课件-国外大学细胞生物学课件-英文1bioy.ppt

W2011 D103 Cell Biology - lecture 1 ? Suetterlin and MacGregor - all rights reserved. * 1. Why do we study cell biology? 2. What can we see by microscopy? 3. What are model organisms? Lecture 1 Introduction to Cell Biology * Cells are the smallest subunit of every organism ORGANS TISSUES CELLS VERTEBRATES * Why should we study cell biology? Provides insight into the mechanism of how cells work We have to understand the details of a single cell in order to understand a complex, multi-cellular organism. Fascinating ? Essential for the understanding of human diseases and their treatments. * “The key to every biological problem must be sought in the cell, for every organism is, or at sometime has been, a cell.” Edmund Beecher (EB) Wilson Cell Biologist, 1925 * Approaches to understanding biology Cell Biology: ? Reveals size, shape and location of cellular components ? Provides insight into mechanism behind a process Biochemistry: Reveals molecular structure and chemistry of purified cell constituents Genetics: Reveals roles of healthy genes and the consequences of damaged genes Developmental Biology: Reveals changes in cells as they specialize * Comparing the size of biological objects * What can we see by light microscopy? * How can we see smaller structures??? Light microscope: Visible light serves as the source of illumination (wavelength of 700 to 400 nm) ? Light microscopy can resolve details that are at least 200 nm apart Limitation of microscopy Rule of thumb for the resolving power of a microcsope: 1/2 wavelength * Why? Electrons, which have a much shorter wavelength, serve as light source. Electron microscopy can resolve structures as small as 0.2 nm. * Light microscope Electron microscope Comparing the size of biological objects * Microscopy allows to determine how something looks (size, number) where something localizes Microscopy does NOT provide information about the function of a structure or protein the concentration of a protein the