Microscops
Subdecks (2)
Cards (117)
- Microscopes are instruments that scientists use to study cells
- Development and use of microscopes was crucial in the development of cell theory
- Modern microscopy techniques have greatly advanced our understanding of the structure and function of cells
- Light Microscopes:
- Allow scientists to observe first structure in cells including:
- Nucleus
- Chloroplast
- Cytoplasm
- Vacuole
- Cell Wall
- Cell Membrane
- How it works:
- Beam of light passes through the specimen and a series of lens to magnify the specimen up to 1500x
- One lens is the objective lens and the other lens in the ocular (eyepiece) lens
- Staining Techniques:
- Development of specific dyes to stain cells allowed scientists to distinguish different structures of the cell more clearly under the light microscope
- Fluorescent Microscopes:
- Specimen is labelled with a fluorescent substance, e.g. stains to dyes, that attach to specific structure to be observed
- How it works:
- Specimen is illuminated with a high intensity light that causes the fluorescent structures to emit light
- Electron Microscope:
- Allowed scientists to observe the structure of cells in greater detail
- All previous structures from the light microscope can be seen providing increased knowledge of their structure and function
- Additional structures visible:
- Golgi Body
- Nucleolus
- Mitochondria
- Ribosomes
- ER
- Lysosomes
- How it works:
- Beam of electrons are transmitted through the specimen to produce a 2-D image up to 1,500,00x
- Scanning Electron Microscope:
- How it Works:
- Solid specimen is bombarded with a beam of electrons which causes secondary electrons to be emitted from the surface layers of the specimen to produce a 3-D image up to 1,500,00x
- Confocal Laser Scanning Microscope:
- Takes an image of the specimen allowing a computer program to construct a model
- How it works:
- Image of the specimen is taken at many different levels using laser beams
- Computer program is then used to reconstruct a 3-D image/model