Microscopes: Staining and Electron Microscope Essay Example
1. What are the advantages and disadvantages of the different types of light and electron microscopes discussed in Chapter 3 that are used to study microorganisms? Focus your response in terms of the following parameters
The disadvantage of using a light microscope is its inability to magnify a specimen as great as an electron microscope. An electron microscope can magnify up to 500,000 times, whereas, a light microscope can only magnify an object up to 2000 times.
The resolving power or resolving ability is the ability to distinguish between two points on an image, for example, the amount of detail. The resolution distinguishes between fine detail & structure of a sample. The wavelength of light is much larger than the wavelength of electrons, therefore, making the resolution of the light microscope a lot lower.
The sample preparation for a light microscope is a lot simpler & easier when compared to an electron microscope. The preparation of a sample for an electron microscope can be lengthy & complex. For electron microscopes it is often necessary to coat the specimen with a very thin layer of metal, for example gold. The metal is able to reflect the electrons.
2. What type of microscope would you use to investigate each of the following scenarios and why
To determine the relative sizes of two eukaryotic cells I would use a light microscope. Light microscopes can magnify enough to see the cell walls, therefore, this type a microscope can be used the compare sizes.
To determine how many bacteria are dying after a chemical treatment I would also use a light microscope. Light microscopes can examine live samples, therefore, if you need to determine how many bacteria have died after a chemical treatment I would use a light microscope to compare live & dead bacteria.
To determine where in a eukaryotic cell a particular protein is localized I would use an electron microscope. Electron microscopes can see fine detail & structure because it has a
The disadvantage of using a light microscope is its inability to magnify a specimen as great as an electron microscope. An electron microscope can magnify up to 500,000 times, whereas, a light microscope can only magnify an object up to 2000 times.
The resolving power or resolving ability is the ability to distinguish between two points on an image, for example, the amount of detail. The resolution distinguishes between fine detail & structure of a sample. The wavelength of light is much larger than the wavelength of electrons, therefore, making the resolution of the light microscope a lot lower.
The sample preparation for a light microscope is a lot simpler & easier when compared to an electron microscope. The preparation of a sample for an electron microscope can be lengthy & complex. For electron microscopes it is often necessary to coat the specimen with a very thin layer of metal, for example gold. The metal is able to reflect the electrons.
2. What type of microscope would you use to investigate each of the following scenarios and why
To determine the relative sizes of two eukaryotic cells I would use a light microscope. Light microscopes can magnify enough to see the cell walls, therefore, this type a microscope can be used the compare sizes.
To determine how many bacteria are dying after a chemical treatment I would also use a light microscope. Light microscopes can examine live samples, therefore, if you need to determine how many bacteria have died after a chemical treatment I would use a light microscope to compare live & dead bacteria.
To determine where in a eukaryotic cell a particular protein is localized I would use an electron microscope. Electron microscopes can see fine detail & structure because it has a