a. Cell membrane: The cell membrane, also known as the plasma membrane, is a thin, flexible layer that surrounds the cell and separates its internal environment from the external environment. The membrane has several functions, including controlling the movement of substances into and out of the cell, maintaining cell shape and structure, and providing protection to the cell.
b. Cell wall: The cell wall is a rigid layer that surrounds the cell membrane of plant, fungal, and bacterial cells. It provides support and protection to the cell, helps maintain the cell's shape, and prevents excessive water uptake by the cell. The cell wall is made up of various polysaccharides, such as cellulose in plants and chitin in fungi.
c. Cytoplasm: The cytoplasm is a jelly-like substance that fills the cell and contains various organelles, such as mitochondria and ribosomes. It is involved in many cellular processes, including protein synthesis, energy production, and cell division.
d. Mitochondria: Mitochondria are organelles found in eukaryotic cells that are responsible for producing energy in the form of ATP (adenosine triphosphate) through a process called cellular respiration. They have their own DNA and can reproduce independently from the rest of the cell.
e. Nucleus: The nucleus is a membrane-bound organelle that contains the cell's genetic material in the form of DNA (deoxyribonucleic acid). It is responsible for regulating gene expression, cell division, and the synthesis of RNA (ribonucleic acid). The nucleus also contains a nucleolus, which is involved in the production of ribosomes.