Cytoplasm is the jelly-like substance that fills cells. It contains all the internal components of a cell, called organelles, except for the nucleus. Clear and composed of 80% water, the cytoplasm is the location for most of a cell's internal functions. Cytoplasm is responsible for moving materials throughout the cell and aids in cell replication. It holds of the chemicals and other materials that are necessary for the life and growth of the cell. It serves to maintain the shape and structure of the cell, and also allows the cell to move. Cytoplasm is composed of three major elements: cytosol, cytoplasmic inclusions and organelles.
Cytosol is the component that is most responsible for the structure of the cell. Composed of water, salt and organic molecules, cytosol is everything not contained within organelles. The cytosol makes up most of the cytoplasm and contains the filaments that form the cytoskeleton, which is what forms the shape of the cell and allows it to move. Another major function of the cytosol is to facilitate the movement of materials throughout the cell and between organelles.
Cytoplasmic inclusions are contained in the cytosol, but are considered separate entities. They are not present in all cells and vary in their content. Inclusions in the cytosol include stored nutrients, cell waste and secretory materials and pigment granules. The cytoplasm is responsible for moving nutrients to the organelles where they are used for energy. It also facilitates the removal of waste from the cell.
Organelles are structures within the cell that perform a specific function. The cytoplasm serves to hold the organelles in place. Literally meaning "little organ", organelles are usually enclosed in their own lipid bilayer. There are many cell components that qualify as organelles. The two major organelles found in most eukaryotic cells are mitochondria and chloroplasts. Mitochondria supply energy to the cell and direct its growth. Chloroplasts are found in plant cells and extract energy from light sources. They also remove oxygen from carbon dioxide and water.