?
Which transport mechanisms require no expenditure of energy (ATP) by the cell to move molecules through the plasma membrane?
Passive Transport mechanisms
What is diffusion?
The process of the net movement of particles in a gas or liquid from a place of higher concentration to a place of lower concentration as a result of their constant, spontaneous motion
What is a concentration gradient?
A difference in chemical concentration from one point to another, as on two sides of a plasma membrane
What is a solute?
A substance in a solution dissolved in a solvent, usually the component of a solution present in the lesser amount
What is osmosis?
The diffusion of water
What is the force that drives diffusion?
What is tonicity?
The ability of a solution to change the volume or pressure of a cell by osmosis, whereby the relative concentration of solutes dissolved in solution will determine the direction and extent of diffusion.
What is an isotonic solution?
A solution in which the ECF and the cytosol have the same relative concentration of solutes, so there is no net movement of water through the plasma membrane
What is a hypotonic solution?
A solution in which the concentration of solutes in the ECF is lower than in the cytosol which causes water to move into the cell, increasing the volume and pressure until lysis, or rupture, occurs
What is hemolysis?
The term for the rupturing of red blood cells
What is a hypertonic solution?
A solution in which the concentration of solutes is greater in the ECF than in the cytosol, causing water to rush out of the cell which reduces its volume and pressure to the point the cell shrinks (crenation)
What is crenation?
A term to describe the shrinkage of a blood cell
Why should you not inject a patient with a 10% saline solution? What osmotic effect would that cause?
This would create a hypertonic solution in the patient's body which would result in cell crenation
What is filtration?
A process in which a physical pressure forces fluid through a selectively permeable membrane
In terms of filtration, define selectivity.
Selectivity in filtration means smaller substances can pass through a selectively permeable membrane through tiny gaps while larger substances are retained
What would happen to the filtration rate if you were to apply pressure the the filtration system?
The filtration rate would increase.
What might happen to a filtration system if the water pressure damaged the membrane?
System failure where large particles normally retained would pass through the membrane
Iodine solution can be used to detect which substance?
Benedict solution can be used to test for which substance?