<span>A scenario where a cell may be needed to perform a form of endocytosis is when transporting large molecules.
A scenario where a cell may be needed to perform a form of exocytosis is when releasing the large molecule from the cell. The movement of macromolecules of polysaccharides or proteins out of or into the cell is known as Bulk transport.
Bulk transport is of two types which include endocytosis and exocytosis whereby both require an expenditure of energy. Exocytosis materials are being exported out of the cell via secretory vesicles.
Golgi complex they do package macromolecules into transport vesicles which travel to and spill its content out of cells. Exocytosis is very much important in the expulsion of waste materials out of the cell and also in products secretion. Endocytosis is the process where materials move into the cell.
Endocytosis is divided into the three types which include pinocytosis, phagocytosis, and receptor-mediated endocytosis.</span>
Tobacco mosaic virus (TMV) is a simple rod-shaped helical virus that contains single stranded RNA situated at its middle and is surrounded by a protein coat called capsid. After tobacco mosaic virus enters its infected host cells through mechanical inoculation, it removes its capsid to release its single stranded viral nucleic acid which is then transported into the nucleolus. The single stranded viral RNA actuates the production of specific enzymes (RNA polymerases) and it also produces another RNA strand (replicative RNA). The new viral-RNAs are transported from the nucleus into the cytoplasm and functions as messenger-RNAs (mRNAs). Each mRNA, ribosomes, and t-RNA, of the infected host cell all controls the production of protein subunits (capsomeres). After the production of the preferred capsomeres, the new viral-RNAs arrange the capsomeres around it which lead to the production of a complete virus particle (virion). The viruses then migrate from one cell to another. Hence, creating organized infection.
