4. Assume that a new low-calorie sweetener is developed. The structure is novel and is tested with the Amestest for mutagenicity. The following results are obtained:SampleNumber of hist revertent colonies1distilled waterdistilled water + rat liver enzymessweetener34sweetener + rat liver enzymes65Would you recommend this sweetener to be FDA approved? Why?How do you explain the difference between sample 3 and 4?

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4. Assume that a new low-calorie sweetener is developed. The structure is novel and is tested with the Ames test for mutagenicity. The following results are obtained: %23 Sample 1 Number of his* revertent colonies distilled water distilled water + rat liver enzymes 2 3 sweetener sweetener + rat liver enzymes 6. 4 65 Would you recommend this sweetener to be FDA approved? Why? How do you explain the difference between sample 3 and 4?

4. Assume that a new low-calorie sweetener is developed. The structure is novel and is tested with the Ames test for mutagenicity. The following results are obtained: %23 Sample 1 Number of his* revertent colonies distilled water distilled water + rat liver enzymes 2 3 sweetener sweetener + rat liver enzymes 6. 4 65 Would you recommend this sweetener to be FDA approved? Why? How do you explain the difference between sample 3 and 4?

Human Anatomy & Physiology (11th Edition)

11th Edition

ISBN:9780134580999

Author:Elaine N. Marieb, Katja N. Hoehn

Publisher:Elaine N. Marieb, Katja N. Hoehn

Chapter1: The Human Body: An Orientation

Section: Chapter Questions

Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...

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The transformation results below were obtained with 10 ul of intact plasmid DNA at nine concentrations. The following numbers of colonies are obtained when 100 ul of transformed cells are plated on selective medium: Fill in the following table: Concentration # colonies DNA mass of Fraction of Mass Transformation PGREEN (Concentration x volume OR X spread = x 10ul plasmid solution) PGREEN in cell Cell efficiency Y÷ A suspension suspension spread = 100 ul - total vol cell susp. (Colonies - Mass spread) C x Z = A See (510 ul) HINT: this calculation is constant Given= X Given=Y С. Z. 0.00001 ug/ul | 4 0.00005 ug/ul 12 0.0001 ug/ul 0.0005 ug/ul 32 125 0.001 ug/ul 442 0.005 µg/ul 0.01 ug/ul 0.05 ug/ul 0.1 ug/ul 542 507 475 516 0.5 ug/ul 505
28. In a transformation experiment, DNA is collected from an E. coli donor strain of genotype cys(+) leu(-) thr(+) and used to transform a recipient of genotype cys(-) leu(+) thr(-). Initially, the treated recipient population is plated on a minimal medium supplemented with threonine. Many colonies are obtained. What are possible genotypes of these colonies? A. cys(-) leu(+) thr(+) B. cys(+) leu(+) thr(-) C. All are cys(+) and either + or - for leu and thr D. All are thr(+) and either + or - for cys and leu E. All are thr(-) cys(-) and either + or - - for CYS
13. a. Draw in the corresponding DNA nucleotide that would base pair with the adenine nucleotide shown below using the same level of detail as provided in the image below. Hint: Remember that DNA bases pair in the antiparallel orientation. орасна you A OH H b. How do you know the adenine nucleotide drawn above is from DNA and not RNA?
4. Using the information in problem 3, make another plot showing how DX and DP (rates of production of cells and product) vary with D (on the same graph), covering the same range of dilution rates in problem 3. 5. Genetics & Gene Control A. Explain the difference between a DNA strand, a chromosome and a gene. B. Would a cell with a deletion or a point mutation be more likely to revert back to the original phenotype? Why? C. Define feedback repression. On a basic level, how does this work in a cell?
True of False 9) Gels are read from left to right. Answer: 10) Functional segments of genes (introns) code for proteins, molecules that carry out most cellular functions. Answer: 11) The human genome contains small, repetitive DNA elements that have become randomly inserted into it over millions of years. Answer:
3) Were all of the conditions of a standardized Kirby-Bauer test met as you performed this assay? If not, which were not? 4) What is the significance of colonies that develop within otherwise clear zones of inhibition? If the laboratory report for one of your patients indicated colonies within the zone, what concerns would you have for your patient?
a.) Explain briefly how silica allows us to purify DNA. Be sure to state the relevant biochemical features of silica and DNA as well as any relevant reagents or steps that are important for the purification. Your answer should explain both how we get the DNA to bind in the first place, and how we are able to remove the DNA. You do not (and should not) explain earlier steps in a DNA purification; focus you answer on the silica:DNA interaction. b.) In theory, can a silica spin column also be used to purify RNA? If so, explain how (and why we did not observe RNA when analyzing plasmid DNA via agarose gel electrophoresis). If not, explain why not.
4) Researcher #1 and #2 in your lab each conducted a protein purification. They present you with the following data. The protein-of-interest is indicated by the red arrowhead, and the numbers on top indicate the purification step. Researcher #1 1 2 3 4 SDS-PAGE (Coomassie Stained) Researcher #2 1 2 3 4 5 6 Immunoblot a) Which researcher has more clearly demonstrated purification of the protein-of-interest? Justify your answer. b) What type of chromatography step did researcher #1 most likely conduct in going from step 2➜ 3 based on the gel? Justify your answer.
8. You are studying the biochemical pathway of purrine production. (Purrines are a type of nucleotide used in feline DNA, a little different than the purines in the DNA of lower species like humans.) You have several mutants that cannot make purrine, and you do complementation tests to see how many different genes you've identified. Here are your data: mutant 1 4 6 8 1 3 4 5 + 6 + + + 8. + + 9 + a) What is the deal with mutant #1 and why must you ignore it when figuring out complementation groups? b) For the rest of the problem, ignore mutant #1. List your complementation groups. Hint: every single one of your mutants (except #1 of course) must be in a group. c) How many genes did you, therefore, identify?
4. A 12 kb linear DNA fragment is subject to single or double RE digest and agarose gel electrophoresis, to yield the gel profile shown below. The first lane contains the size marker (M). M Undigested EcoRI control PvuII ECORI + PvuI 12000 bp 9000 bp 6000 bp 5000 bp 4000 bp 2000 bp 1000 bp Explain how the name of the enzyme ECORI is derived. How many sites are there for EcoRI and PvuII respectively on this DNA fragment? b) c) Use the sizes of the DNA bands on the gel to compile a restriction enzyme map of the DNA fragment. Indicate the positions of the restriction enzymes sites for EcoRI and PvuII on the map.
1.a)What is the equivalence point and how does it relate to the recommended proportion of serum to blood in the heme agglutination assay? b. what would the predicted outcome be if you used too little serum in this assay? Why? c. what would the predicted outcome be if you used too much serum in assay? Why?
1. In the SDS-PAGE figure below, looking at lane 6 there are two bands MamP, monomer and MamP dimer (disulfide bonded). Why does the MamP monomer run faster on the gel relative to the MamP dimer? 1 2 3 4 5 6 250 - 130 - 100 70 55 - Hisg MBPtev.Mamf MamP dimer 35 - 25- - MamP monomer 15 - 10 - If the gel was run under non-reducing conditions, would the pattern possibly be different and why? Molecular weight (kD)