MIC 102 EXAM I STUDY QUESTIONS with correct answers

Light Microscopy CORRECT ANSWER Used alongside differential staining i. Gram Staining: identifies gram (+) or gram (-) ii. Fluorescent stains: used to study molecule interaction/aggregation in certain tissue, cell, etc. 1. GFP used to study protein localization Cryo-electron microscopy CORRECT ANSWER Used to visualize objects (e.g. individual atoms) and finer structural cellular details much smaller than those resolved optically Cryo-electron tomography CORRECT ANSWER Creates 3D visual imaging of cells, objects, structures studied in above. Outline the steps in the Gram stain and explain how the cell structure of gram-negative and gram-positive cells leads to a given Gram stain result. CORRECT ANSWER 1.Heat fix bacteria: kills bacteria and makes it more receptive to stain 2.Primary stain w/ crystal violet 3.Rinse w/ DI H20 4.Stain w/ iodine (mordant; helps crystal violet bind) 5.Rinse w/ DI H20 6.Decolorize w/ ethanol, acetone 7.Rinse w/ DI H20 8.Counter stain w/ safranin 9.Rinse w/ DI H20