Cytoplasm is a gel-like substance (shown to the 
right) found inside the membrane (outer surface) of a 
cell. A cell is the smallest, most basic unit of life, that  
is capable of existing by itself. The fluid part of 
The more solid substance in the cytoplasms is 
known as spongioplasm. For organisms known as 
eukaryotes, cytoplasm contains all of the structures 
(known as organelles) in the cell except for the 
nucleus, which is the cell’s control center. 
 
Humans and other complex organisms such as other animals, plants, and fungi, are 
examples of eukaryotes. 
In eukaryotes the nucleus of the cell is separated from the cytoplasm and is located in a 
separate liquid substance known as nucleoplasm. 
Prokaryotes are organisms that have cells without a nucleus. Examples of prokaryotes 
are bacteria. In prokaryotes, all of the contents of the cell are located within the 
cytoplasm. 
 
Most of the activities in the cell happen within the cytoplasm. This 
includes the process of cell division (a way that cells reproduce), 
glycolysis, and metabolism. Glycolysis is the breakdown of glucose 
(a type of sugar) by enzymes, which releases energy. An enzyme is 
a type of protein that helps produce chemical reactions in the body.  
Metabolism is the chemical actions in cells that release energy from 
nutrients or use energy to create other substances. Cytoplasmic 
means relating to cytoplasm. Cytoplasm comes from the Greek word 
"kytos" meaning "a hollow cell," and the Greek word "plasma" 
meaning "thing formed." Put the two words together and you have "a 
hollow (cell) thing formed."