What are Prokaryotes? Prokaryotic cells are cells without a true nucleus and lack membrane-bound organelles. The organisms are known as Prokaryotes – (pro means before; karyon means nucleus); Prokaryotes, therefore, are single-celled organisms (unicellular) that existed before the ones that have nuclei. Prokaryotic cells are therefore the simplest cells that are thought to have evolved before eukaryotic cells and …
What is Nucleus? The Nucleus is the largest organelle of cells that is involved in the control of the cell activities; it constitutes the central, more dense, part of the cell. It is usually rounded or ellipsoid. Occasionally it may be elongated, indented or lobed. It has a diameter of 10 to …
Phagocytosis is the act of ingestion and digestion of microorganisms, insoluble particles, damaged or dead host cells, and cell debris by specific types of cells called phagocytes such as macrophages, neutrophils; Phagocytosis is a form of endocytosis. The word Phagocytosis is derived from the Greek word-Phagein which means to eat; and it involves …
Ribosomes Definition Ribosomes are small granules of RNAs responsible for the production of protein synthesis. The ribosomes of a cell may be freely scattered in a cell cytosol or may be bound to the surface of the rough Endoplasmic Reticulum. What are Ribosomes Ribosomes are small spherical and granular organelles bounded by …
Mitochondria Definition The Mitochondrion (plural = mitochondria) is a membrane-bound cytoplasmic organelle in a cell concerned with the production of energy. It is a rod-shaped or oval-shaped structure with a diameter of 0.5 to 1. It is covered by a bilayered membrane. The outer membrane is smooth and encloses the contents. This …
Lysosome Definition A Lysosome is a small cytoplasmic membrane-bound vesicle found in many types of animal cells that contains hydrolytic enzymes, which play an important role in the degradation of material ingested by phagocytosis and endocytosis. The word Lysosome was derived from the Greek word lysis (loosening) and soma (body). The limiting membrane of …