The cytoplasm is the substance, prevalently colloidal in structure, included between the plasma membrane and the nuclear membrane.
Molecules of smaller metabolites are dissolved in the cytoplasm: macromolecules. These can remain in the solution or gel state, thus causing changes in the cytoplasmic fluidity.
The cytoplasm includes all the functioning substances of the cell (the protoplasm) with the exception of the nucleus; consists of an aqueous solution of enzymes and other macromolecules, ATP, electron transporters, amino acids, nucleotides and inorganic substances, such as phosphates, sodium and potassium, mostly in the form of ions. These enzymes facilitate generalized chemical reactions. However, when these are enzymes that could cause the demolition of organized cell structures, or require an orderly spatial arrangement, then their location is not in the cytoplasm but inside special organelles.
The cytoplasm is divided by a network of membranes, called the endoplasmic reticulum, which continues with the outer membrane of the nuclear envelope, which has the same fundamental structure as the cell membrane and nuclear membranes. The endoplasmic reticulum divides the cell into separate compartments, making it possible for the cell itself to differentiate between chemicals and different activities. Many of the enzymes that carry out these activities are part of the lipoprotein structure of the membranes that form the endoplasmic reticulum. The many folds of the endoplasmic reticulum represent a surface on which many of the cellular biochemical reactions take place.
Click on the names of the various organelles to read the in-depth analysis
Image taken from www.progettogea.com
Edited by: Lorenzo Boscariol
