4.1 Flashcards
3 types of passive transport
simple diffusion, osmosis, facilitated diffusion. All move from high to low concentrations and do not require energy
What is osmosis
simple diffusion of water down its own gradient
What is simple diffusion
substance moves down its concentration gradient without the use of a carrier molecule - Lipids/o2/co2 across cell membrane
What is facilitated diffusion
substance moves across membrane with assistance of transport proteins - ions/polar molecules
active transport
Moves against concentration gradient, requires transport protein, requires energy - sod-pot pump
An isotonic solution is
Solutes in equilibrium
A hypertonic solution is
High concentration of solutes
A hypotonic solution is
Low concentration of solutes
What is endocytosis and what are the three types of endocytosis?
Ingestion of large molecules and substances that can’t pass through plasma membrane. Pinocytosis, Receptor mediated, phagocytosis. Surrounds and ingests. Requires energy
Pinocytosis
ingestion of a liquid
Phagocytosis
Ingestion of a particulate, such as bacterial cell or organic frangment
Receptor mediated endocytosis
Molecules bind to receptors in plasma membrane. When enough accumulate, the pit deepens, seals and is incorporated into the cell as a vesicle.
Exocytosis
discharge of materials from membrane bound packages that fuse with the membrane and release their contents to the outside of the cell. Requires energy
membrane trafficking
constant pinching and fusion of vesicles, endo and exocytosis
Diffusion
net movement of molecules down a concentration gradient
