Compound Light Microscope

Making a Wet Mount Slide Cover Slip Lower slowly

Microscope Basics: (On other PP) A. field of view—how much of the slide you are able to see through the microscope -The lower the magnification, the wider the field of view is. B. resolution—the sharpness of the image as seen through the microscope

The Cell I.History of the Microscope A. Robert Hooke (1665) gave the cell its name after looking at cork through his simple microscope.

Hooke’s Microscope

B. Anton van Leeuwenhoek improved the microscope; was the first to describe bacteria and red blood cells. C. Robert Brown discovered the nucleus.

Leeuwenhoek’s Microscope

D. Schleiden (botanist) and Schwann (zoologist) and Virchow—Their work led to the cell theory. E. Electron microscopes were invented in 1940.

Scanning Electron Microscope (Open)

Influenza virus

Tobacco Mosaic Virus

Salmonella Bacteria

Diatom

Flea

II. The Cell Theory states: 1. All organisms are composed of one or more cells. 2. The cell is the basic unit of organization of organisms. 3. All cells come from preexisting cells.

III. Two Basic Cell Types A.Prokaryote—NO nucleus; NO membrane-bound organelles ex: bacteria B.Eukaryote—Has a nucleus; has membrane-bound organelles ex: protists, fungi, plants, animals

IV. Differences Between Plant and Animal Cells A. Plant cells have cell walls. Animal cells do NOT. B. Plant cells have larger vacuoles than animal cells. C.Plant cells have chloroplasts. Animal cells do NOT. D. Lysosomes are found in animal cells—NOT plant cells.

V. Multicellular Organization Cells—tissues—organs—systems

Letter "e" This is the way the letter should have appeared under the microscope in the wet mount slide lab.

VI. Organelles/Cell Parts 1. Cell membrane (or plasma membrane) a. Structure: 2 layers of lipids with proteins b. Function: 1. boundary for the cell 2. selectively permeable—allows only certain things in or out

Plasma Membrane

2. Nucleus a. Structure: large; near center of cell; surrounded by nuclear membrane (envelope) b. Function: 1. contains DNA in the form of chromatin or chromosomes 2. controls cell activities 3. Cytoplasm (or cytosol) a. Structure: jelly-like material b. Function: site of most chemical reactions in cell

4. Nucleolus a. Structure: small, inside the nucleus b. Function: makes ribosomes (rRNA) 5. Ribosomes a. Structure: tiny, round bodies; NOT bound by a membrane b. Function: make protein

6. Endoplasmic reticulum 2 Kinds: rough—has ribosomes smooth—no ribosomes a. Structure: folded sacs that are connected to one another b. Function: transports substances within the cell

Endoplasmic Reticulum

Golgi body

7. Golgi Apparatus (complex or bodies) a. Structure: stacks of sacs—NOT connected b. Function: processes and packages protein 8. Mitochondria (has its own DNA) a. Structure: oval-shaped; two membranes— the inner one is folded (cristae) b. Function: supplies cell with energy (through aerobic respiration) cristae

Mitochondrion

9. Lysosomes “suicide sacs” (In animals; NOT in plants) a. Structure: small spheres b. Function: contain digestive enzymes; digest bacteria, worn-out cell parts, etc. 10. Vacuoles a. Structure: small spheres (animals); large (plants) b. Function: used for storage

Lysosome

Vacuole

11. Cell wall (NOT in animal cells) a. Structure: thick, rigid; surrounds cell membrane b. Function: supports and strengthens cell 12. Cilia (cilium-singular) a. Structure: short and hair-like b. Function: used for movement OR to help move substances past the cell

Cilia Cilia covering a Paramecium

Flagella Flagella on Giardia ←

Flagellum Structure

13. Flagella (flagellum-singular) a. Structure: long and whip-like b. Function: used for movement 14. Chloroplasts (a type of plastid) Plastids contain pigments. a. Structure: oval-shaped b. Function: site of photosynthesis; contains chlorophyll (a green pigment)

15. Microtubules (part of cytoskeleton) a. Structure: long, slender tubes b. Function: 1. give cell shape and support 2. form spindle fibers during cell division 16. Microfilaments (part of cytoskeleton) a. Structure: fine, thread-like b. Function: 1. help shape and support cell 2. cytoplasmic streaming in amoebas

Microtubules Cut-out from flagellum structure

Microfilaments

17. Centrioles (In animals; NOT in plants) a. Structure: two small cylinders usually found at right angle to each other b. Function: involved in cell division in animals

Centrioles