Unit C: Cycling of Matter in Living

Systems

Unit C: Cycling of Matter in Living

Systems

• Aristotle is known as “The Father of Biology.”

• He was one of the first Greek philosophers who used the Scientific Method of observing, recording, reasoning, and interpreting in attempt to explain the world around him.

3000 years ago: Egypt & Mesopotamia

• Glass – the material for lenses

Early 1200s: Roger Bacon

• Described how crystal lenses might improve vision of the elderly

Late 1200s: Salvino degli Amati (Italy)

• Made the first pair of spectacles

• Lenses were fashioned by craftsmen

• A new branch of physics, called optics, was born to explain the movement of light

1600s: Telescopes & Microscopes• 1595 Hans and Zacharias Janssen (Holland) invent

the first 2-lens compound light microscope• 1665 Robert Hooke (England) developed a 3-lens

system. – Hooke observed thin slices of cork and saw what he

called cells

• 1665 Antoni van Leeuwenhoek, an expert lens crafter was the first to reveal the microbial world– His daughter helped him make his microscopes– They were the first to see the movement of different

types of cells we now call protozoa, sperm, and bacteria

Microscope by Hans and Zacharias Janssen

Figure C1.3 Hooke’s Mircroscope

• As lens technology improved over the years, the world’s knowledge of the microscopic world increased, allowing us to solve many problems

Red Blood Cells Human Immunodeficiency Virus (HIV)

E. Coli bacteria cluser

• A MICROSCOPE is an instrument with a lens or system of lenses for magnifying specimens.

• In order to use a microscope you must be familiar with the following:

1. Microscope Structures & Functions2. Microscope Handling Protocol3. Calculating Magnification4. Unit Conversion5. Field of View

1.Eye Piece or Ocular Lens.

2.Coarse Focus Adjustment

3.Arm

4.Stage Clip

5.Fine Focus Adjustment

6.Base

7.Lamp

8.Diaphragm

9.Stage

10.Objective Lenses

11.Revolving Nosepiece

12.Body Tube

Handling A Microscope

1. Always carry the microscope in an upright position with two hands: one on the base, the other on the arm.

2. Use only lens paper to clean lenses.3. Make sure the power switch is off

before you plug it in.4. Never allow the lens to touch the slide.5. Never attempt to repair the

microscope yourself.

6. Use stage clips to hold the slide steady.

7. Always start to focus on the low-power objective lens first.

8. Use the coarse focus first. 9. Never use the coarse focus on the

high-power objective lens.10.When you are finished:

a) Rotate to the low-power objective lensb) Remove the slidec) Turn the microscope offd) Put the dust cover one) Remove the power cord from the socket by the

plug.

Calculating Magnification

• The MAGNIFICATION tells the reader how much larger (or smaller) the picture is than the real size of the item

• In order to calculate the magnification of a system use the following formula:

lensocularlensobjectiveionMagnificat

What is the magnification if the following combinations of lenses are used?

pg. 244 Calculating Magnification

b) A 100X high-power objective lens and a 10X ocular lens?

a) A 2.5X low-power objective lens and a 10X ocular lens?

25X

1000X

Unit Conversion

Line Master 1: Units of Measurement

Unit Equivalent Measurement

Centimetre (cm) 1/100 metre; 10–2 m

Millimetre (mm) 1/10 centimetre; 10–3 m

Micrometre—also known as the Micron (μm)

1/1000 millimetre; 10–6 m

Nanometre (nm) 1/1000 micrometre; 10–9 m

Angstrom (Å) 1/10 nanometre; 10–10 m

Complete the following table.

Unit Conversion

40cm ______μm

______ cm 1.6 nm

400 A ______ mm

Field of View

• The FIELD OF VIEW is the entire area that you see when you look through the microscope.

• Activity: Look at your partner through a paper towel roll. Now, get your partner to walk closer to you. Do you see more or less of your partner? Does your partner appear larger or smaller when he or she is closer to you? The same idea applies to magnification:

• Magnification increases the size of what you see BUT decreases the amount of the object in view

• Since the field of view decreases in size in direct proportion to the increase of the magnification, we can calculate the size of the other fields of view.

• For example: If the field of view is 4000μ at 40X, it will be 10 times smaller at 400X, or 400μ in size.

Complete the following table:

Calculating Field of View

Lens Magnification

Field of view (mm)

Field of view (μm)

40 4

100 1.6 1600

400

4000

4000.4

Read pp. 242-246Check & Reflect pg. 246

#1-8Line Masters 1 & 2