plasma membranes

Glycocalyx

a capsule made up of a fuzzy coat of sticky sugars

membrane functions

mechanical barrier, electrochemical gradient, cell-to-cell communication and attachment

lipid bilayer

phospholipids arranged in a double layer

2 populations of membrane proteins

1. integral proteins

2. peripheral proteins

integral proteins

span width of membrane - transport

peripheral proteins

attachment to integral proteins or phospholipids - functions as enzymes

ion channels

forms pore through which a specific ion can flow through to get across membrane

carrier proteins

transport specific solutes through membrane

receptor

carries message without chemical - recognizes specific ligand and alters cell's functions in some ways

enzymes

Catalysts for chemical reactions in living things

linker

anchors filaments inside and outside the plasma membrane, providing structural stability and shape for the cell

cell identity markers

help to identify a particular cell

tight junctions

Integral proteins on adjacent cells fuse to form an impermeable junction that encircles whole cell

Prevent fluids and most molecules from moving in between cells

Desmosomes

Anchoring junctions that prevent cells from being pulled apart

gap junctions

hollow cylinders of protein between cells that allow some small molecules to pass between adjacent cells and often used to conduct action potentials

simple diffusion

Diffusion that doesn't involve a direct input of energy or assistance by carrier proteins.

facilitated diffusion

process of diffusion in which molecules pass across the membrane through cell membrane channels

Osmosis

diffusion of water

Tonicity

the ability of a solution to cause a cell to gain or lose water

isotonic

when the concentration of two solutions is the same

Hypotonic

Having a lower concentration of solute than another solution

Hypertonic

Having a higher concentration of solute than another solution.