tailieunhanh - Chapter 6- A Tour of the Cell
In a light microscope (LM), visible light passes through a specimen and then through glass lenses(co thau kinh), which magnify(phong dai) the image | Chapter 6 A Tour of the Cell Overview: The Fundamental Units of Life All organisms are made of cells The cell is the simplest collection of matter that can live Cell structure is correlated to cellular function All cells are related by their descent(nguon goc,dong doi, the he) from earlier cells Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings For the Discovery Video Cells, go to Animation and Video Files. Fig. 6-1 Figure How do cellular components cooperate to help the cell function? Concept : To study cells, biologists use microscopes and the tools of biochemistry Though usually too small to be seen by the unaided eye, cells can be complex Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Microscopy Scientists use microscopes to visualize cells too small to see with the naked eye In a light microscope (LM), visible light passes through a specimen and then through glass lenses(co thau kinh), which magnify(phong | Chapter 6 A Tour of the Cell Overview: The Fundamental Units of Life All organisms are made of cells The cell is the simplest collection of matter that can live Cell structure is correlated to cellular function All cells are related by their descent(nguon goc,dong doi, the he) from earlier cells Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings For the Discovery Video Cells, go to Animation and Video Files. Fig. 6-1 Figure How do cellular components cooperate to help the cell function? Concept : To study cells, biologists use microscopes and the tools of biochemistry Though usually too small to be seen by the unaided eye, cells can be complex Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Microscopy Scientists use microscopes to visualize cells too small to see with the naked eye In a light microscope (LM), visible light passes through a specimen and then through glass lenses(co thau kinh), which magnify(phong dai) the image Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings The quality of an image depends on Magnification, the ratio of an object’s image size to its real size Resolution, the measure of the clarity(trong sang,ro rang) of the image, or the minimum distance of two distinguishable points Contrast, visible differences in parts of the sample Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Fig. 6-2 10 m 1 m m 1 cm 1 mm 100 µm 10 µm 1 µm 100 nm 10 nm 1 nm nm Atoms Small molecules Lipids Proteins Ribosomes Viruses Smallest bacteria Mitochondrion Nucleus Most bacteria Most plant and animal cells Frog egg Chicken egg Length of some nerve and muscle cells Human height Unaided eye Light microscope Electron microscope Figure The size range of cells LMs can magnify effectively to about 1,000 times the size of the actual specimen Various techniques enhance(giam,ha xuong) contrast and enable cell components(thanh .
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