A cell is the primary unit of function in our body. Each cell unit comprises various small subunits structured in their forms. Functions of every type of organelle vary from each other to perform the ongoing actions of the cell to keep the cell alive.
There are two kinds of cells; eukaryotic and prokaryotic. Moreover, the difference between these two cells lies because of the nucleus. Prokaryotic cells lack the presence of a nucleus, whereas a eukaryotic cell has a nucleus. Some cell organelles are without membranes, such as ribosomes, some are single membrane-bound, such as vacuole, and some are double membrane-bound, such as mitochondria.
Cell membrane
A cell membrane is a selectively permeable membrane, also known as the cytoplasmic membrane. A cell membrane is made up of proteins and a lipid bilayer. Depending upon the requirement of the cell, the cell membrane allows selective materials to come in or go out of the cell. In an animal cell, one of the primary functions of a cell membrane is to provide shape and structure to the cell and protect its inner . The fluid mosaic model states that the cell membrane comprises a lipid bilayer with protein molecules. These are also subcellular structures.
Cytoplasm
One of the organelles present in both plants and animals is the cytoplasm. It is a gel-like organelle between the nucleus and the cell membrane. The cytoplasm consists of water inorganic and organic compounds. The cytoplasm is one of the primary and essential cell organelles. This is because all the organelles of a cell are embedded here. The cytoplasm mainly provides the place for all the chemical reactions.
Types of Organelles
The human body performs based on the roles every organelle plays. Come, let us have a look at the different types of cell organelles and their function.
Endoplasmic Reticulum
The endoplasmic reticulum is one of the types of cell organelles filled with fluid and a membranous canals network. One of the main functions of the endoplasmic reticulum is to transport materials throughout the cell. Endoplasmic reticulum is two types RERand SER.
Mitochondria
Mitochondria are known as the powerhouse of the cell. Being a double membrane structure, the inner membrane is filled with a substance known as matrix and has finger-like structures known as cristae. It is known as a powerhouse due to its ability to produce energy in the form of ATP. Aerobic respiration process conduct in mitochondria.
Ribosomes
A ribosome is a non-membrane bound structural cell organelle. It mainly comprises protein and RNA and is found in the form of tiny particles. There are two types of ribosomes, namely the 70s and 80s ribosomes. 70s ribosomes are found in the prokaryotic organisms, while 80s ribosomes are found in the eukaryotic organisms. The most crucial function of ribosomes in protein synthesis keeps on with the cell’s survival.
Golgi bodies
Golgi bodies or Golgi apparatus is a membrane-bound organelle comprising finger-like flattened, stacked pouches known as cisternae. The Golgi bodies help transport proteins and lipids to the targeted destination. Apart from transportation, it also helps in modifying and packaging the proteins. It is a cell organelle present in both animal and plant cells. It is found within the cytoplasm.
Centrioles and centrosome
When two organelles, centrioles, are mutually perpendicular, they form a centrosome. Every centriole consists of nine peripheral fibrils of tubulin proteins that are equally spaced, where the fibril is an interlinked triplet. The centriole is a proteinaceous material. The main functions of a centriole are the production of spindle fibre during cell division and the cilia , flagella.
Lysosomes
Lysosomes are spherical bag-like structures which are covered by a single unit membrane. Lysosomes are filled with about 50 different types of digestive enzymes termed as acid hydrolases. Lysosomes are highly polymorphic cell organelle. Because, during functioning, lysosomes have different morphological and physiological structures.
Types of Lysosomes
Primary lysosomes or storage granules – These lysosomes store enzyme acid hydrolases in the inactive form. (Enzymes synthesised on ribosomes in cytoplasm) these are newly formed lysosomes.
Digestive vacuoles or Heterophagosomes – These lysosome forms by the fusion of primary lysosomes and phagosomes. These are secondary lysosomes.
Residual bodies – Lysosomes containing undigested material are called residual bodies. These may be eliminated by pinocytosis. These are also called Telolysosomes. (Tertiary lysosomes) Autophagic lysosomal or cyto lysosomes or autophagosomes – Lysosomes containing cell organelles to be digested are known as Autophagosomes.
Conclusion
Cell organelles form the base of every function in a cell (cell present in any living organism). Organelles can also be differentiated based on the membrane. Many other cell organelles are present in the human body and plants apart from the ones mentioned, namely microbodies, plastids, vacuoles, cilia, flagella, cytoskeleton, and others. The cell organelles carry out every task of providing metabolism, growth, carrying genes, thereby keeping the cells alive. Cell is also called as structural and functional unit of life.