Cell
Cell are the basic building blocks of all living things.All living beings are composed of cells and they are the smallest units of a structure in every living thing. Some organisms are unicellular in which the entire organism is a single cell, such as a bacterium or yeast. On the other hand, in plants and animals, cells are the building blocks of these multicellular organisms. A cell is an individual unit in the sense that it is capable of metabolizing its nutrients, synthesizing essential biomolecules, providing its energy, and replicating itself to produce the next generations. There are three main parts of a cell that include the cell membrane, the nucleus, and the cytoplasm. The cell is surrounded by the cell membrane which regulates the transport of substances into and out of the cell. The nucleus is another cellular structure that contains the nucleolus and the majority of the cell’s DNA is found there. RNA synthesis also happens there. The cytoplasm refers to the fluid inside the cell. Cells have many organelles that include mitochondria, which are responsible for supplying the energy necessary for cell function and survival; lysosomes, which engulf and remove unwanted and harmful materials within the cell; and the endoplasmic reticulum and the Golgi apparatus, which play central roles in maintaining the internal organization of the cell. Various molecules are synthesized, processed, sorted, and finally targeted to specific locations within the cell by these two organelles.Plant cells also contain chloroplasts, which mediate the function of photosynthesis. The space within the cytoplasm that is not occupied by these organelles is called the cytosol. The cytosol has an organized framework of fibrous molecules which is called the cytoskeleton. The cytoskeleton provides a scaffold due to which a cell gains its shape and can move as well as organelles can move inside the cell. The cytoplasm is where most chemical reactions take place and where most proteins are made. More than 30 trillion cells are present in the human body. [Tahirah Yasmin]