Studying Cells with Microscopy

Study Notes

The cell is the basic unit of life, but it is not visible to the naked eye and its structure can only be seen under a microscope.

Microscopes produce a magnified image of an object, allowing cells to be studied.
A simple convex glass lens can act as a magnifying glass, but it is more effective when used in pairs in a compound light microscope.
The resolution of a light microscope is about 0.2 µm, meaning that two objects must be at least 0.2 µm apart to be seen as separate.
Electron microscopes use beams of electrons with shorter wavelengths, allowing them to distinguish between two objects only 0.1 nm apart.

The magnification of an object is how many times bigger the image is compared to the object.
Magnification can be calculated using the formula: magnification = size of image / size of real object.
When calculating magnification, it is essential to ensure that the units of length are the same for both the object and the image.
The size of a real object can be calculated using the formula: size of real object = size of image / magnification.

The resolution of a microscope is the minimum distance apart that two objects can be in order for them to appear as separate items.
The resolving power depends on the wavelength or form of radiation used.
Increasing the magnification increases the size of an image, but does not always increase the resolution.
Every microscope has a limit of resolution, beyond which increasing the magnification will not reveal more detail but will only make the image more blurred.

Cell fractionation is the process of breaking up cells and separating out the different organelles they contain.
The process involves placing the tissue in a cold, buffered solution of the same water potential as the tissue.
Cell fractionation is necessary to study the structure and function of the various organelles that make up cells.

The cell is the basic unit of life, but it is not visible to the naked eye and its structure can only be seen under a microscope.

Microscopes produce a magnified image of an object, allowing cells to be studied.
A simple convex glass lens can act as a magnifying glass, but it is more effective when used in pairs in a compound light microscope.
The resolution of a light microscope is about 0.2 µm, meaning that two objects must be at least 0.2 µm apart to be seen as separate.
Electron microscopes use beams of electrons with shorter wavelengths, allowing them to distinguish between two objects only 0.1 nm apart.

The magnification of an object is how many times bigger the image is compared to the object.
Magnification can be calculated using the formula: magnification = size of image / size of real object.
When calculating magnification, it is essential to ensure that the units of length are the same for both the object and the image.
The size of a real object can be calculated using the formula: size of real object = size of image / magnification.

The resolution of a microscope is the minimum distance apart that two objects can be in order for them to appear as separate items.
The resolving power depends on the wavelength or form of radiation used.
Increasing the magnification increases the size of an image, but does not always increase the resolution.
Every microscope has a limit of resolution, beyond which increasing the magnification will not reveal more detail but will only make the image more blurred.

Cell fractionation is the process of breaking up cells and separating out the different organelles they contain.
The process involves placing the tissue in a cold, buffered solution of the same water potential as the tissue.
Cell fractionation is necessary to study the structure and function of the various organelles that make up cells.