Damn Near Everything There Is To Know About Cells: Essay -- essays res

Damn Near Everything There Is To Know About CellsBiology Cell ReportThere ar many parts of a cellular telephone, they all have specific duties, and are allneeded to continue the life of the cell. Some cells exist as single-celledorganisms that perform all of the organisms metabolism within a single cell.Such single-celled organisms are called unicellular. Other organisms aremade up of many cells, with their cells change to perform distinctmetabolic courses. One cell within an organism may be adapted for movement,while another cell carries out digestion. The several(prenominal) cells no longercarry out all life functions, but rather depend on each other. Many-celledorganisms are called multicellular. When a group of cells function together toperform an activity, they form a tissue. The cells of a human are organizedinto tissues such as muscle and nerve tissues. Plant tissues include thoseof the base of operations and root. Many cells in tissues are linked to each other atconta ct sites called cell junctions. Cell junctions help maintain differencesin the internal surroundings between adjacent cells, help anchor cells together,and allow cells to communicate with one another by passing small molecules fromone cell to another. Groups of ii or more tissues that function togethermake up organs. An organ system is a group of organs that work together tocarry out major(ip) life functions.Eukariotic Cell StructureBoundaries and ControlPlasma Membrane - The plasma membrane is sometimes called the cell membrane, orthe cellular membrane. It is the outermost part of the tool cell, and itspurpose is to enclose the cell, and change shape if needed. The cell membraneis capable of allowing materials to enter and exit the cell. Oxygen andnutrients enter, and waste products such as excess weewee leave. The plasmamembrane helps maintain a chemical balance within the cell.Cell wall - The cell wall is an added boundary to the cell. It is relativelyinflexible, and surround s the plasma membrane. The cell wall is much thinkerthan the plasma membrane and is made of different substances in differentorganisms. The cells of plants, fungi, almost all bacteria, and some protistshave cell walls. tool cells have no cell walls. Plant cells containcellulose molecules, which form fibers. This fibrous cellulose of plantsprovides the bulk of the fiber in our diets. Chitin, a nitr... ... pigments, molecules that give color.Structures for Support and LocomotionThe cytoskeleton is a network of thin, fibrous elements that act as a sort ofscaffold to provide support for organelles. It also helps maintain cell shapein a manner similar to the way poles maintain the shape of a tent. Thecytoskeleton is usually composed of microtubules and microfilaments.Microtubules are thin, hollow cylinders made of protein. Microfilaments arethin, solid protein fibers. Microtubules and microfilaments make up most of thesytoskeleton.Cilia - Cilia are only contained in some cells. They ar e short, numerous,hairlike projections out of the plasma membrane. Cilia tend to occur in largenumbers on a cells surface, and their beating activity is usually coordinated.Flagella - Flagella are longer projections that move with a whiplike motion.Cells that have flagella only have one or two per cell. In single-celledorganisms, cilia and flagella are the major means of locomotion. Sperm cells ofanimals and some plants move by means of flagella. Organisms that contain manycells, including humans, have cilia that move fluids all over a cells surface,rather than moving the cell itself.