1 Cell Structure - 7 The invention of the microscope made discovery and study of cells possible. Robert Hooke used a simple microscope and named the compartments he saw in a sliced cork sample and called them cells.
Anton van Leeuwenhoek developed a simple light microscope and further described cells. compound microscopes have 2 or ore magnifying lens and allow us to study small objects. Schleiden said all plants are made of cells. Schwan said all animals are made of cells. Virchow said that all cells came from preexisting cells. Eventually all these observations of many other scientists were summarized into the cell theory. Cell Theory 1. All organisms are made of 1 or more cells. 2. Cell is basic unit of organization and function of an organism. 3. All cells come from preexisting cells. Electron microscopes made study of extremely small objects not seen by light microscope.1000 times greater. works with a beam o electrons focused by electromagnets. Specimen is dead and in a vacuum. 2 TYPES OF CELLS. Prokaryotes lack internal structures that are surrounded by membranes. have no true nucleus most are 1 celled organisms. Eukaryotes.> Contain internal membrane bound structures called organelle Can be 1 celled or multi-cellular Organelles divide cell into compartments with a membrane Each organelle ( or compartment)becomes specialized and allows several chemical reactions to be carried out at the same time
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Cell Structure - 7
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EURKARYOTE CELL STRUCTURE. Cells have a plasma or cell membrane that is a boundary with environment. Membrane controls what enters and exits cell and maintains a balance within cell. Plants, fungi some bacteria, and protists have a cell wall. Cell wall made o cellulose and gives support to plants. In fungi cell wall is made up o chitin. ORGANELLES & OTHER CELL PARTS
Nucleus Is the largest organelle and contains the DNA that manages the cell's functions. Has DNA that manages the cell. Is porous so material can enter and leave nucleus. DNA made of long strands o chromatin which packs into chromosomes when time to reproduce cell. Nucleous Found in nucleus. It is involved in protein synthesis. Ribosomes are sites in cells where enzymes and other proteins are assembled. Cytoplasm Surrounds organelles outside the nucleus. It is a clear fluid that is jelly like. It makes up a little more than 1/2 the cell's volume. Golgi Endoplasmic recticulum delivers materials to ribosomes to be assembled as protein. Rough ER has ribosomes attached Smooth ER is without ribosomes. Ribosomes assemble proteins. Some lipids are made on ER.
apparatus Stacked flattened membrane sacs Receive the proteins and lipids from ER f or distribution them to plasma membrane. Repackaged proteins in vesicles that are pinched off and expelled from cell or keep in cell or later use. Vacuoles Are sacs of fluid surrounded by a membrane. Used or storage of food, enzymes, and other cell products or wastes. In some 1 celled organism they collect excess water and pump it out o cells. In plants, large vacuoles store water and food. Lysomes Contain digestive enzymes that digest worn out cell parts and other cell parts.
Cell Structure - 7 Mitochondria Where food molecules are broken down to release energy. Like many other organelles are folded to give greater surface area. Cholorplasts Are found in green plants and some protists. Can transform light energy into chemical energy. Have chlorophyll, a green pigment, that traps light energy and makes plants green. Chloroplasts are an organelle types called plastids. Some store starches and lipids. Some have pigments or color and are named after their color. o Ex. Carotene, Cytoskeleton Composed of tiny rods and filaments to form cells framework. Made of mostly micro-tubles and microfilaments. o Microtubles are thin hollow walled proteins tubes. o Microilaments are thin solid proteins fibers. Some cells have cilia and flagella which are structures used for motion or movement of fluids over cell. Cilia are short hair-like and usually in large numbers. flagella are longer an whip-like and usually only 1 or two to cell.
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Plant and animal cells have similar structures and functions but each kind of cell is adapted to the organism that it composes. CELL ORGANIZATION. Cells Unicellular - one celled. 1 cell performs all function of life. Multi-cellular - made o many cells. different cells may perform a special function o lie. ex. or reproduction, movement, or digestion. tissues A group o cells that function together ex. nerve, muscle, bone, stems, roots. organ 2 or more tissues acting together a ex. stomach,. brain organ system. A group of organs that operate together are called an ex. nervous system, digestive system