biology unit c: cycling of matter in living systems chapter 1: developments in imaging technology
TRANSCRIPT
BiologyBiologyUnit C: Cycling of Matter in Unit C: Cycling of Matter in
Living SystemsLiving Systems
Chapter 1: Developments in Chapter 1: Developments in Imaging TechnologyImaging Technology
A Window to a New WorldA Window to a New World
Agenda:Agenda:- Introduction to MicroscopesIntroduction to Microscopes- Uses for MicroscopesUses for Microscopes- People involved in Scientific Discovery and People involved in Scientific Discovery and
Inventions/Improvements to Microscopes:Inventions/Improvements to Microscopes:- AristotleAristotle- Hans & Zacharias JensenHans & Zacharias Jensen- Robert HookeRobert Hooke- Antoni van LeeuwenhoekAntoni van Leeuwenhoek
- Types of MicroscopesTypes of Microscopes- Parts of the Compound Light MicroscopeParts of the Compound Light Microscope- Care and Use of the MicroscopeCare and Use of the Microscope
MicroscopesMicroscopes
What do we use What do we use Microscopes for?Microscopes for?– To see anything To see anything
that is difficult to that is difficult to see with the naked see with the naked eye (plant parts, eye (plant parts, animal parts)animal parts)
– http://en.wikipedia.org/wiki/Microscopehttp://en.wikipedia.org/wiki/Microscope
– Non-traditional Non-traditional uses:uses: Solving crimes: (hair Solving crimes: (hair
analysis, blood, other analysis, blood, other fluids)fluids)
Detecting crop diseases Detecting crop diseases and pathogensand pathogens
Detecting tiny defects in Detecting tiny defects in metal in bridges and metal in bridges and airplanesairplanes
Detection of diseases Detection of diseases like malaria and like malaria and TuberculosisTuberculosis
Use in Surgery Use in Surgery (laparoscopic)(laparoscopic)
A Brief HistoryA Brief History
So how did we come to use So how did we come to use Microscopes?Microscopes?– It began with Scientific Inquiry – Asking It began with Scientific Inquiry – Asking
questions about how things workquestions about how things work– Early GreeksEarly Greeks
Mostly philosophers – thinking out possible Mostly philosophers – thinking out possible answers to problems rather than testing ideasanswers to problems rather than testing ideas
Aristotle (384 to 322 B.C.)Aristotle (384 to 322 B.C.)::– Followed a pathway of accurate observations and record makingFollowed a pathway of accurate observations and record making– Set up a classification system based on his observationsSet up a classification system based on his observations– Reasoning and Interpretation followed the observationsReasoning and Interpretation followed the observations
A Brief HistoryA Brief History
Hans and Hans and Zacharias JanssenZacharias Janssen– Holland, ~1595Holland, ~1595– Father and son Dutch Father and son Dutch
lens makerslens makers– Invented the compound Invented the compound
microscope (2 lens microscope (2 lens system)system)
– Magnifying power ~ 20 Magnifying power ~ 20 XX
http://en.wikipedia.org/wiki/File:Zacharias.jpg
A Brief HistoryA Brief History
Robert Hooke (1635-Robert Hooke (1635-1703)1703)– Used a hand made Used a hand made
microscope with a 3-microscope with a 3-lens systemlens system
– Recorded observations Recorded observations of plants, animals, and of plants, animals, and non-living objectsnon-living objects
– Viewed cork and saw Viewed cork and saw many empty channels, many empty channels, which he called “cells” which he called “cells” because they looked because they looked like Monks’ cellslike Monks’ cells
http://en.wikipedia.org/wiki/Robert_Hooke
http://en.wikipedia.org/wiki/File:Hooke_Microscope-03000276-FIG-4.jpg
http://en.wikipedia.org/wiki/File:HookeFlea01.jpg
A Brief HistoryA Brief History Antoni van Antoni van
Leeuwenhoek (~1665)Leeuwenhoek (~1665)– Identified different Identified different
types of single celled types of single celled organisms such as organisms such as bacteria, sperm and bacteria, sperm and unicellular protozoaunicellular protozoa
– Highly skilled in Highly skilled in making small lenses, making small lenses, and was able to and was able to produce higher produce higher magnifications than magnifications than the compound the compound microscopes of the daymicroscopes of the day
http://en.wikipedia.org/wiki/File:Leeuwenhoek_Microscope.png
A Replica of van Leeuwenhoek’s Microscope
Microscopic section through 1 year old Ash tree wood
http://en.wikipedia.org/wiki/File:Leeuwenhoek_Eschenholz.jpg
MicroscopesMicroscopes
Units of Units of MeasurementMeasurementUnitUnit Equivalent Equivalent
MeasurementMeasurementUseful in ObservingUseful in Observing
Centimetre (cm)Centimetre (cm) 1/100 metre; 101/100 metre; 10-2-2 m m Visible objectsVisible objects
