FACILITATED DIFFUSION: To facilitate something is to help it occur. Remember how some particles where too large to cross the cell membrane by SIMPLE DIFFUSION, or move too slowly? This is where membrane protein channels help out by the diffusion of FACILITATING these particles. Active Transport: The movement of particles AGAINST the concentration gradient. This REQUIRES CELLULAR ENERGY to perform. This is commonly seen in cells, where ions must be pumped against their concentration gradient (by…you guessed it…membrane proteins!) in order to create an electric potential (like a battery) for signal transmission. ENDOCYTOSIS: **”into cell” ENDO A cell envelopes an object of interest until it IN** forms a around the object. The cell membrane then changes shape so that the cell “bubble” membrane is reestablished and a vesicle (containing the object) is on the inside of the cell. When the object is solid (Ex. White blood cell a bacterial cell) it is called PHAGOCYTOSIS “eating” (cell When the object is some amount of liquid it is called PINOCYTOSIS (cell “eating”). “drinking”). EXOCYTOSIS: **“out of cell” EXO think A cell moves a vesicle (typically EXIT** containing wastes) towards the border of the cell membrane. The vesicle and the cell membrane merge expelling the vesicle’s contents outside of the cell and reestablishing the cell membrane. It looks a lot like endocytosis in reverse. ***When comparing the fluid within a cell and a fluid outside of a cell, we can characterize the solution a cell is in by describing it as HYPOTONIC, ISOTONIC, or HYPERTONIC** Hypotonic solution- the concentration of solute particles is greater within the cell than outside of the cell; this will cause to water to enter the cell through osmosis, and the cell will swell (possibly bursting in the process depending on a number of factors).
FACILITATED DIFFUSION: To facilitate something is to help it occur. Remember how some particles where too large to cross the cell membrane by SIMPLE DIFFUSION, or move too slowly? This is where membrane protein channels help out by FACILITATING the diffusion of these particles. Active Transport: The movement of particles AGAINST the concentration gradient. This REQUIRES CELLULAR ENERGY to perform. This is commonly seen in cells, where ions must be pumped against their concentration gradient (by…you guessed it…membrane proteins!) in order to create an electric potential (like a battery) for signal transmission. ENDOCYTOSIS: **”into cell” ENDO IN** A cell envelopes an object of interest until it forms a “bubble” around the object. The cell membrane then changes shape so that the cell membrane is reestablished and a vesicle (containing the object) is on the inside of the cell. When the object is solid (Ex. White blood cell “eating” a bacterial cell) it is called PHAGOCYTOSIS (cell “eating”). When the object is some amount of liquid it is called PINOCYTOSIS (cell “drinking”). EXOCYTOSIS: **“out of cell” EXO think EXIT** A cell moves a vesicle (typically containing wastes) towards the border of the cell membrane. The vesicle and the cell membrane merge expelling the vesicle’s contents outside of the cell and reestablishing the cell membrane. It looks a lot like endocytosis in reverse. ***When comparing the fluid within a cell and a fluid outside of a cell, we can characterize the solution a cell is in by describing it as HYPOTONIC, ISOTONIC, or HYPERTONIC** Hypotonic solution- the concentration of solute particles is greater within the cell than outside of the cell; this will cause to water to enter the cell through osmosis, and the cell will swell (possibly bursting in the process depending on a number of factors).
BIOLOGY%20MIDTERM%20STUDY%20GUIDE%202015.docx