What is a Cell?
A cell is defined as the very smallest structural and functional unit and a building block of any living organism. It is always considered as membrane-bound and is made up of cytoplasm, genetic material, and other cell organelles or components of the cell. All cells are made from the same major classes of organic molecules such as nucleic acids, proteins, carbohydrates, and lipids.
A collection of cells that have the same stimulating and life giving functions is called a tissue. When tissues are conjoined to perform their functions, organs are developed and from those organs, bodily functions are developed. Therefore, it can be said that the human body will fail to perform its basic bodily functions if there were no tissues. On the other hand, if there were no cells, there would be no tissues either. So the entire process of cell development and tissue development is interrelated.
Cell Structure
Talking about cells like prokaryotic and eukaryotic cells, they share some significant similarities in terms of structure. One dominant structural resemblance between them is the presence of plasma membranes in both of them. Plasma membrane is responsible for transferring substances in both of the cells both from inside and outside the cell. Moreover, the interior structure of both the cells is termed as cytoplasm. The presence of ribosomes that specializes in protein coalescence is another structural similarity between prokaryotic and eukaryotic cells.
Cell Theory
As far as cell theory goes, it is a universally accepted fact that “living organisms are made up of cells.” Moreover, cell theory has also established that “all cells come from pre-existing cells” and “cells are the structural unit of all living organisms.” Cells are also known as the “basic unit of reproduction.”
Discovery of Cell
The discovery of cell was made by Robert Hooke in 1665 when various microscopic advancements were taking place. He came to discover cells when he was observing some slices of bottle cork under microscope. He gave the name of his discovery “cells” which means “a small room” in Latina. However, Hooke didn’t realize at that time that the things that he was observing were, in fact, alive. It was the observation of Anton van Leewenhoek which proved that cells were living organisms as his observation told that cells were motile objects.
Characteristics of Cells
The interior structure of a cell is made up of organelles. Of all those organelles, the most vital one is the mitochondria as it is responsible for transporting energy to the cell. Moreover, the endoplasmic reticulum works as an active transporting system for the cell which is a product of the cell’s tubular network. Besides that, the role of being the packaging system of the cell is fulfilled by the Golgi apparatus. Lysosomes fulfill the function of being digestive enzymes and ribosomes synthesize protein for the cells. Another important characteristic of the cell is that the organelles are protected by a jelly-like substance called the cytoplasm.