Science Cell Membrane

Temperature

A measure of the average energy of motion of the particles of a substance.

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Equilibrium

When particles are at equal concentration

dynamic equilibrium

condition of continuous, random movement of particles but no overall change in concentration of materials

Phospholipids

a lipid containing a phosphate group in its molecule

phosopholipid bilayer

composition of the plasma membrane, two layers of phospholipids arranged tail-to-tail

cell membrane

A cell structure that controls which substances can enter or leave the cell.

selectively permeable

a property of cell membranes that allows some substances to pass through, while others cannot

Diffusion across cell membrane

movement of substance from high to low concentration across the membrane

Osmosis

Diffusion of water through a selectively permeable membrane

In the egg lab, this was the hypotonic solution

water

In the egg lab, this was the hypertonic solution

corn syrup

What did Vinegar do to the egg?

Dissolved the shell and made it bigger

Solute

A substance that is dissolved in a solution.

Hypertonic

when comparing two solutions, the solution with the greater concentration of solutes

Hypotonic

Having a lower concentration of solute than another solution

Isotonic

when the concentration of two solutions is the same

Salt water fish in in fresh water

Water would go into the fish

A trout into salt water

Water would leave the fish

What is distilled water?

Water with no solutes.

passive transport

the movement of substances across a cell membrane without the use of energy by the cell

facilitated diffusion

Movement of specific molecules across cell membranes through protein channels

active transport

the movement of materials through a cell membrane using energy

carrier proteins

a protein that transports substances across a cell membrane

protein pumps

transport proteins that require energy to do work

Solvent

A liquid substance capable of dissolving other substances

Solution

A mixture that forms when one substance dissolves another.

Endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

What powers diffusion?

The energy of the particles.

Hydrophilic

water loving

Hydrophobic

Water fearing

fluid mosaic model

model that describes the arrangement and movement of the molecules that make up a cell membrane

The cell membrane is permeable to

Small particles

high concentration

when molecules are more crowded

low concentration

when molecules are less crowded

polar

describes a molecule in which the positive and negative charges are separated