BIO 121 Test II
Terms
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- Tonoplast
- Single membrane around vacuole
- Middle Lamella
- Sticky material that forms between two new cells (pectin)
- Actin Filaments
- cell division, cell motility, made of actin
- Intermediate Filaments
- Fibrous proteins, mechanical strength, made of keratin
- Organization of Centrioles, Cilia, and Flagella
- 9 pairs of microtubuoles and 2 solitary microtubuoles in the center
- Resolving power of the human eye
- 1/10 mm
- Resolving power of the compound light microscope
- .25 micrometers
- Resolving power of the ultraviolet microscope
- 0.1 micrometer or 100 nanometers
- Resolving power of the electron microscope
- 0.2 nanometer
- If the wavelength of white light is 500nm, what is its resolving power?
- 250nm
- Source of electrons in TEM
- Filament (usually Tungston)
- Focusing of electron beam in TEM
- Magnetic field organizes electrons in beams
- Scattering of electrons from collisions with air molecules in TEM
- System is put in vacuum
- Seeing electrons with the naked eye in TEM
- Image is projected onto flourescent screen
- What improves the contrast in a TEM?
- heavy metal salts
- Six steps to preparing a speciman for the TEM
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1. Fixation
2. Dehydration
3. Embedding in plastic
4. Sectioning (diamond/glass knife)
5. Sections float on water
6. Sections stained with heavy metal salts - What are the heavy metal salts used to improve contrast in the TEM?
- Uranium (uranyl acetate) and lead (lead citrate)
- What are the five steps in freeze fracturing?
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1. Freeze specimen
2. Sectioning fractures along plances of weakness
3. Subliming off water in a vacuum
4. Coating cut surfaces with heavy metal and/or carbon
5. Dissolving away the tissue with acid (leaving only the heavy metal/carbon) - Robert Hooke
- Cork cells, cellulose cell walls
- Anton van Leeuwenhoek
- Protozoa, algae, bacteria, and yeast cells
- Jean Baptiste Lamarck
- Suggested cellular nature of all living organisms
- Rene Dutrochet
- All animals and plants are basically made of cells
- Robert Brown
- Recognized and named nucleous, but didn't recognize the functional role
- Matthais Schleiden
- Plants are all composed of cells
- Theodor Schwann
- Animals are all made of cells, clear formulation of cell theory, functional and structural importance of cell contents
- Rudolf Virchow
- Every cell from a cell (cell division makes cells)
- Johannes Purkinje
- Protoplasm
- Plasmodesmata
- Connecting strands of protoplasm between cells that may serve as intercellular channels for materials
- Types of junctions between cells
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1. Desmosomes
2. Tight
3. Gap - Peroxisomes
- Break down hydrogen peroxide into oxygen and water
- Solution
- Particles uniformly distributed, transparent, particles < 1nm
- Suspension
- Particles settle out, cloudy, particles > 100nm
- Colloid
- particles range from 1nm to 100nm
- Dicontinuous (internal) phase of a colloid
- dispersed particles
- Continuous (external) phase of a colloid
- Medium in which particles are dispersed
- Emulsion
- Liquid dispersed in liquid (milk)
- Plasmolysis
- Shrinking of cell due to a hypertonic environment