The cell is a smallest unit of a living organism, that cannot be viewed through naked eyes. Each cell holds many smaller parts inside, with its own function. Human cells vary in function and size. The biggest of all cells, are the egg cells.
The cell is like a factory. It is built according to the way it works. Each cell holds many smaller compartments inside, with its own function in coordination with each other.
The cell consists of the outer cell membrane. Cell membrane, sort and organize the contents of the cell into compartments called organelles. This helps the organelles to function more effectively and in a highly specialized manner.
Cell membrane regulates the transportation of the molecules in and out of the cells. The cell membrane is often called as the plasma membrane, because it is the boundary of the cytoplasm.
It is made up of a lipid bilayer with protein molecules embedded in the cell membrane.
The Nucleus is a very important component, that controls all the activities of the cell. It stores DNA, the instruction manual for how to run a cell function.
DNA is surrounded by a double membranous nuclear membrane. Any molecule that requires to move in or out of the nucleus will move through the pores.
In the center of the nucleus is nucleolus, which is responsible in making ribosomal protections and rRNA.
Ribosomes mainly prepare proteins. These are attached to the rough endoplasmic reticulum (ER) and also found floating inside the cytoplasm. This organelle dose not a have membrane.
Endoplasmic Reticulum (ER) transport proteins that are built by the ribosomes and further transferred to golgi apparatus. There are 2 types of ER Rough ER and smooth ER. ER Rough ER and smooth ER are connected to each other. Proteins
Rough ER contains ribosomes on the surfaces. Here the proteins produced by the ribosomes gets modified and is transported.
Smooth ER has little or no ribosomes on the surface. Smooth ER is responsible to make new membranes for the cell or neutralize the toxins.
Golgi apparatus, is an organelle that modifies, sorts, packages and distributes proteins that are received from the ER. Golgi apparatus also prepares materials that are exported outside the cell. The packages prepared by the gogi apparatus are called vesicles.
Vesicles are the membrane packages of enzymes or proteins. The most important vesicles are peroxisome and lysosomes
Peroxisome are the catalyst enzyme filled membrane packages that can neutralize the toxins
Lysosomes are the digestive enzyme filled membrane packages, that are capable of digesting food, virus, bacteria, etc.
In short whole cell is regulated by the nucleus. Within the nucleus contain DNA within. DNA may send the massage out of the nucleus through nuclear pores, into the cytoplasm. Here massage finds the ribosome to build protein and insert that protein into the rough ER. Rough ER sends proteins into new vesicles and these protein filled vesicles are taken up by golgi apparatus. The golgi apparatus modifies, sorts, packages those proteins and built another vesicles. Depending upon the function of the proteins, it will either produce lysosomes, vacuoles, peroxisome or the proteins transported outside the cell.
Mitochondria are another supremely important organelle inside the cell. This dose not have any role in protein production. This is responsible for energy production, metabolism and cell respiration, hence called as a power house. Mitochondria has its own DNA and its own dedicated set of ribosomes within it. So it can be said as a cell within a cell.
Cell structure also contains cytoskeleton, that functions like supporting materials inside the cell. It maintains the shape of the cell and keep organelles intact. There are two types of cytoskeleton, Microfilaments and Microtubules.
Microfilaments are responsible for the moment of the cell like in muscle cell, the Actin.
Microtubules, the centrioles, are more active during cell devision.
There is some extracellular metrix called collagen, that are responsible for holding the cells together. Without this, the skin becomes wrinkled.