Millimetre (mm)Millimetre (mm) 1/10 centimetre; 101/10 centimetre; 10-3-3 mm
Large particles or cellsLarge particles or cells
Micrometre – also Micrometre – also known as the known as the MicronMicron ((µµm)m)
1/1000 millimetre; 101/1000 millimetre; 10-6-6 mm
Majority of cells and Majority of cells and their component partstheir component parts
Nanometre (nm)Nanometre (nm) 1/1000 micrometre, 1/1000 micrometre, 1010-9-9m m
Large molecules and Large molecules and most cell partsmost cell parts
Angstrom (Å)Angstrom (Å) 1/10 nanometre; 101/10 nanometre; 10--
1010mmMolecules and atomsMolecules and atoms
MicroscopesMicroscopes
Types of MicroscopesTypes of Microscopes– 4 basic types of microscopes (in two 4 basic types of microscopes (in two
categories):categories): Light Microscopes:Light Microscopes:
– Dissection microscopesDissection microscopes– Compound MicroscopesCompound Microscopes
Electron Microscopes:Electron Microscopes:– Scanning Electron MicroscopeScanning Electron Microscope– Transmission Electron MicroscopeTransmission Electron Microscope
Light MicroscopesLight Microscopes Use light focused on Use light focused on
the object to the object to illuminate itilluminate it
Dissection Dissection microscopemicroscope::– Image is 3-D, but it only Image is 3-D, but it only
has a low magnification, has a low magnification, so you cannot see so you cannot see individual cellsindividual cells
Compound Compound microscopemicroscope::– Image is 2-D, but the Image is 2-D, but the
magnification is magnification is powerful enough to see powerful enough to see individual cells (with a individual cells (with a low resolution)low resolution)
A thumb through a dissecting microscope
http://www.itg.uiuc.edu/exhibits/gallery/pages/image-26.htm
Human hair at 100x mag.
http://www.microscopeworld.com/MSWorld/microscope_images.aspx
Human hair at 400x mag.
http://www.microscopeworld.com/MSWorld/microscope_images.aspx
Electron MicroscopesElectron Microscopes Use a beam of electrons, Use a beam of electrons,
rather than light, to illuminate rather than light, to illuminate the object you are viewingthe object you are viewing
Scanning Electron Scanning Electron microscope (SEM):microscope (SEM):– High magnification and high High magnification and high
resolution, image is 3-Dresolution, image is 3-D– Objects are coated in gold Objects are coated in gold
then the electrons bounce off then the electrons bounce off the outside to give you a the outside to give you a black and white imageblack and white image
Transmission Electron Transmission Electron microscope (TEM):microscope (TEM):– Electron beams pass through Electron beams pass through
thin specimens of the object, thin specimens of the object, giving a 2-D image with high giving a 2-D image with high resolution at a high resolution at a high magnificationmagnification
http://www.arco-iris.com/George/microscopes/micro_fossil_02.jpg
http://www.itg.uiuc.edu/exhibits/gallery/pages/image-51.htm
Synapse from a rat’s visual cortex
Compound MicroscopeCompound Microscope
You will be using a You will be using a compound compound microscope for microscope for your labyour lab
You will need to You will need to know the different know the different parts of the parts of the microscope and microscope and how to use it safely how to use it safely and carefullyand carefully
http://www.yorkoptical.com.au/portals/0/StockImages/14001-049-I01.jpg
Compound MicroscopeCompound Microscope
http://www.yorkoptical.com.au/portals/0/StockImages/14001-049-I01.jpg
Ocular lens (eyepiece)
Body tube
Arm
Revolving nosepiece
Objective lenses
Stage
Stage clips
Light source
Course adjustment knob
Power switch
Base
Note: Fine adjustment knob and iris diaphragm do not appear on this diagram
Parts of the MicroscopeParts of the Microscope Eyepiece or Ocular Lens:Eyepiece or Ocular Lens:
– Has a lens that enlarges the image from the objective Has a lens that enlarges the image from the objective lens (usually 10X)lens (usually 10X)
Course Adjustment Knob:Course Adjustment Knob:– Brings the image into focus. Brings the image into focus. – Used only with the Used only with the low powerlow power objective lens objective lens
Fine Adjustment Knob:Fine Adjustment Knob:– Brings the image into focus with more detailBrings the image into focus with more detail– Used with the medium and high power objective lensesUsed with the medium and high power objective lenses
Arm:Arm:– Supports the microscopeSupports the microscope– Use to help carry the microscopeUse to help carry the microscope
Parts of the MicroscopeParts of the Microscope Revolving Nosepiece:Revolving Nosepiece:
