when the concentration of a substance on one side of the membrane is different from its concentration on the other side of the membrane, the substance is said to exhibit a concentration

integrated circuit (ic) is defined as a set of electronic circuits on one small flat piece of semiconductor material, normally silicon. a functional electronic circuit requires transistors, resistors, capacitors, inductors, etc., and the connections between them.

organ system-an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.