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.11.Why do we study cell biology?2.What can we see by microscopy?3.What are model organisms?Lecture 1 Introduction to Cell BiologyW2011 D103 Cell Biology-lecture 1 Suetterlin and MacGregor-all rights reserved.2Cells are the smallest subunit of every organism ORGANSTISSUESCELLSVERTEBRATESW2011 D103 Cell Biology-lecture 1 Suetterlin and MacGregor-all rights reserved.3Why 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.W2011 D103 Cell Biology-lecture 1 Suetterlin and MacGregor-all rights reserved.4“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)WilsonCell Biologist,1925W2011 D103 Cell Biology-lecture 1 Suetterlin and MacGregor-all rights reserved.5Approaches to understanding biologyCell Biology:Reveals size,shape and location of cellular components Provides insight into mechanism behind a processBiochemistry:Reveals molecular structure and chemistry of purified cell constituentsGenetics:Reveals roles of healthy genes and the consequences of damaged genesDevelopmental Biology:Reveals changes in cells as they specializeW2011 D103 Cell Biology-lecture 1 Suetterlin and MacGregor-all rights reserved.6Comparing the size of biological objectsW2011 D103 Cell Biology-lecture 1 Suetterlin and MacGregor-all rights reserved.7What can we see by light microscopy?W2011 D103 Cell Biology-lecture 1 Suetterlin and MacGregor-all rights reserved.8How 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 apartLimitation of microscopyRule of thumb for the resolving power of a microcsope:1/2 wavelengthW2011 D103 Cell Biology-lecture 1 Suetterlin and MacGregor-all rights reserved.9Why?Electrons,which have a much shorter wavelength,serve as light source.Electron microscopy can resolve structures as small as 0.2 nm.W2011 D103 Cell Biology-lecture 1 Suetterlin and MacGregor-all rights reserved.10Light microscopeElectron microscopeComparing the size of biological objectsW2011 D103 Cell Biology-lecture 1 Suetterlin and MacGregor-all rights reserved.11Microscopy allows to determine how something looks(size,number)where something localizesMicroscopy does NOT provide information about the function of a structure or protein the concentration of a protein the mechanism of how a process works Biochemical approachesWhich kind of information can be obtained by microscopy?W2011 D103 Cell Biology-lecture 1 Suetterlin and MacGregor-all rights reserved.12Simple system to study a biological questionExtrapolation of results to higher organismsAvailability of genetics3 types of systems:prokaryotic cellsingle cell eukaryotemulticellular organisms Model systemsW2011 D103 Cell Biology-lecture 1 Suetterlin and MacGregor-all rights reserved.YeastFruit flywormmouse5800 genes13000 genes19000 genes30000 genesHaploid,mutants and deletions can easily be generated,Great for genetics and for screensDiploidGenetics,screens for componentsDiploidGenetics,screens for componentsDiploid.gene deletion mutants and transgenic animals can be generated Genetics are possible,Easy,cheap to grow,Fast doubling timeRelatively easy and cheap to growRelatively easy and cheap to growNot so easy anymore!Basic cell biological and genetic questionsDevelopment from single cell to multicellular organism,cell biologyprecise timing of development from single cell to adult with 959 cells,cell biologyDevelopment,immunology,mammalian genetics and cell biologyHow to choose a model systemW2011 D103 Cell Biology-lecture 1 Suetterlin and MacGregor-all rights reserved.14Summary of concepts,lecture 1Cells are the smallest unit of any organism.Cells vary in size from about 1 m(bacterium to about 200 m(oocyte).The resolving power of a microscope depends on the source of illumination.The rule of thumb for the resolving power is:1/2 wavelength.Biological model system:the simplest possible organism that allows a scientist to address a particular question The choice of the model system depends on the particular question of research.