cells

Cells are composed of oxygen, hydrogen, carbon, and nitrogen, which contain most important organic compounds in a cell are proteins, nucleic acids, lipids, and carbohydrates,Water makes up 60 to 65 percent of the cell.Some cells are complete organisms, as the unicellular bacteria and protozoa; others, such as nerve, liver, and muscle cells, are components of multicellular organisms,Cells range in size from the smallest bacteria like mycoplasmas, which are 0.1 micrometer in diameter, to a egg …

…to describing structures (morphology). A central concept in modern cytology is that each structure has a function that may be understood as a series of biochemical reactions. The understanding of these functions has been greatly aided by the development of cell fractionation techniques, using an ultracentrifuge to separate specific intracellular structures from the rest of the cell. Another technique is tissue culture, by which specific kinds of cells can be isolated and grown for stuDY.