MICROSCOPY AND CELLS BIO 171 WEEK 3

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1 MICROSCOPY AND CELLS BIO 171 WEEK 3

2 MICROSCOPY THE COMPOUND LIGHT MICROSCOPE System of lenses arranged to produce an enlarged, focusable image of a specimen.

3 MICROSCOPY THE MICROSCOPE Illuminating System Light source Condenser lens Condenser lens Light source

4 MICROSCOPY THE MICROSCOPE Ocular lenses Imaging System Objective lenses Ocular lenses Body tube Objective lens Body tube

5 MICROSCOPY THE MICROSCOPE Other parts Stage Stage clips Arm Base Course adjustment knob Fine adjustment knob Arm Stage Base

6 Course Adjustment Knob Stage Fine Adjustment Knob

7 MICROSCOPY RULES AND USE Always carry upright with one hand under the base and the other around the arm. Only clean lenses with lens paper Always start on low-power objective. If shifting to a higher power objective, rotate carefully. Always use fine adjustment knob when using a higher power objective

8 USING A COMPOUND LIGHT MICROSCOPE 1) Ensure that lowest-power objective is in place. 2) Place specimen on the stage. 3) Adjust slide so that the area of interest is in view. 4) Use the course adjustment knob to focus on the specimen. 5) Slowly rotate the high-power objective into place, making sure that the lens does not touch the slide. 6) Use the FINE ADJUSTMENT KNOB ONLY to further refine your focus.

9 ACTIVITIES - MICROSCOPY 3.1 Using a compound microscope 3.2 Magnification 3.3 Field of view 3.4 Depth of field 3.5 Preparing a Wet Mount

10 CELL THEORY All living organisms are composed of cells The cell is the basic unit of life Cells arise from pre-existing cells Cells contain hereditary information which is passed from cell to cell during cell division Scientific Theory: Explanation of some aspect of the natural world that has been substantiated through repeated experiments or testing. Examples: Atomic theory, Germ theory, Theory of Evolution, Theory of Homeostasis, Theory of Gravity, Theory of Molecular Bonds

11 INTRO CYTOLOGY REVIEW Prokaryotes

12 INTRO CYTOLOGY REVIEW PROKARYOTES Prokaryote = before nucleus No nucleus or membrane-bound organelles Regions of concentrated DNA Nucleoid Ribosomes particles involved in protein synthesis Flagella used for movement Pili attach to surfaces or exchange genetic material

ENDOSYMBIOTIC THEORY Prokaryotic organism is engulfed or parasitizes early eukaryote Mitochondria consume oxygen to extract energy (ATP) from glucose, produce carbon dioxide and water.

13 ENDOSYMBIOTIC THEORY Prokaryotic organism is engulfed or parasitizes early eukaryote Mitochondria consume oxygen to extract energy (ATP) from glucose, produce carbon dioxide and water. Chloroplasts consume water and carbon dioxide; capture energy from light, transforms light energy into chemical energy (glucose) and releases oxygen. Both mitochondria and chloroplasts have their own DNA.

14 INTRO CYTOLOGY REVIEW EUKARYOTES See Table 4.1 for differences between cell types

15 PLANT CELLS Elodea slide Onion

16 ACTIVITIES Chapter 3 - Microscopy 3.1 Using a compound microscope 3.2 Determining magnification 3.3 Alternate Procedure Field of view 3.4 Determine depth of field 3.5 Prepare wet mount of pond water 3.6 Look through dissecting scope Chapter 4 The Cell 4.1 Cyanobacteria (Merismopedia, Nostoc, and Oscillatoria) 4.2 Yogurt 4.3 Elodea Prepared slides 4.5 Stained Onion Cells Stain with Iodine (IKI) 4.7 Examine amyloplasts (in potato) 4.9 Examine amoeba 4.10 Examine Paramecium 4.11 Examine Spirogyra 4.12 Examine Unknown/Pond Water

photosynthesis Surrounded by mucilaginous sheath

17 CYANOBACTERIA Sometimes called blue-green algae Large prokaryotes with chlorophyll and other pigments for photosynthesis Surrounded by mucilaginous sheath Contributed to early oxygenation of ancient earth s atmosphere

18 BACTERIA Yogurt Lactobacillus Gram positive bacteria Converts lactose into lactic acid (milk yogurt) How does the size of Lactobacillus compare to the Cyanobacteria?

19 ELODEA Look for chloroplasts, nucleus, cell wall, central vacuole.

20 ONION CELLS Stain with IKI (Iodine) Compare stained VS unstained onion cells

21 AMYLOPLASTS Plastids that store starch Stain potato with iodine

22 SPIROGYRA Filamentous green alga Named for spiral arrangement of chloroplasts.

23 ACTIVITIES Chapter 3 - Microscopy 3.1 Using a compound microscope 3.2 Determining magnification 3.3 Alternate Procedure Field of view 3.4 Determine depth of field 3.5 Prepare wet mount of pond water 3.6 Look through dissecting scope Chapter 4 The Cell 4.1 Cyanobacteria (Merismopedia, Nostoc, and Oscillatoria) 4.2 Yogurt 4.3 Elodea Prepared slides 4.5 Stained Onion Cells Stain with Iodine (IKI) 4.7 Examine amyloplasts (in potato) 4.9 Examine amoeba (prepared slide) 4.10 Examine Paramecium (prepared slide) 4.11 Examine Spirogyra 4.12 Examine Unknown/Pond Water Answer questions in lab manual Dispose of pipettes in BIOWASTE Dispose of used slides in can on desk

Microscope History Robert Hooke

1 Microscope History Robert Hooke First described cells in 1665. He viewed thin slices of cork and compared the boxy partitions he observed to the cells (small rooms) in a monastery. (1635 1702) 2 Microscope