NH2 н 'N' Н + H20 + NH3 H. Sugar Sugar Cytosine Uracil (a) Deamination of cytosine NH2 CHз Н. N. CH3 + H,0 + NH3 H. H. Sugar Sugar 5-methylcytosine Thymine (b) Deamination of 5-methylcytosine FIGURE 19.8 Spontaneous deamination of cytosine and 5-methylcytos ine. (a) The deamination of cytosine produces uracil. (b) The deamination of 5-methylcytosine produces thymine. エエエ

NH2 н 'N' Н + H20 + NH3 H. Sugar Sugar Cytosine Uracil (a) Deamination of cytosine NH2 CHз Н. N. CH3 + H,0 + NH3 H. H. Sugar Sugar 5-methylcytosine Thymine (b) Deamination of 5-methylcytosine FIGURE 19.8 Spontaneous deamination of cytosine and 5-methylcytos ine. (a) The deamination of cytosine produces uracil. (b) The deamination of 5-methylcytosine produces thymine. エエエ

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter26: Synthesis And Degradation Of Nucleotides

Section: Chapter Questions

Problem 10P

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The following amino acids that are often found inside globulin molecules are () A, Tyr B, Phe C, Asn D, Glu True of false 1. In the de novo synthesis of purine nucleotides and pyrimidine nucleotides, base rings are first synthesized and then corresponding nucleotides are formed with phosphoribose. () 2. Transcription is the process of transferring genetic information from DNA to RNA. DNA is synthesized under the catalysis of RNA polymerase, and the direction of synthesis is from the 5 'end to the 3' end. () 3. The change of protein conformation is caused by the breaking of covalent bonds within the molecule. () 4. In very high and very low pH solutions, amino acids exist mainly in non-ionic form. () 5. The active center of an enzyme usually consists of several amino acid residues adjacent to each other in the primary structure. ()
A chain NH3 NH3 B chain Gly Phe 2. The protein pictured below is bovine insulin. Determine the number and the size of the fragments that would be generated upon treatment with the following: İle Val Val Asn Gln Gln 5 Ġln 5 His look for the cleavage points (a) without DTT and (b) with DTT. Cys Leu Cys S-S Cys Without DTT With DTT Ala Ģly Ser Ser Trypsin 10 Val 10 His Cys Leu Chymotrypsin Ser Val Leu Glu BrCN Tyr Ala 15 Gln 15 Leu Leu Тyr Ġlu Leu Ásn Val Тyr Cys 20 Çys 20 Gly Asn Glu Arg Reagent (source) Trypsin (bovine pancrease) Chymotrypsin (bovine pancrease) Staphylococcus V8 protease Pepsin (porcine pancrease) Cyanogen bromide (chemical)(CnBr) Specificity Lys, Arg (C) Phe, Trp, Tyr (C) Glu, Asp (C) Phe, Trp, Tyr (N) Met (C) Gly Phe 25 Phe Тyr Thr Pro Lys 30 Ála
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E Threonine 6. You have identified some intermediates in threonine synthesis: A, B, C, D and E. You grow a few of your mutants in the presence of these different intermediates to determine the order in which the gene products act. Below are your results. A (+) means growth and a (-) means no growth. Given these data, draw the best possible pathway for the synthesis of threonine. The diagram should use arrows to indicate one intermediate being changed to another intermediate. Indicate which gene produces the product responsible for the conversion by listing the mutant in that gene above the arrow. Mt1 Mt2 Mt4 Mt7
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A Leu →Ala mutation at a site buried in the core of the enzyme lysozymeis found to be destabilizing. Explain the observed effect of this mutationon lysozyme stability by predicting how enthalpy (ΔH°), conformationalentropy (ΔS°peptide), and the hydrophobic effect (ΔS°solvent) are expected to change for the mutant compared to wild-type lysozyme. Explain how ΔG°for unfolding is affected by your predicted changes in enthalpy or entropy.
2B. S. aureus hemolysin B attacks the RBC cell membrane by hydrolyzing the sphingomyelin headgroup: ОН HN .R hemolysin B cuts this bond i) Draw a plausible mechanism of hydrolysis for this lipid headgroup. Let B- and BH be general base and general acid. 00-P-O LOR2 OR, ii) Why is this damaging to the overall membrane architecture of the RBC?
1. Know the structures of DNP-glycine and of the chromophore associated with cytochrome C. Low Salt Volume of blue band = 5.2 ml (Void Volume) Volume of yellow band = 2.6ml Volume of red band = 11ml High Salt Volume of blue band = 4.2 ml -> Void Volume Volume of yellow band = 5.2 Volume of red band = 1.2 2. What is the exclusion limit and the fractionation range for CM-Sephadex resin used? 3. What are the ion exchange reactions which occur when the coloured mixture is first applied to the column under low salt conditions? What exchange reactions occur upon the change of buffer from low salt to high salt concentrations? 4. What were the values for Vo and Vi for this column? Where the values for Vo and Vi the same under both conditions? 5. Explain the order in which the various components of the mixture elute under each condition in terms of their physical properties and the nature of the CMSephadex G-50 column. Would the same order be observed with a G-50 Sephadex column (i.e. no…