Investigating the structure of a cell 0.0 / 5 ? BiologyPractical applications of biologyASAQA Created by: Hannah CarlingCreated on: 21-12-13 15:46 What is Magnification? How many times bigger the image is when compared to the object 1 of 13 What is the magnification equation? Magnification= size of image / size of object 2 of 13 What is Resolution? The minimum distance apart that two objects can be in order for them to be seen as seperate items 3 of 13 What is Cell Fractionation? The process where cells are broken down and the different organelles they contain are seperated out 4 of 13 Why is the cell tissue placed in a cold solution? To reduce enzyme activity that might break down the organelles 5 of 13 Why is the cell tissue placed in a isotonic solution? To prevent organelles bursting or shrinking as a result of osmosis 6 of 13 Why is the cell tissue placed in a buffered solution? To help maintain a constant pH 7 of 13 What happens during Homogenation? Cells are broken up by a homogeniser, the organelles from the cell are released and the resulting fluid is filtered to remove any complete cells 8 of 13 What is Ultracentrifugation? The process by which fragments is filtered in the homogenate and seperated by an ultracentrifuge. 9 of 13 Why do light microscopes have a poor resolution? They have a long wavelength 10 of 13 Why is the electron microscope better than the light microscope? They have a very short wavelength and they use a negatively charged beam of electrons 11 of 13 What are the issues with viewing specimens under the TEM? The specimen must be kept in a vaccum, specimens must be stained and they must be thin. 12 of 13 How does the SEM produce an image? The electrons are scattered across the specimen and the pattern of the scattering, depends on the specimens surface 13 of 13
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