Fixation means prevention of degeneration of cells and tissue by the autolytic enzymes present in the cells and preservation of cells as close as possible to the living state (Manual for Cytology‚ 2005). Specifically in cytology‚ the purpose of fixation is to Maintain‚ as closely as possible‚ the cytomorphologic characteristics and diagnostically essential cytochemical elements of the cell. (Yoshida‚ 2004) Deactivate autolytic enzymes Replace cellular water Facilitate diffusion of dyes across
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used to differentiate the three classes of alcohols. Tertiary alcohol turns cloudy or appears in two layers almost immediately‚ secondary alcohol reacts within 5 to 10 minutes whereas primary alcohol reacts very slowly. Alcohol can be oxidised to aldehyde‚ ketone or carboxylic acid. The product formed depends on the class of alcohol used. Various oxidising agents such as KMnO₄‚ Na₂Cr₂O₇ and H₂CrO₄ can be used. The reaction between alcohols and carboxylic acids will produce esters. Apparatus: Stopper
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Science Project : Sublimation of Dry Ice in Water Christopher Drake Dana Smith Panut Panusiri Ehsan Subhani Period 4 Honors Chemistry Mr. Mattson Table of Contents Purpose 3 Experimental Questions 4 Preliminary Research
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Pheromones Pheromones are chemical signals that are used among insects or animals to communicate and to convey messages among species of the same colony. The messages that pheromones convey have to do with behavior and physiological functions. In other words‚ pheromones are hormones that are excreted and act outside of the body. The word “Pheromones” comes from Greek which means “carrier of excitation”. The purpose why animals and insects excrete these hormones is: to convey the message that
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Sodium borohydride Reduction of Benzil Introduction: The Purpose of this experiment is for the students to learn how to use sodium borohydride to reduce benzil to its secondary alcohol product via reduction reaction. This two-step reaction reduces aldehydes by hydrides to primary alcohols‚ and ketones to secondary alcohols. In order for the reaction to occur and to better control the stereochemistry and yield of the product‚ the metal hydride nucleophile of the reducing agents such as LiH‚ LiAlH4‚ or
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STERILIZATION AND DISINFECTION Definitions Bacteriostatic Agent: An agent that inhibits the growth of bacteria‚ but does not necessarily kill them. Bactericide: An agent that kills bacteria. Most do not kill Endospores. Sporicide: An agent that kills spores. Definition STERILIZATION The process of freeing an article from microorganisms including their spores. By definition‚ it effects a reduction in the number of microorganisms (more than 99.9999% are killed). Methods
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polysaccharides. They are the most important source of energy for most organisms. Polysaccharides change color in the presence of iodine solution: Glycogen gives a red-brown color and starch a dark blue–violet color. While simple sugars‚ having an aldehyde group‚ or a ketone group act as reducing agents in the presence of Benedict’s reagent producing a range of colors from green to brown depending on the degree of reduction they exhibit. In a solution of sufficiently high pH‚ sugars can reduce weak
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classic‚ both contemporary and unusual‚ remains the absolute benchmark of feminine fragrances‚ entrancing‚ elegant and always modern. 3” N°5 has different smell at different stages: • Top notes: Neroli from Grasse‚ Ylang-Ylang from the Comoros‚ Aldehydes. • Middle notes: Grasse Jasmine‚ May Rose. • Base notes: Sandalwood note‚ Vetiver from Réunion‚ Vanilla from Réunion. Nowadays‚ N°5 still very popular in the world because of it stills the top seller in Europe5 and won FiFi award in 2003 and
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Practical 2 Reaction of alkane‚ alkene & alkyne Title: Reaction of Saturated and Unsaturated Hydrocarbons Objective: To carry out chemical test to differentiate an alkane and an alkene. Apparatus: dropper‚ test tube‚ hot plate Chemical reagents: bromine‚ toluene‚ cyclohexane‚ cyclohexene‚ acidified KMnO4‚ dichloromethane Method A. Bromine test 1.6 clean and dry test tube were taken and were labelled them A until F 2.1ml of dichloromethane were placed into each test tube 3.1 ml of
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that exist which is why water has it’s unique qualities like high surface tension (refer to pg. 15 in txtbook if confused) Hydrophobic Functional Groups: Functional Group Name of Compound Formula Hydroxyl Alcohols R – OH Carbonyl Aldehydes Keytones R – C=O (end) R – C=O (middle) Carboxyl Carboxylic acids R – C=O \ OH Amino Amines Amides R – N – H \ H R – C=O \NH2 Sulfhydryl Thiols R – SH Phosphate Organic phosphates (double bond
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