Cell Structure and Function Ms. Edwards

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 100,000 cells!

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.

TEM photos of asbestos

SEM photo- Cholera bacteria

STM photos Magnetic Fields Gold molecule Silicon Molecule

Light and Electron Microscopes *Microscopes have 2 properties- magnification and resolution*   1. Magnification and lenses a. The lenses in light microscopes magnify an object by bending the 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- multiply the 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 electrons instead of light to produce a magnified image. Can capture images of objects much smaller than light microscopes.

Specialized Cells   1. In Multicellular organisms, 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.)

Cell Parts Graphic Organizer Function Animal or Plant? Cell Wall Rigid layer around the cell. Helps protect and support the cell. Made of cellulose. Plant

Cell Parts Graphic Organizer Function Animal or Plant? Cell Membrane Controls what goes in to and out of the cell. Both

Cell Parts Graphic Organizer Function Animal or Plant? Nucleus Cell’s control center Both

Cell Parts Graphic Organizer Function Animal or Plant? Nuclear Envelope Surrounds and protects nucleus. Controls what goes in to and out of nucleus. Both

Cell Parts Graphic Organizer Inside nucleus, contain DNA Function Animal or Plant? Chromatin Inside nucleus, contain DNA Both

Cell Parts Graphic Organizer Inside nucleus, where ribosomes are made Function Animal or Plant? Nucleolus Inside nucleus, where ribosomes are made Both

Cell Parts Graphic Organizer Function Animal or Plant? Cytoplasm Region between the cell membrane and the nucleus. The cell’s “glue.” Both

Cell Parts Graphic Organizer Function Animal or Plant? Golgi Bodies Looks like a flattened sac or tube, Cell’s “mail room.” Receive proteins from the ER, package them, distribute them to other parts of the cell. Both

Cell Parts Graphic Organizer Function Animal or Plant? Lysosome Small, round structures that contain chemicals for breaking down materials in cells, Cell’s “clean up crew.” Both

Cell Parts Graphic Organizer Endoplasmic Reticulum (ER) Function Animal or Plant? Endoplasmic Reticulum (ER) Series of passageways, located in cytoplasm, carry proteins and other materials from one part of the cell to another. Both

Cell Parts Graphic Organizer Function Animal or Plant? Mitochondria Rod-shaped, located in cytoplasm, “powerhouse” of the cell. Convert energy in food to a form that cells can use. Both

Cell Parts Graphic Organizer Function Animal or Plant? Vacuole Water-filled sac, storage areas for cells Both- larger in plant cells

Cell Parts Graphic Organizer Green, where photosynthesis happens. Function Animal or Plant? Chloroplast Green, where photosynthesis happens. Plants

Cell Parts Graphic Organizer Function Animal or Plant? Ribosome Located in cytoplasm and attached to parts of ER. Factories that produce proteins. Both

Cell Parts Graphic Organizer Function Animal or Plant? Centriole Barrel- shaped organelles that help with cell division Animal