Cytoplasm and Cell Nucleus Functions

Human and animal cells are composed of a wide variety of items. These items within the cell membrane are known as organelles. They carry out vital roles in cell functions. The cytoplasm makes up the vast majority of the cell, but one of the most important parts, if not the most important, is the cell nucleus.

The cytoplasm is the fluid material and organelles within the cell, not including the nucleus. A small amount of energy for use by the cell can be produced by chemical processes that occur in the cytoplasm. This contributes to our survival, as it is the key process in red blood cell energy metabolism; it is called anaerobic metabolism be­cause it doesn't require oxygen.

The cell nucleus is bounded by its own double membrane. The nucleus controls ac­tions that occur in the cell, using hereditary material called deoxyribonucleic acid (DNA). DNA is the "code book" that contains directions for making substances the cell needs. It consists of genes on chromosomes.

This "code book" remains in the nu­cleus of the cell, but conveys its information to other cell organelles by way of a simi­lar molecule called ribonucleic acid (RNA). The RNA has the responsibility of transcribing the information of the DNA and moving out through pores in the nuclear membrane to the cytoplasm. The RNA then carries the code to protein-synthesizing sites called ribosomes. There, the RNA code is translated into a specific protein. With the exception of the red blood cell, all cells have one or more nuclei.

DNA has the secondary task of cell replication. DNA is a double-stranded mole­cule, and when the cell begins to divide, each strand is separated and an identical copy of each is made. Thus, each new DNA contains one new strand of DNA and one strand from the original DNA. In this way, the genetic code is preserved from one cell generation to the next. The mitochondria contain their own DNA, so they reproduce themselves independent of action in the nucleus.

The transport of proteins, vitamins, and other material from the cytoplasm to the nucleus also occurs through pores in the nuclear membrane as just mentioned. These small molecules serve a variety of functions, including the activation (or inactivation) of certain parts of the DNA chain.

DNA is an important part of any living organism as it is what both separates and unites different organisms. Genetic mutations give rise to new forms of life, and evolution favors the organisms which have the DNA that allow them to survive in their respective environments.

Written by, Barbara Johnson For more great information on enrolling in CNA Training or obtaining your RN license visit