Cell transport is the movement of particles and it takes place because cells are trying to maintain balance (homeostasis).
2 main categories of cell transport 1=passive transport 2=active transport
Moves molecules across the cell membrane from an area of HIGHER concentration to an area of LOWER concentration Concentration Gradient It does NOT require cells to expend energy a. Diffusion b. Facilitated diffusion c. Osmosis
a. DIFFUSION = General term for the movement of molecules from an area of HIGHER concentration to an area of LOWER concentration until it reaches EQUILIBRIUM
= Passive movement of small molecules across a membrane with the help of proteins -Channel Proteins -Carrier Proteins
c. Osmosis = Diffusion of WATER Molecules! NOTE: Cell membranes are completely permeable to water with the help of aquaporins
DIRECTION OF OSMOSIS is due to the solution 1. Isotonic = solution when the concentration of solutes (particles) outside and inside the cell are EQUAL!
Cells will retain its normal shape!
2. Hypertonic Solution The concentration of solute molecules outside the cell is HIGHER than the concentration inside the cell Example…PLASMOLYSIS!
Cells will SHRINK!
The concentration of solute molecules outside the cell are LOWER than the concentration in the cell cytoplasm Cells will
Cells will SWELL!
Movement of Materials Through the Cell Membrane
Moves molecules across the cell membrane from an area of LOWER concentration to an area of HIGHER concentration It requires cells to expend energy a. Transport proteins b. Exocytosis c. Endocytosis
a. Transport proteins: actively transport small molecules across cell membrane
Vesicles made by the cell fuse with the cell membrane, releasing their contents into the external environment (Exit)
c. Endocytosis (ENTER) Process of taking material INTO the cell by means of infoldings or pockets of the cell membrane that pinch off into vesicles within the cell. 1. Pinocytosis= vesicle contains fluids ( cell drinking ) 2. Phagocytosis=vesicle contain large particles ( cell eating )