BIOL340 QUIZ 1 EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS VERIFIED

BIOL340 QUIZ 1 EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS VERIFIED what is light microscopy - how does it work visible light passes through specimen, glass lenses refract the light to magnify the specimen what is the resolution limit of light microscopy around 300 nm name the different types of light microscopy Brightfield (unstained), Brightfield (stained), Fluorescence, Phase contrast, Differential interference contrast, Confocal what is brightfield; unstained vs stained unstained: light passes through specimen, if it doesnt have natural pigment, there is no contrast stained: Staining with various dyes enhances contrast, but needs to be preserved what is fluorescence microscopy Fluorescent substances absorb ultraviolet radiation and emit visible light. The fluorescing molecules may occur naturally but more often are made by tagging the molecules of interest with fluorescent dyes or antibodies what is Transmission Electron Microscopy focuses a beam of electrons through the specimen - resolution = around 2 nm what is Scanning Electron Microscopy Electron beam scans the surface of the sample which is coated with a thin layer of gold - this excites electrons on the surface which are detected - used largely to examine the surfaces of objects What is the Extracellular Matrix its comprised of a 3D meshwork of interconnecting macromolecules with binding sites for each other and for receptors what are the main structural forms of ECMs basal lamina aka basement membrane (tissure interfaces) and connective tissue (bone, cornea, tendons) define basement membrane its a continuous sheet, surrounding muscle and fat cells. underlies epithelia and endothelia what are the main functions of basement membrane mechanical support, separates adjacent tissues and organs what are the main functions of connective tissue determines the physical properties of a tissue name the 3 classes of molecules in the ECM 1. Structural proteins (collagens and elastins) 2. protein-polysaccharide complexes 3. adhesive glycoproteins (fibronectin) EXAMPLE: Give an example of a specific basement membrane, describe its structure and the functional role it performs in that location An example of the basement membrane, or otherwise known as the basal lamina, is shown in the trachea. It surrounds the muscle and fat cells and underlies the epithelia and endothelia. The functions of this include mechanical support, separating adjacent tissues and organs, while still permitting cell migration. EXAMPLE: Name 3 classes of extracellular matrix components, give one example of each and briefly comment on their functions structural proteins = collagens and elastins (provide tensile strength, regulate cell adhesion) protein-polysaccharide complexes = proteoglycans (providing resilience, viscoelasticity, and a cushioned environment) adhesive glycoproteins = fibronectin (acts as a key player of the communication between the intra and the extracellular environment)