Biology Cell Report
There are many parts of a cell, they all have specific duties, and are all needed to continue the life of the cell. Some cells exist as single-celled organisms that perform all of the organism's metabolism within a single cell. Such single-celled organisms are called unicellular. Other organisms are made up of many cells, with their cells specialized to perform distinct metabolic functions. One cell within an organism may be adapted for movement, while another cell carries out digestion. The individual cells no longer carry out all life functions, but rather depend on each other. Many-celled organisms are called multicellular. When a group of cells function together to perform an activity, they form a tissue. The cells of a human are organized into tissues such as muscle and nerve tissues. Plant tissues include those of the stem and root. Many cells in tissues are linked to each other at contact sites called cell junctions. Cell junctions help maintain differences in the internal environment between adjacent cells, help anchor cells together, and allow cells to communicate with one another by passing small molecules from one cell to another. Groups of two or more tissues that function together make up organs. An organ system is a group of organs that work together to carry out major life functions.
Eukariotic Cell Structure:
Boundaries and Control:
Plasma Membrane - The plasma membrane is sometimes called the cell membrane, or the cellular membrane. It is the outermost part of the animal cell, and it's purpose is to enclose the cell, and change shape if needed. The cell membrane is capable of allowing materials to enter and exit the cell. Oxygen and nutrients enter, and waste products such as excess water leave. The plasma membrane helps maintain a chemical balance within the cell.
Cell wall - The cell wall is an added boundary to the cell. It is relatively inflexible, and surrounds the plasma membrane. The cell wall is much thinker than the plasma membrane and is made of different substances in different organisms. The cells of plants, fungi, almost all bacteria, and some protists have cell walls. Animal cells have no cell walls. Plant cells contain cellulose molecules, which form fibers. This fibrous cellulose of plants provides the bulk of the fiber in our diets. Chitin, a nitrogen-containing polysaccharide, makes up the cell walls of fungi.
Nucleus - The nucleus of the cell is the organelle that manages cell functions in a eukariotic cell. The nucleus contains DNA, the master instructions for building proteins. DNA forms tangles of long strands called chromatin, which is packed into identifiable chromosomes when the cells are ready to reproduce. Also within the nucleus is the nucleolus, a region that produces tiny cell particles that are involved in protein synthesis These particles, called ribosome's, are the sites where the cell assembles enzymes and other proteins according to directions of the DNA.
Assembly, Transport, and Storage:
Cytoplasm - The material that lies outside the nucleus and surrounds the organelles is the cytoplasm, a clear fluid that is a bit thinner than toothpaste gel. It usually constitutes a little more than half the volume of a typical animal cell.
Endoplasmic Reticulum - The endoplasmic reticulum (ER) is a folded membrane that forms a network of interconnected compartments inside the cell. The ER membranes contain the enzymes for almost all of the cell's lipid synthesis, they serve as the site of lipid synthesis in the cell. The ER functions as the cell's delivery system. Some parts of the ER are studded with ribosome's. In the cell, the sites of protein assembly are the ribosome's.
Golgi Apparatus - The Golgi apparatus's main purpose is to store materials. The Golgi apparatus is a series of closely stacked, flattened membrane sacs that receives newly...