Channel
* All channels are integral membrane proteins.
* Most channels contain water.
* Some channels accumulate silt that needs to be removed
  - carry blood
  - contain blood
  - end at low latitudes
  - facilitate pinocytosis
  - fill with water
  - form helixes
  - pass through penises
* Some channels provide nutrients
  - potassium conductance
* allow ions to move down their concentration gradient primarily by diffusion
  - surface water
* are bodies of water
  - communication
  - linear and direct the flow of things in a certain direction
  - lines of political, social, economic, or national cleavage among groups
* are located in rivers
  - television
  - towns
  - tv
  - waterways
  - open canals that convey floodwater through the valley
  - passage
  - sites
  - television stations
  - transmissions
* are used for boating
  - swims
  - views
  - watching
* improve drainage
  - soil drainage
* includes readsides
  - sections
* induced by rill erosion vary both in their depth and length.
* left by dead roots bring water and oxygen down to the microorganisms living in the soil.
* offer product selections
* provide drainage.
* require a chemical ligand for activation
  - skills
* simply allow ions to pass through the membrane in either direction.

### channel:

Ion channel
* All ion channels open faster as temperature increases.
* Many ion channels are sensitive to other stimuli, such as voltage.
* Most ion channels exist either in an open or closed state.
* act as gates allowing particular ions to enter or leave the cell or organelle
  - pathways for ions across cell membranes
* allow selected ions to cross lipid bilayer membranes.
* are a major class of cellular effectors governing membrane excitability
  - very important topic in molecular biology
  - fundamentally important in the regulation of cellular physiology
  - intrinsic membrane proteins that mediate fast communication in nerve and muscle
  - large molecules with multiple functional domains
  - membrane proteins that allow cells to generate electrical signals
  - membrane-spanning proteinaceous pores
  - of different types
  - pores in the membranes of nerve cells through which sodium flows
* are present in both excitable and non-excitable cells
  - plasma membranes and intracellular membranes
* are proteins in cell membranes that open to allow ions to flow into or out of the cell
  - on the cell surface that open to allow ions to pass through
  - that are integral parts of the membranes of all cells
* are small pores in the membranes of cells that open and close when stimulated
  - which pierce the sarcolemma
* are the molecular building blocks of cell membranes that conduct electrical signals
  - units of electrical signaling in cells
  - tiny molecular pores in cells
  - transmembrane proteins that form pores through which ions can pass
  - transport proteins
  - usually closed and open only in response to specific stimuli
  - vital to most cellular physiological functions in virtually all living organisms
* contain extended columns of water molecules within their transbilayer pores.
* mediate electrical excitability in neurons and muscle.
* permit specific charged molecules, or ions, to enter a cell
  - water soluble molecules and ions to cross the plasma membrane
* provide passageways through which ions can move.
* represent a relatively easy target for pharmaceutical compounds.
* underlie the physiology of excitable membranes.