biology Flashcards
hypertonic
is a solution that has a higher solute concentration outside the cell than inside
isotonic
equal concentrations of impermeable solutes on either side of the membrane
hypotonic
has a lower concentration of solutes than another solution
hydrophobic
a property of a substance that repels water
hydrophilic
having a strong affinity for water
passive transport
a type of membrane transport that does not require energy to move substances across cell membranes
active transport
the process of moving molecules across a cellular membrane through the use of cellular energy
extracellular
situated or occurring outside a cell or the cells of the body
intracellular
the inside region of cells and what you find there
solute
a substance that can be dissolved by a solvent to create a solution.
solution
a mixture in which molecules of one substance are distributed evenly in another.
how does water get out of a cell
pinocytosis
endocytosis of solid material, such as bacteria
phagocytosis
endocytosis of a fluid material, such as lipids
facilitated diffusion
when molecule is to big (like glucose) and can’t fit through the phospholipid bilayer so it has to go through a transmembrane protein
osmosis
the movement of water molecules from a solution with a high concentration of water molecules to a solution with a lower concentration of water molecules, through a cell’s partially permeable membrane.
active transport
the process of moving molecules across a cellular membrane through the use of cellular energy
bulk transport
a type of active transport that moves particles, such as large molecules, parts of cells, and even whole cells, into a cell
exocytosis
moving materials from within a cell to the exterior of the cell.
endocytosis
the process by which cells take in substances from outside of the cell by engulfing them in a vesicle.
cholesterol
increases the lipid-packing density and maintains high membrane fluidity
transmembrane proteins
gateways to permit the transport of specific substances across the membrane.
carbohydrates
help to protect the cell from the outside world
polar and non polar
Polar atoms and molecules interact freely with water, while nonpolar atoms and molecules resist this interaction.
How does surface area to volume affect diffusion of molecules into the cell?
As volume and surface area increase, the volume increases faster
Why are cells so small?
so that they can maximize their ratio of area to volume
