TRANSPORT ACROSS THE MEMBRANE Flashcards
COMPOSITION OF PLASMA MEMBRANE
55% proteins
25% phospholipids
13% cholesterol
3% carbohydrates and
4% other kinds of lipids
semipermeable, which means that it allows certain molecules and ions to pass across it and prevent others from doing so
CELL MEMBRANE
In active transport, substances are transported against the gradient by the use of
ENERGY
Ingestion of large particles is accomplished through
PHAGOCYTOSIS
Ingestion of dissolved substances
PINOCYTOSIS
net movement of molecules or ions from a region of higher solute concentration to a region of lower solute concentration
DIFFUSION
rate of diffusion is measured by
the number of diffusing molecules passing through the membrane per unit time
The rate at which a substance diffuses depends on
a. magnitude of the concentration difference across the membrane
b.size, and shape of the particles of solute
c. temperature
TRUE OR FALSE:
Higher temperature increases the rate of the diffusion process because it increases the kinetic energy of molecules.
TRUE
the kinetic movement of ions and molecules through membrane spaces without necessarily binding with the carrier proteins along the membrane
SIMPLE DIFFUSION
requires ions and molecules to bind first to the carrier proteins so they can enter the cell.
FACILITATED DIFFUSION
the simple diffusion of a solvent (water) across a membrane
OSMOSIS
solvent or water molecules move from the solution that is more dilute to the solution in which there is a higher solute concentration
OSMOSIS
higher in a solution with greater solute concentration
OSMOTIC PRESSURE
the movement of solvent stops when
A. the two solutions reach equal concentration
B. when the osmotic pressure is equal on both sides of the semipermeable membrane.
the separation of molecules on the basis of size and by their ability to diffuse through a semipermeable membrane
DIALYSIS
TRUE OR FALSE:
Dialysis makes use of diffusion across a selective permeable membrane.
TRUE
They contain small pores and allow the ions or crystalloid (such as sugar and salt which form two solutions with water) to pass through but not colloidal particles because they are much larger in size.
PARCHMENT AND CELLOPHANE
Thus, in a mixture of crystalloid and colloids placed in a dialyzing bag that is immersed in distilled water, what is dialyze?
crystalloids dialyze out through the parchment
In a mixture of crystalloid and colloids placed in a dialyzing bag that is immersed in distilled water, what is left inside?
COLLOIDS
the solution outside the dialyzing bag
DIALYSATE
In the test for proteins, what will appear if the proteins are present?
white precipitate or turbidity
What is an indicator for the presence of the reducing sugar?
YELLOW OR RED PRECIPITATE
any external solution that has a high solute concentration and low water concentration compared to body fluids. Thus, it has a tendency to shrink.
HYPERTONIC
