Structure of a Cell

Cells are an essential part of the human body, on which the whole functioning of the human body depends. A cell is the building block of the human body. The word cell comes from the Latin word cellula, which means small room. Just like bricks are the building block of any house, a cell is the building block of the human body. Cells perform all kinds of functions – like digestion, respiration, and transportation. A group of cells is called a tissue, and a group of tissues is called an organ. Organs are responsible for performing all types of functions in the body. 

What is a Cell?

A cell is a membrane-bound structure consisting of genetic material, cytoplasm, and other cell organelles. All cell components consist of carbohydrates, lipids, proteins, and nucleic acids. There are two types of cells. These are:

• Prokaryotic cell 
• Eukaryotic cell 

Prokaryotic cells: These types of cells do not consist of a nucleus. Prokaryotic cells are mainly found in single-celled organisms like cyanobacteria and bacteria. An organism that has prokaryotic cells reproduces asexually. 

Eukaryotic cells: These types of cells contain an accurate or well-defined nucleus. Organisms like plants, human beings, and protozoa consist of these types of cells. Organisms with eukaryotic cells reproduce via sexual reproduction. 

Structure of a Cell 

A cell consists of five major parts. These are:

• Cell membrane
• Cell wall 
• Nucleus 
• Cytoplasm 
• Cell organelles 

Cell membrane 

The cell membrane is the most critical part of a cell. It is the outer layer of a cell that facilitates the movement of various compounds inside and outside the cell. It prevents a cell from its external environment. The cell membrane is also called a plasma membrane. It allows the entry of particular components into the cell. Along with this, it also prevents cells from any type of external damage. 

Cell wall 

A cell wall is not present in human beings; it is only present in plant cells. Cell walls of plants consist of pectin, cellulose, and hemicellulose. It is the upper covering of the cell membrane in the plants. Although, it also prevents the plasma and other cell components from the external environment. It is a stiff and rigid substance present in the outer lining of the cell. It protects plants from external and mechanical injuries. 

Cytoplasm 

The cytoplasm is a jelly-like substance present between the cell membrane and nucleus of a cell. Almost every reaction of the cell takes place within this liquid. It consists of cell organelles like ribosomes, mitochondria, endoplasmic reticulum, vacuole, etc. 

Nucleus 

The primary part of a cell is called the nucleus. It is the brain of the cell and regulates the functioning of the cell. The nucleus contains the genetic material where information related to heredity is coded. This heredity material is known as deoxyribonucleic acid (DNA). It gives commands to the cell to perform specific functions. The cell nucleus consists of its own membrane, called the nuclear membrane. The nuclear membrane separates the nucleus from the cytoplasm; this prevents genetic material from getting mixed with the cytoplasm and other components of the cell. 

Cell Organelles 

This part of the cell structure is responsible for all types of cell functioning. Cell organelles are minor components of the cytoplasm responsible for performing various functions of the cells. These cell organelles perform most chemical reactions of cells. There are multiple types of cell organelles present in the cell of humans. Some of these are:

• Endoplasmic reticulum: facilitates the metabolism of steroids, lipids, proteins, and carbohydrates. 
• Golgi apparatus: facilitate transportation of material 
• Ribosome: facilitates protein synthesis 
• Mitochondria: the powerhouse of a cell 
• Vacuoles: stores waste material of the cell. 

Structure of Yeast Cell

Yeast cell is a type of eukaryotic cell. Yeast is a single-celled organism. Its cell consists of all parts which a mature eukaryotic cell contains. Its cells consist of mitochondria, nucleus, Golgi apparatus, endoplasmic reticulum, nucleus, cytoskeleton, and vacuole. All these parts perform different functions. The size of the yeast cell lies between the range of  5×10μm. Yeast cells reproduce by the method of budding. 

Conclusion 

Cells are the main building block of the human body. Scientist Robert Hooke first introduced the cell. The main components of a cell structure are the cell membrane, cell wall, cytoplasm, and nucleus. All biological reactions take place within the cytoplasm of the cell. Although, all the instructions to perform these functions come from the nucleus. Organs are made up of tissues, and tissues are made up of a group of cells. The task performed by any organ is instructed by the nucleus of cells the organs are formed of. Millions of cells are present in the human body, which die and are generated every second.