3A 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.
7English 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.
8Important 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.
9Micron (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
10Types 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
11TM =OLM x OL Computation for the size of specimen Where: TM = Total MagnificationOLM = Objective Lens MagnificationOL = Ocular Lens
12Types of Microscopes2. Stereomicroscope (Dissecting Microscope) – consists of two eyepieces and two objective lenses.- used for dissecting small specimens.Magnification = ranging from 4x to 50x
13Resolution 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
14Types 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
15Types 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
16Types of Electron Microscopes c. Scanning Tunneling Microscope (STM) – allows viewing of atoms on the surface of a solid.Magnification = over 1 million times
17OTHER SCIENTIFIC TOOLS Ultracentrifuge – a machine used to separate suspended particles in a mixture.
18OTHER SCIENTIFIC TOOLS 2. Chromatography – used in separating substances in a mixture.Types:Paper ChromatographyColumn Chromatography
19OTHER 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.
20OTHER SCIENTIFIC TOOLS 4. X-ray Diffraction – useful for analysis of protein crystals using X-rays of a single wavelength.
21OTHER 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.
22OTHER 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.