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Unit 6: Cell Structure and Function. Overview of Cells. Cells are the basic unit of structure and function in living things. Cells perform basic functions of life: Obtaining oxygen Getting rid of wastes Obtaining food Growing. Overview of Cells. Cells are REALLY small!
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Unit 6: Cell Structure and Function
Overview of Cells • Cells are the basic unit of structure and function in living things. • Cells perform basic functions of life: • Obtaining oxygen • Getting rid of wastes • Obtaining food • Growing
Overview of Cells • Cells are REALLY small! • One cm2 of your skin’s surface has more than 100,000cells!
First Observation of Cells • The invention of the microscope made the discovery of cells possible. • Microscope-an instrument that makes small objects larger
Development of Cell Theory Schleiden, Schwann, and Virchow- a. German Scientists that concluded plants and animals are made of cells.
Cell Theory Cell Theory- widely accepted explanation of the relationship between cells and living things. a. All living things are composed of cells. b. Cells are the basic units of structure and function in living things. c. All cells are produced from other cells.
History of the Microscope 1674- Leeuwenhoek’s simple microscope. Mag.= 266x 1590- 1st compound microscope- Zacharias & Hans Janssen 1660- Hooke’s compound microscope 1886- Compound Light Microscope- Ernst Abbe and Carl Zeiss. Mag.= 1000x
History of the Microscope 1933- Transmission Electron Microscope (TEM)- Ernst Ruska. Mag.= 500,000x 1981- Scanning Tunneling Microscope (STM)- Mag.= 1,000,000x 1965- Scanning Electron Microscope (SEM)- Mag.= 150,000x. 3D image of specimen.
STM photos Magnetic Fields Gold molecule Silicon Molecule
Light and Electron Microscopes Light and Electron Microscopes *Microscopes have 2 properties- magnification and resolution* 1. Magnification and lenses a. The lenses in light microscopes magnify an object bybendingthe light that passes through them.
Light and Electron Microscopes b. Convex Lens- center of the lens is thicker than the edge. Incoming light rays bend as they pass through a convex lens. When the light hits the eye, the eye sees the image as larger than it really is.
Compound Microscopes 2. Compound Microscope Magnification a. Compound- more than one lens. One lens is close to the eye and the other lens is near the specimen. b. Total Magnification- multiplythe magnification of the 2 lenses. Ex: First lens = 10x Second lens= 40x Total magnification: 10 x 40 = 400x
Compound Microscopes 3. Resolution- the sharpness of the image. Allows us to focus on individual parts of the object.
Compound Microscopes 4. Electron Microscopes- use a beam of electronsinstead of light to produce a magnified image. Can capture images of objects muchsmallerthan light microscopes.
Specialized Cells 1. In Multicellularorganisms, cells are specialized to perform different functions. Ex:Nerve cells, skin cells, blood cells, etc.
Specialized Cells 2. Levels of Cellular Organization a.Cell b.Tissue-Group of similar cells that work together (nervous, muscle, etc.) c.Organ-Different kinds of tissues that work together (brain, heart, kidney, etc.) d. Organ System- Group of organs that work together (respiratory, urinary, reproductive, etc.)
