3 A compound microscope used in 18th-century France A compound microscope used in 18th-century France. First developed in the late 16th century, compound microscopes use two or more sets of lenses to achieve high magnification.
7 English scientist Robert Hooke built this microscope in the 17th century and used it to conduct pioneering research. He discovered the cell structure of plants by observing a thin slice of cork under his microscope.
8 Important Tools in Biology Microscopes – is an instrument that uses lenses to produce an enlarged and focused image of a specimen.Two properties:1. Magnification – is the ratio between the image size and the object size.2. Resolution (Resolving power) – refers to the smallest degree of separation at which two objects are viewed as distinct from one another, rather than as a blurry, single image.
9 Micron (µ)- unit of measurement used in microscope study. Conversion of Units:1µ = m1µ = 0.001mmExamples:Range of Bacteria = 0.5 to 2µRange of some nerve cells = 1000µ
10 Types of Microscopes1. Compound Light Microscope – focuses and bends visible light through a specimen to produce a magnified image.*Magnification = up to 1500x*Resolution = 0.1 to 0.2µ
11 TM =OLM x OL Computation for the size of specimen Where: TM = Total MagnificationOLM = Objective Lens MagnificationOL = Ocular Lens
12 Types of Microscopes2. Stereomicroscope (Dissecting Microscope) – consists of two eyepieces and two objective lenses.- used for dissecting small specimens.Magnification = ranging from 4x to 50x
13 Resolution power = about 1,000 times Types of Microscopes3. Electron Microscope – uses a beam of electrons instead of light to create image.- the beam of electrons is focused using magnetic lenses.Resolution power = about 1,000 times
14 Types of Electron Microscopes Transmission Electron Microscope (TEM) – uses a magnetic field beam to focus a beam of electrons through a thin section of the specimen.Magnification = about 100,000 times
15 Types of Electron Microscopes b. Scanning Electron Microscope (SEM) – gives a surface view of a three-dimensional specimen by bouncing electrons off its surface.Magnification = about 10,000 times
16 Types of Electron Microscopes c. Scanning Tunneling Microscope (STM) – allows viewing of atoms on the surface of a solid.Magnification = over 1 million times
17 OTHER SCIENTIFIC TOOLS Ultracentrifuge – a machine used to separate suspended particles in a mixture.
18 OTHER SCIENTIFIC TOOLS 2. Chromatography – used in separating substances in a mixture.Types:Paper ChromatographyColumn Chromatography
19 OTHER SCIENTIFIC TOOLS 3. Electrophoresis – used to separate substances in a mixture according to how fast they move when subjected to an electric current.- commonly used to purify proteins based on their sizes and shapes.
20 OTHER SCIENTIFIC TOOLS 4. X-ray Diffraction – useful for analysis of protein crystals using X-rays of a single wavelength.
21 OTHER SCIENTIFIC TOOLS 5. Spectrophotometer – used to determine the amount of proteins or nucleic acid present in a solution.- measures the amount of light absorbed by the solution at specific wavelength.
22 OTHER SCIENTIFIC TOOLS 6. Computer – useful in storing vast amounts of information.- also used to organize data, make long and complex calculations and make graphs to summarize results.