Cell Component and their Functions
The cell body (soma) is the factory of the neuron. It produces all the proteins for the dendrites, axons and synaptic terminals and contains specialized organelles such as the mitochondria, Golgi apparatus, endoplasmic reticulum, secretory granules, ribosomes and polysomes to provide energy and make the parts, as well as a production line to assemble the parts into completed products.
Cytosol - Is the watery and salty fluid with a potassium-rich solution inside the cell containing enzymes responsible for the metabolism of the cell.
1. Nucleus - Derived from the Latin word for "nux", nut, the nucleus is the archivist and the architect of the cell. As archivist it contains the genes, consisting of DNA which contains the cell history, the basic information to manufacture all the proteins characteristic of that cell. As architect, it synthesizes RNA from DNA and ships it through its pores to the cytoplasm for use in protein synthesis.
The.Nucleolus is an organelle within the nucleus which is involved actively in ribosome synthesis and in the transfer of RNA to the cytosol.
2. Golgi Apparatus - membrane-bound structure that plays a role in packaging peptides and proteins (including neurotransmitters) into vesicles.
3. Polyribosomes - there are several free ribosomes attached by a thread. The thread is a single strand of mRNA (messenger RNA, a molecule involved in the synthesis of proteins outside the nucleus). The associated ribosomes work on it to make multiple copies of the same protein.
4. Neuronal membrane (see next box)
5. Mitochondrium - this is the part of the cell responsible for the supply of energy in the form of ATP (adenosine triphosphate). Neurons need an enormous amount of energy. The brain is one of the most metabolically active tissues in the body. In man, for example, the brain uses 40 ml of oxygen per minute. Mitochondria use oxygen and glucose to produce most of the cell's energy.
The brain consumes large amounts of ATP. The chemical energy stored in ATP is used to fuel most of the biochemical reactions of the neuron. For example, special proteins in the neuronal membrane use the energy released by the breakdown of ATP into ADP to pump certain substances across the membrane to establish concentration differences between the inside of the neuron and the outside.
6. Rough Endoplasmic Reticulum and Smooth Endoplasmic Reticulum (7) - A system of tubes for the transportation of materials within the cytoplasm. It may have ribosomes (rough ER) or no ribosomes (smooth ER). With ribosomes, the ER is important for protein synthesis.