Structure- a bilipid membraneous layer composed of proteins and carbohydrates. It is fluid like.
Function - the cell membrane separates the cell from its external environment, and is selectively permeable (controls what gets in and out). It protects the cell and provides stability.
Proteins are found embedded within the plasma membrane, with some extending all the way through in order to transport materials.
Carbohydrates are attached to proteins and lipids on the outer lipid layer.
--CYTOPLASM
Structure - The jelly-like substance composed of mainly water and found between the cell membrane and nucleus. The cytoplasm makes up most of the "body" of a cell and is constantly streaming.
Function - Organelles are found here and substances like salts may be dissolved in the cytoplasm.
-- NUCLEUS
Structure - The largest organelle in the cell. It is dark and round, and is surrounded by a double membrane called the nuclear envelope/membrane. In spots the nuclear envelope fuses to form pores which are selectively permeable. The nucleus contains genetic information (DNA) on special strands called chromosomes.
Function - The nucleus is the "control center" of the cell, for cell metabolism and reproduction.
