The structural compartmentation of mammalian cells and the differing functions of these compartments.
All mammals are eukaryotes and therefore have eukaryotic cells. These cells contain several organelles suited to a specific function they carry out within the cell. These eukaryotic cells contain a Nucleus, Mitochondria, Ribosomes, Rough and Smooth endoplasmic reticulum, Golgi apparatus and various other organelles. Most of the organelles are separated from each other by a membrane, these membranes are based on lipid bilayers that are similar to each other. The organelles membrane is there to keep the contents of each organelle separate from the rest of this cell. The membrane consists of a lipid bilayer that may have channels in order to allow the transport of specific molecules which are needed somewhere else in the cell. An example of this is proteins produced by the ribosomes are then moved to the Golgi apparatus in which they are processed and then sent to the correct part of the cell.
Fig 1 – Diagram of a nucleusSource: http://cdn.nursingcrib.com
| The nucleus is a large organelle surrounded by a double membrane nuclear envelope; the nuclear envelope contains many pores to allow substances such as tRNA and mRNA to move between the nucleus and the cytoplasm. The nucleus contains most of the cells genetic material in the form of DNA. The DNA and proteins that make up the contents of the nucleus is known as the chromatin. DNA stored in the nucleus codes for different amino acids and proteins to be produced, depending on which genes are being expressed decides what proteins are produced and ultimately the function of the cell. At the centre of the nucleus is a nucleolus which is where ribosomes are manufactured. A diagram of a nucleus can be seen in figure 1. The double membrane keeps the nucleus separate from all the other organelles and serves as a barrier to prevent molecules diffusing freely into and out of the nucleus. The outer membrane has a...
Bibliography:  Shibata, Yoko; Voeltz, Gia K.; Rapoport, Tom A. (2006). "Rough Sheets and Smooth Tubules". Cell 126(3): 435–439.
 "Regulated Secretion (Golgi): The Movie". North Dakota State University.
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