Lab Homework for 1-3

Lab Homework 1) which display below signifies biohazard? answer: b 2) flammable materials, like alcohol, should never be dispensed or used near answer: an open flame 3) if a laboratory fire erupts, immediately answer: notify your instructor 4) approved eye protection devices (such as goggles) are worn in the laboratory answer: any time chemicals, heat, or glassware are used 5) if you wear contact lenses in the school laboratory answer: advice your science instructor that you wear contact lenses 6) after completing an experiment, all chemical wastes should be answer: disposed of according to your instructor’s directions 7) you are heating a substance in a test tube. always point the open end of the tube answer: away from all people 8) you are heating a piece of glass and now want to pick it up. you should answer: use tongs 9) you have been injured in the laboratory, first you should answer: tell the science instructor at once 10) when gathering glassware and equipment for an experiment, you should Lab Homework answer: clean any glassware that appears dirty, read all directions carefully to know what equipment is necessary, and examine all glassware that appears dirty 11) which display below signifies corrosive answer: c 12) You should place a piece of glass tubing into a rubber stopper after the tubing has been fire polished and cooled.! This is best done by answer: lubricating the tubing with water or glycerin, using a towel or cotton gloves for protection, and twisting the stubbing and stopper carefully 13) long hair in the laboratory must be answer: tied back or kept entirely out of the way with a hairband, hairpin, or other confining device 14) in the laboratory the following should not be worn answer: loose clothing, dangling jewelry, and sandals 15) when you finish working with chemicals, biological specimens, and other lab substances always: answer: wash your hands thoroughly with soap and water 16) Personal eyeglasses do not provide as much protection as answer: a face shield, safety glasses, or splash proof chemical glasses 17) jewelry is potentially unsafe because answer: chemicals can be trapped under it, in contact with sensitive skin 18) what do these symbols mean answer: flammable, poison, and radioactive Lab Homework 19) which one of the following lab safety rules is FALSE answer: you can eat, drink, or smoke in the lab 20) what does this label represent answer: chemistry hazard 1) light microscopes answer: use light and glass lenses to magnify an object 2) one centimeter = ____ millimeters answer: 10 3) a scientist wants to magnify a pollen grain 8,000 times and examine the ridges and pores on its surface. which of the following instruments would be best? answer: a scanning electron microscope 4) a scanning electron microscope is used to study ____, whereas a transmission electron microscope is used to study ______. answer: cell surfaces; internal cell structures 5) the diameter of most animal and plant cells ranges from answer: 10-100 micrometers 6) a pathologist who wants to examine a patients liver cells to determine if the mitochondria has an internal structure defect will likely need to use a Lab Homework answer: transmission electron microscope 7) which of the following is correct -1m=100mm -1mm=10000 -1µm=100nm -1m=1,000,000µm answer: 1m=1,000,000µm 8)these 5 letters represent 5 parts of the microscope: ocular lens, head, dipolar adjustment, objective lens, and stage base, light switch, brightness adjustment, fine adjustment, and coarse adjustment Lab Homework 9) if a 4x objective lens is used, what’s the total magnification answer: 40 10) if a 40x objective lens is used, what is the total magnification answer: 400 11) with increased magnification of a light microscope which statement if FLASE answer: it increases the are of the field of view 12) with the compound microscope, magnification is achieved through the interplay of two lenses- the ocular and objective. which is true? answer: the ocular sense magnifies the specimen, producing the real image, which is further magnified by the objective sense to produce a virtual image 1) the chemical bond between amino acids is called a ___ bond answer: peptide 2) fatty acids are a component of what type of macromolecule answer: lipid 3) how many different amino acids are the building blocks of proteins in the human body? answer: 20 Lab Homework 4) name all three reagents for testing reducing sugar, lipid, and protein, and explain the color changes for each answer: The test for reducung sugar is the Bendict's Reagent, in which a negative result would be present in the colors of blue or green, and the positive result would be present in the colors of yellow, orange, or brick (red).! The test for a lipid is the Sudan IV, in which a negative result would be present in the well dispersed color of red, and the positive result would be present in the layering of oil on the bottom and a non-dispersed red on top. The test for a protein is the Biuret test, in which a negative result would be present in the color of light blue, and a positive result would be present in the color of violet. 5) name two differences between fat and oil answer: A fat is usually a saturated fatty acid, meaning it has only single bonds, while most oils are unsaturated fatty acids, meaning they have a double bond.! Most fats are solid at room temperature, while oils are liquid at room temperature. 6) what does the pic represent? answer: phospholipid 7) what does this structure represent? answer: triglycerides Lab Homework 8) which of the following macromolecules are made from amino acids? answer: proteins 9) where are amino acids called amino acids answer: Amino acids are called such because of the amino and carboxyl group, two of the groups that make up the fundamental structure of the amino acid. 10) write down two names of each of the following carbs: monosaccharides, disaccharides, and polysaccharides answer: Monosaccharides: glucose and galactose.! Disaccharides: lactose and maltose Polysaccharides: starch and cellulose