Chapter 5: Homeostasis & Transport Flashcards
Osmosis
The diffusion of water across a selectively permeable membrane
Diffusion
The spontaneous movement of particles of any kind Down a concentration gradient; that is movement of particles from where they are more concentrated to where they are less concentrated
Concentration gradient
An increase or decrease in the density of a chemical substance within a given region. Things tend to move down their concentration gradient.
Hypotonic
In comparing two solutions referring to the one with the lower concentration of solutes
Hypertonic
In comparing two solutions referring to the one with the greater concentration of solutes
Isotonic
Having the same solute concentration as another solution
Facilitated diffusion
The passage of a substance across a biological membrane down its concentration gradient, aided by specific transport proteins
Ion channels
Proteins embedded in the cell membrane that carry ions across the cell membrane from areas of greater to lower concentration
Cytolysis
Bursting of a cell due to water pressure from within
Plasmolysis
Shrinkage of a cell due to water loss
Turgor pressure
Pressure of water against cell membrane and cell wall from within
Passive transport
Movement of materials across the cell membrane requiring NO CELL ENERGY, but using the energy of the moving molecules (as they try to spread out evenly/balance)
Active transport
The movement of a substance across a biological membrane against it’s concentration gradient, aided by specific transport proteins and requiring the input of energy (often as ATP)
Entropy
A measure of disorder, or randomness. One form of entropy is heat, which is random molecular motion.
Endocytosis
Taking large molecules INTO a cell by forming a “pocket” vacuole around them
