The cell is defined as the smallest unit of life. It is originated from a Latin word cella meaning ‘small room’ a word used by Hooke (in the year 1665 while observing a cell with the microscope he built by himself) to describe the cells. The cell is considered as a living thing because it has the ability to metabolize, grow and reproduce. Before the invention of microscope, it was difficult to talk about cells as they were tiny and so not visible with the naked eyes but in the 17th century after the invention of the microscope, Robert Hooke and Anton van Leuwenhoek (1675) were able to see and draw the first cells.
In about 1840 to 1855 some German scientist like Matthias Schleiden, …show more content…
MAIN COMPONENT OF THE CELL
Before we look at the internal organization of the cell we need to know that there are 3 main components of the cells which are: Cell membrane:
The cell membrane is a complex barrier or wall that separates every cell from its external environment. The cell membrane which is sometimes called plasma membrane is found in the cytoplasm (jelly-like substance inside the cell) and its function is to protect the cell by allowing certain substances into the cell and also keeping other unwanted substances out. The cell membrane also serves as a support to the cell and helps maintain its shape. The cell is made up of a mix of protein and lipid. The lipid helps to give membranes their flexibility and the protein which helps in the transfer of molecules across the membrane. Phospholipids are the main molecules of the cell membrane. It forms a bilayer in which their hydrophilic (attracted to water) head areas are arranged to face the cytosol (liquid part of the cell) and hydrophobic (repel water) tail areas face outside the cytosol. The lipid bilayer is semi-permeable allowing certain molecules and ions to pass through it. Carbohydrate molecules are also dispersed …show more content…
In the prokaryote cell, all the components of the cell are in the cytoplasm because they do not have a cell nucleus but in the eukaryote cell, the materials in the cell nucleus are separated from the cytoplasm. It is dominated mainly of water, but there are some enzymes like protein salts, organelles (mitochondria, Golgi apparatus and so on) and various organic molecules. The cytoplasm helps in the movements of materials and chemicals around the cell and also eliminates waste in the cell also in the cytoplasm, metabolism and cell division occurs which keeps the cell regulated and