chapter 3 Flashcards
simple diffusion
The passive movement of a
substance from a region of HIGH concentration to a region of LOW concentration, down the concentration gradient. transports small hydrophobic non polar molecules
concentration gradient
The difference in concentration of a substance on two sides of a membrane.
hydrophilic
‘water loving,’ molecules that interact with water
phospholipids
membrane lipids molecules, two layers make up the cell membrane.
have a phosphate head and fatty acid tail
exocytosis
Bulk transport of molecules OUT of a cell through a vesicle.
osmosis
The passive net movement of water molecules, from a region of low solute (high water) concentration to a region of high solute (low water) concentration.
hypotonic
has a lower concentration of dissolved substances than the cell or solution it is being compared to
types of active transport
protein mediated transport, bulk transport
hypertonic
has a higher concentration of dissolved substances than the cell or solution it is being compared to
protein channel
create holes/pores that penetrate the membrane, enabling target molecules or ions to flow through via diffusion without interfering with one another
ion
An atom or molecule with a net electric charge due to the
loss or gain of one or more electrons.
diffusion
The passive movement of a
substance from a region of HIGH concentration to a region of LOW concentration, down the concentration gradient.
includes simple and facilitated diffusion
solute
A molecule dissolved in a solvent (usually water).
bulk transport
Active movement (uses ATP) of large molecules or groups of molecules across the membrane using vesicles against the concentration gradient
isotonic
has the same concentration of dissolved substances than the cell or solution it is being compared to
carrier protein
proteins that bind to molecules or ions on one side of the membrane and release them on the other
fluid mosaic model
explains the structure of the plasma membrane, and how it is made up of a mosaic of different molecules that float in a fluid-like matrix
active transport
The active movement (uses ATP) of substances from a region of LOW concentration to a region of HIGH concentration, AGAINST the concentration gradient
facilitated diffusion
The passive movement of molecules across a membrane using carrier proteins or protein channels, from HIGH to LOW concentration, down the gradient
protein mediated transport
is the process of moving molecules across a cell membrane using energy-powered proteins (pumps) against the concentration gradient
endocytosis
Bulk transport INTO a cell from the extracellular fluid.
important for all cells as many molecules are too large to transport in other methods
hydrophobic
‘water fearing,’ does not mix with water
types of passive transport
simple diffusion, facilitated diffusion, osmosis
solute concentration
substances (e.g. salt, sugar) that can be dissolved in a solvent (e.g. water)
Is either hypotonic, isotonic, or hypertonic compared to the solution being compared
polar
electrons are not shared equally between atoms in a molecule
non polar
made of atoms that share electrons equally, resulting in an even distribution of charge
