TRANSPORT SYSTEM OF THE CELL Flashcards
all prokaryotic and eukaryotic cells are surrounded by a boundary called_________ that separates it from the outside
plasma membrane or cell membrane
substances dissolved in a solution
solutes
regulates the passage of solutes each as ions and small molecules through biological membranes, which are lipid bilayers that contain proteins embedded in them.
Plasma Membrane/cell membrane
characteristic of a membrane which allows passage of certain molecules while blocking others
semi-permeability
difference in the concentration of solutes in a solution between two regions
concentration gradient
refers to the body fluid outside of the cell
extracellular fluid
primary transport
passive
active
molecules found outside or inside the cell can cross the cell membrane in three ways:
passive
active
bulk
substances move into or out of the cell down a concentration gradient which requirees no energy to be used
passive transport
drives their motion and control their direction
concentration gradient
the movement of particles across the plasma membrane from a higher concentration to regions with lower concentration
diffusion
two types of passive transport
diffusion
osmosis
two types of diffusion
simple diffusion
facilitated diffusion
small and lipid-soluble molecules pass through the semi-permeable membrane
simple diffusion
molecules that cannot move through the membrane on their own are transported using transport proteins
facilitated diffusion
transport proteins
channel
carrier
form pores in the membrane allowing ions to pass
channel
specific molecules and transport them across the plasma membrane
carrier
the process of transporting water across the membranes. it diffuses water from areas of higher water concetration to areas of lower water concentratrion.
osmosis
a transport of individual molecules by membrane proteins against their concentration gradient which requires energy
active transport
the exchange of large molecules in the cytoplasm and extracellular fluid of the cell
bulk transport
large molecules enter the cell by a process called ________, wherein the cell membrane bends inward or invaginates, forming a vesicle containing the macromolecule to be transported.
endocytosis
materials for export, like proteins produced in the ribosomes and packaged in the golgi apparatus, are secreted out of the cell
exocytosis
enclosed sacs in the cytoplasm that is usually used for storage and support
vesicles
