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?