Cells
This presentation is the property of its rightful owner.
Sponsored Links
1 / 35

Cells PowerPoint PPT Presentation


  • 77 Views
  • Uploaded on
  • Presentation posted in: General

Cells. Organelles. CELL. The basic unit of structure & function in living organisms. Anton Van Leeuwenhoek. 1632-1723 Was a merchant that ground up glass to make lenses. Invented microscope Made over 500 in his lifetime 1 st person to examine bacteria.

Download Presentation

Cells

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Cells

Cells

Organelles


Cells

CELL

  • The basic unit of structure & function in living organisms


Anton van leeuwenhoek

Anton Van Leeuwenhoek

1632-1723

Was a merchant that ground up glass to make lenses

  • Invented microscope

  • Made over 500 in his lifetime

  • 1st person to examine bacteria


Van leeuwenhoek s sketches of a nerve

Van Leeuwenhoek’s sketches of a nerve


Robert hooke

Robert Hooke

  • 1635-1702

  • Used Van Leeuwenhoek’s microscopes

  • Named cells after looking at cork


Robert hooke s cork

Robert Hooke’s Cork


Robert brown

Robert Brown

  • 1773-1858

  • Discovered the nucleus in plant cells (1833)


Matthias schleiden

Matthias Schleiden

  • 1804-1881

  • Discovered all plants are made up of cells

    (1838)


Theodor schwann

Theodor Schwann

  • 1810-1882

  • Discovered that all animals are made up of cells(1839)


Rudolph virchow

Rudolph Virchow

  • 1821-1902

  • Proposed that all cells come from pre-existing cells (1855)


The cell theory

The Cell Theory

The cell theory states:

  • All living things are composed of cells

    B. Cells are the basic units of structure & function in living things

    C. All cells come from preexisting cells


Janet plowe

Janet Plowe

  • Demonstrated that the cell membrane is a physical structure (1931)


Lynn margoulis

Lynn Margoulis

  • Proposed that certain organelles were once free-living organisms themselves (1970)


Cells

Parts of Microscope

Nosepiece

Ocular

High Power Objective

Arm

Low Power Objective

Scanning Power Objective

Stage

Stage Clips

Course Focus

Fine Focus

Diaphragm

Base

Light (illumination)


Cells

Compound light Microscope Parts & Fxn’s

  • Occular – viewing eyepiece

  • Coarse adjustment – Rough focus

  • Fine adjustment – Fine focus

  • High power objective (400X)

  • Low objective (100X)

  • Scanning objective (40X)


Cells

Compound Light Microscope Parts & Fxn’s

  • Stage – holds slide up against stage clips

  • Stage clips – holds slide down on stage

  • Diaphragm – controls amount of light entering slide

  • Lamp – light source

This is an air bubble

under the microscope!!!


Cells

Power of magnification

  • The relative enlargement of the specimen when seen through the microscope.

  • The power of magnification can be calculated by multiplying the power of the eye piece lens by the power of the objective lens.


Cells

Inversion

  • The reversal of the specimen image by the microscope lenses.

  • A specimen that appears upside down when being viewed is actually right-side up on the slide.

  • Moving the specimen to the right causes its image to move to the left likewise, moving it down causes it to move upward.


Cells

Working distance

  • The distance between the front of the objective and the top of the cover glass on the slide.

  • The higher the magnification the smaller the working distance.

  • DO NOT USE THE COARSE ADJUSTMENT UNDER HIGH POWER!!!


Cells

Resolution

(Resolving Power)

  • The shortest distance between two points or lines at which they are seen as two, rather than a single blur.


Cells

Depth of focus

  • The thickness of a specimen which may be seen in focus at one time.


Cells

Objectives

  • Our microscopes have three objectives mounted on a revolving device known as a nosepiece.

  • Engraved on the objective is its power of magnification.

  • The longer the objective the more power of magnification.


Cells

Diaphragm

  • A device under the stage of a microscope that can regulate the amount of light reaching a specimen.


Cells

Power of Magnification

  • Definition - The relative enlargement of the specimen when seen through the microscope.

  • Power of magnification = (Power of the eyepiece lens) X (Power of the objective lens)


Cells

Rules for Handling the Microscope

  • Always carry the microscope with one hand under the base and the other grasping the arm.

  • Keep both eyes open when looking through the eyepiece.

  • Keep the stage clean and dry.

  • Do not remove parts of the microscope.

  • Use only lens paper when cleaning lenses.


Cells

Rules for Handling the Microscope

  • Always begin focusing with the lowest power objective.

  • Always look from the side when changes lenses

  • After completing your work, place the microscope on the lowest power objective.

  • Always return the microscope where you found it & as you found it


Modern microscopes

Modern Microscopes

Electron microscopes – capable of revealing details as much as 1000 times smaller than those visible in light microscopes. (Two types -TEM & SEM)

TEM – can explore cell structure and large protein molecules.

Downside – the specimens have to be sliced thinly


T e m

T.E.M.


Transmission electron microscopy t e m

Transmission Electron Microscopy T.E.M.


Modern microscopes1

Modern Microscopes

S.E.M. – Scanning electron microscopes –

specimens do not have to be cut thinly – a beam of electrons scans over the specimen.


S e m

S.E.M.


S e m magnification

S.E.M. Magnification


Prokaryotic eukaryotic cells

Prokaryotic & Eukaryotic Cells


  • Login