Cell Related Terms and Definitions

  • Biology: Biology is a branch of science which deals with the study of living organisms.
  • Cytology: Cytology or cell biology is the study of the structure and function of the cell.
  • Cell: Cell is the functional and fundamental unit of life.
  • Cellular Respiration: Cellular respiration is a process by which cells produce the energy that is stored in food.
  • Cell Cycle: The cell cycle is the process of cell duplication and division, which includes interphase and mitotic cell division.
  • Plasma membrane: Plasma membrane is the semi-permeable lipoprotein covering that act as a selective barrier between the cell`s cytoplasm and its outside environment which protects the cell from its environment. It is also known as the cell membrane, cytoplasmic membrane or plasmalemma.
  • Mycoplasma: Mycoplasma is the simplest and smallest cellular organism.
  • Prokaryote: Prokaryote is the organism or cell (usually unicellular) which lacks a true nucleus.
  • Eukaryote: Eukaryote is the organism which contains a true nucleus.
  • Nucleoid: Nucleiod is the nuclear region within a prokaryotic cell that contains all or most of the genetic material(genophore) but not isolated by the membrane.
  • Endocytosis: Endocytosis is the process by which substances are brought into the cell from their external environment through the cell membrane. In this case, substances include fluids, proteins, electrolytes, and other macromolecules.
  • Exocytosis: Exocytosis is the energy-consuming process that forces out materials from within a cell to the extracellular space through the active transport by fusing with the cell membrane.
  • Phagocytosis: Phagocytosis is the process by which a cell ingests or engulf particulate material or other cells using its plasma membrane.
  • Pinocytosis: Pinocytosis is the process by which a cell ingests or absorbs of proteins and other soluble materials from outside the cell and brings them within the cell.
  • Desmosis: Desmosis is the thickened area of plasma membranes of two adjacent cells from which radiates out fine tonofibrils.
  • Cell wall: Cell wall is the rigid exoskeletal structure which encloses and protects the contents of most plant and some bacterial cell.
  • Plasmodesmata: Plasmadesmate is the cytoplasmic bridge between adjacent plant cells.
  • Protoplasm: Protoplasm is the ‘physical basis of life’.
  • Cytoplasm: Cytoplasm is that portion of cellular protoplasm which occurs between the plasma membrane and nuclear membrane.
  • Organelles: Organelles are the structures in the cytoplasm of a cell which take an active part in the life and function of the cell, for example, chloroplast.
  • Endoplasmic reticulum: Endoplasmic reticulum is the interconnected system of membrane-bounded tubules and vesicles which form irregular reticulum or network in the cytoplasmic matrix.
  • Golgi body: Golgi body is the cytoplasmic organelle which bears a complex system of tubules and vesicles and which is related to the production of cellular secretion.
  • Lysosome: Lysosome is the single membrane-bounded organelle which contains many kinds of hydrolytic enzymes which are involved intracellular digestion.
  • Suicidal Bag: Lysosome is also known as a suicidal bag.
  • Vacuole: Vacuole is the fluid filed cytoplasmic structure for storage of excess water, waste products, soluble pigments, etc.
  • Residual Body: Residual body is the vacuole containing indigestible substances.
  • Primary Lysosome: Primary lysosome is the small storage vesicle formed from the endoplasmic reticulum (ER).
  • Heterophagosome: It is the digestive vacuole resulting from the ingestion of foreign substances by the cell.
  • Autophagosome: Autophagosome is the specialized lysosome with a double-layer structure containing some parts of the cell during the process of digestion.
  • Mitochondria: Mitochondria is the membrane-bounded organelle that generates chemical energy in the form of ATP. It is also known as the powerhouse of the cell.
  • Crista: Crista (cristae: plural) is the infolding part of the inner mitochondrial membrane.
  • F1-particle: It is the membrane-bounded structure which is located on the matrix side of the cristae. It is also known as Fernandez Moran subunit.
  • Plastid: Plastid is the cytoplasmic organelle of the plant cell which is involved in synthesis and storage of starch, pigments and other products in plant cells.
  • Chloroplast: Chloroplast is the chlorophyll-containing plastid where photosynthesis occurs.
  • Thylakoid: Thylakoid is the flattened vesicle found in the chloroplast where the light-dependent reactions of photosynthesis take place.
  • Granum: Granum is the stalk of the thylakoid.
  • Chromoplast: Chromoplast is the yellow-orange coloured plastid.
  • Ribosome: Ribosome is the cytoplasmic granule composed of RNA and protein, where protein synthesis takes place.
  • Microtubules: Microtubules are the fine tubular structure which is made up of tubulin protein.
  • Cilia: Cilia (Cilium: singular) are the minute hair-like projections which occur from the surface of certain cells such as Paramecium.
  • Flagellum: Flagellum (flagella: plural) is the whip-like extended structure of the cell surface.
  • Basal body: Basal body is the cylindrical structure which is located at the base of each flagellum or cilium. It is also known as kinetosome.
  • Centriole: Centriole is the hollow cylindrical microtubular organelle which is involved in the organization of the spindle.
  • Cytoskeleton: Cytoskeleton is a complex cytoplasmic network of microtubules and microfilaments, which is located frequently near the cell membrane.
  • Nucleus: Nucleus is a part of a cell containing chromosomes; it controls the cell division and metabolism.
  • Karyotheca: Karyotheca is the double-membrane surrounding the nucleoplasm and genetic material.
  • Karyolymph: Karyolymph is the clear fluid material within the nuclear membrane.
  • Nucleolus: Nucleolus is the spheroidal body within the nucleus of a eukaryotic cell that makes the ribosomal subunits from proteins and rRNA. ( ribosomal RNA).
  • Chromatin: Chromatin is the genetic material (DNA and proteins) within the nucleus of a eukaryotic cell which forms a chromosome.
  • Cell Theory: Cell theory is one of the basic principles of biology, stating that the cell is the basic unit of life, and all living organisms are made from cells.
  • Centromere: Centromere is a region of the chromosome that joins two sister chromatids which plays an essential role in proper chromosome segregation during the cell division.
  • Chromatid: Chromatid is a replicated chromosome with two identical daughter strands attached by a single centromere. In this case, the two strands are separated to form individual chromosome during the cell division.
  • Chromosome: Chromosome is a long, rod-shaped or thread-like structure that carries heredity information (DNA) which is found in the nucleus of the cell.
  • Cytokinesis: Cytokinesis is a part of cell division where cytoplasm of a single eukaryotic cell is divided to produce two distinct daughter cells.
  • Cytosol: Cytosol is a semi-fluid substance of a cytoplasm found inside of cells in which organelles, proteins, and other cell structures float. It is also known as a cytoplasmic matrix or intracellular fluid, or groundplasm.
  • Organelles: Organelles are tiny specialized structures within a cell( such as mitochondria, ribosomes, endoplasmic reticulum, etc.), that carry out specific functions such as controlling cell growth and producing energy, which is necessary for regular cellular operation.
  • Peroxisome: Peroxisome is a membrane-bounded organelle which is found in the eukaryotic cell that contains enzymes involved in a variety of metabolic reactions and produces hydrogen peroxide as a by-product.