Cell transport and structure review
cell membrane
"gatekeeper" of the cell, regulates the flow of materials into and out of the cell--selectively permeable- some substances can cross, but others cannot
active transport
molecules move from low concentration to high concentration and energy molecules are required to move against the concentration gradient. (requires energy)
endocytosis
movement of large materials into the cell; part of the cell membrane wraps around the particle and engulfs it-active transport
phagocytosis
movement of large particles or whole cells; possible feeding method, or a method of defense to destroy bacteria/viruses- active transport
what does the cell membrane help do?
maintain homeostasis
is the cell wall in bacteria and fungi made of cellulose?
NO
what are all cells made of?
a cell membrane, proteins, and lipids
facilitated diffusion
a molecule, such as glucose, must use a protein channel to cross through the cell membrane (needs assistance)
what is the cell wall of plants made of?
cellulose
hypertonic solution
contains a high concentration of solute, relative to another solution. When a cell is placed in a hypertonic solution, water diffuses out of the cell into the solution to create equilibrium. The cell the shrinks and shrivels up.
hypotonic solution
contains a low concentration of solute, relative to another solution. When a cell is placed into a hypotonic solution the water moves into the cell to create equilibrium. The cell then expands and swells and could possibly explode.
isotonic solution
contains the same concentration of solute as another solution. When a cell is placed in a isotonic solution, water diffuses into and out of the cell at the same rate. The fluid that surrounds the body cells is isotonic.
passive transport
high to low concentration, does not require energy EX: osmosis, diffusion, facilitated diffusion
Which way would the water molecules move in the following scenarios?-potato slice in pure (distilled) water
into the cell
Which way would the water molecules move in the following scenarios?-vegetables are sprinkled with water
into the cell
Which way would the water molecules move in the following scenarios?- cucumber slice in salt water
out of the cell
Which way would the water molecules move in the following scenarios?-salt is poured on a snail
out of the cell
What does the cell membrane let pass through easily?
oxygen, carbon dioxide, and nutrients (because is porous)
what are proteins that work as pumps called?
protein pumps
what else does the cell membrane do?
separate the components of the cell from its environment- what surrounds the cell
Osmosis
the diffusion of water through a selectively permeable (semi-permeable) membrane until equilibrium is reached. *Particles move from an area of high concentration to an area of low concentration*
simple diffusion
the movement of small particles through a selectively permeable membrane without the use of protein or energy, and it doesn't need a channel of any kind, squeezes through the membrane until equilibrium is reached. *Particles move from a high concentration to a low concentration*
pinocytosis
transport of solutes or liquids; cell drinking-active transport
exocytosis
vesicles in cytoplasm fuse with the cell membrane and release their contents into the external environment outside the cell.-active transport
dynamic equilibrium
when the concentration is equal throughout the space, end of diffusion, no NET movement but random movement still occurs
moves water into or out of the cell from where theres high amounts to where theres small amounts, until equilibrium is reached
where does osmosis move water?