– Rotating mount that holds many objective lensesRotating mount that holds many objective lenses Objective lenses:Objective lenses:
– Gathers light from a specimen and forms an inverted Gathers light from a specimen and forms an inverted imageimage
– Low = 4X magnificationLow = 4X magnification– Medium = 10X magnificationMedium = 10X magnification– High = 40X magnificationHigh = 40X magnification
Stage:Stage:– Supports the microscope slideSupports the microscope slide
Stage clips:Stage clips:– Holds the slide in placeHolds the slide in place
http://www.fotosearch.com/photos-images/microscope_2.html
Parts of the MicroscopeParts of the Microscope Iris Diaphragm:Iris Diaphragm:
– Controls the amount of light reaching the objectControls the amount of light reaching the object Light Source:Light Source:
– Sends light up through the object being viewedSends light up through the object being viewed– Also called “lamp” or “mirror”Also called “lamp” or “mirror”
Base:Base:– Supports the microscopeSupports the microscope– Also hold this when carrying the microscope (along with Also hold this when carrying the microscope (along with
arm)arm) Power Switch:Power Switch:
– Turns the light source on/offTurns the light source on/off– May or may not be present on all microscopesMay or may not be present on all microscopes
Care and Use (p. 5)Care and Use (p. 5) ReadRead the information the information beforebefore you start you start PracticePractice the skills you learn the skills you learn AskAsk questions if you are not sure! questions if you are not sure!
1. 1. AlwaysAlways use 2 hands to carry the microscope! use 2 hands to carry the microscope! In the upright In the upright position with one hand supporting the base, and one holding position with one hand supporting the base, and one holding the armthe arm
2. Do not touch the lens with anything2. Do not touch the lens with anything 3. Always check that the light switch is OFF 3. Always check that the light switch is OFF before you plug it before you plug it
inin 4. Always store your microscope with the stage 4. Always store your microscope with the stage loweredlowered and and
the revolving nosepiece at its the revolving nosepiece at its lowestlowest point point 5. Cover the microscope and return it to its storage place5. Cover the microscope and return it to its storage place 6. 6. YOUYOU are responsible for cleaning your equipment (including are responsible for cleaning your equipment (including
the glass slides) after use. the glass slides) after use. Use only lens paper to clean Use only lens paper to clean lenses.lenses.
7. Inform your teacher if your microscope does not work7. Inform your teacher if your microscope does not work
http://www.fotosearch.com/photos-images/microscope.html
Viewing Objects with the Viewing Objects with the Microscope (p. 5)Microscope (p. 5)
1. Check that the stage is 1. Check that the stage is at its lowest point at its lowest point and turn and turn the objective lens to the the objective lens to the lowest powerlowest power
2. Secure a prepared slide on the stage2. Secure a prepared slide on the stage 3. 3. While watching the stageWhile watching the stage raise it until the slide gets raise it until the slide gets
as close to the objective lens as it can as close to the objective lens as it can without touching itwithout touching it 4. Look in the ocular lens while you use the 4. Look in the ocular lens while you use the course focus course focus
to LOWER the stageto LOWER the stage until the object comes into view. until the object comes into view. Fine focus is used to get a sharper image. Adjust the iris Fine focus is used to get a sharper image. Adjust the iris diaphragm if necessarydiaphragm if necessary
5. Turn to the medium power lens. 5. Turn to the medium power lens. Only use the fine Only use the fine focus adjustment under medium and high powered focus adjustment under medium and high powered lenses!lenses!
6. 6. Lower the stage Lower the stage and return the objective lens to the and return the objective lens to the lowest power lowest power beforebefore removing the slide removing the slide
http://www.fotosearch.com/photos-images/microscope.html
A Look AheadA Look Ahead
Next Class:Next Class:– You will be using a microscope in pairs You will be using a microscope in pairs
in the laboratory for class.in the laboratory for class.– Bring your microscope handout, a Bring your microscope handout, a
pencil, and a ruler.pencil, and a ruler. It’s also not a bad idea to bring your C1 It’s also not a bad idea to bring your C1
booklet with the care and use instructions as booklet with the care and use instructions as well as the list of the parts of the well as the list of the parts of the microscopesmicroscopes