NCIt definition : A functional area or structure in a cell that is bounded by a lipid-containing membrane.;
Alternative definition : NCI-GLOSS: A small structure in a cell that is surrounded by a membrane and has a
specific function. Examples of organelles are the nucleus (a structure that contains
the cell's chromosomes and is where RNA is made), mitochondria (structures that make
energy for the cell), and lysosomes (sac-like containers filled with enzymes that
digest and help recycle molecules in the cell).;