Concept explainers
For each amino acid
a. methionine
b. serine
Want to see the full answer?
Check out a sample textbook solutionChapter 19 Solutions
Organic Chemistry
- Most amino acids have isoelectric points between 5.0 and 6.0, but the isoelectric point of lysine is 9.7. Explain why lysine has such a high value for its isoelectric point.arrow_forward22-91 Which amino acid does not rotate the plane of polarized light?arrow_forwardExplain why a protein is least soluble in an aqueous medium that has a pH equal to the isoelectric point of the protein.arrow_forward
- 10. Use the information in the table below to draw the structure of the predominant form of each amino acid at physiological pH (pH = 7.4) R side chain pKa (a-COOH) -CH₂CH(CH3)2 -(CH2)4NH2 -(CH2)2CO2H Amino acid Leucine Lysine Glutamic acid L-leucine L-lysine L-glutamic acid 2.36 2.18 2.19 pKa (α-NH3*) pKa (side chain) 9.60 8.95 9.67 10.79 4.25arrow_forwardConsider the amino acid norvaline: O NH2 OH H C3 a. The pKa of the carboxylic acid group is 2.36. The pKa of the amino group is 9.76. Show how to calculate the isoelectric point, pI of this amino acid. b. Draw the structure of norvaline in a solution of NaOH (aq) c. Draw the structure of norvaline in a solution of H2SO4 (aq)arrow_forwardKidney stones are crystals of calcium oxalate that form in the kidney, ureter, or bladder. Small kidney stones are passed out of the body easily, but larger kidney stones may block the ureter causing severe pain. If the [Ca2+] in blood plasma is 5 × 10-3 M, what [C2O42-] must be present to form a kidney stone? (Calcium oxalate Ksp = 2.3 x 10-9)arrow_forward
- H₂N Combination of two or more protein units 7. Which type of cross-link involves interactions between two cysteine amino acids? 8. Which type of cross-link would form between the following amino acids? Η Ο || H₂N-C-C-OH T CH₂ C=O NH₂ Η Ο LL H₂N-C-C-OH T CH₂ OH 9. To what main enzyme class do the nzym that catalyze the following reaction belong? (oxidoreductases, transferases, hydrolases, lyases, isomerases, ligases) HO | || I c-c-N-C-COO + H₂O IT HR₂ R₁ H 1 This bond is cleaved H H₂N-C-COOⓇ I R₂ Wilter navy q H I H₂N-C-C00 1 R₁ •Qisulfide 10. Briefly explain the Lock and Key enzyme model.arrow_forwardThe amino acid histidine has ionizable groups with pK₁ values of 1.8, 6.0, and 9.2, as shown. COOH H¸Ñ—CH CH₂ H 2 CH pH = COO™ H¸Ñ—CH 1.8 pk₁ CH₂ H lonizable -COOH = -COO- group CH COO™ H₂N-CH 6.0 pK₂2 CH₂ H -HisH -His N CH COO™ H₂N-CH 9.2 pk CH₂ H 2 —NH — —NH, CH A biochemist makes up 95 mL of a 0.13 M solution of histidine at a pH of 5.3. She then adds 60 mL of 0.10 M HCl. What is the pH of the resulting solution?arrow_forwardClassify each amino acid by the chemical properties of its side chain (R group) at pH 7. Select the amino acid that fits best in each category. Each amino acid will be selected only once. Which amino acid has a positively charged R group? lysine glutamine glutamate phenylalanine leucinearrow_forward
- The first step in the procedure asks you to prepare five dilutions of the protein standard (BSA) in the range of 0.2 to 1.0 mg/ml. For each concentration, a volume of 1.0 mL should be prepared. Describe how you will prepare these standards using a stock solution of BSA that is 2.0 mg/ml.arrow_forwardThe isoelectric point (p) of the following amino acid is determined to be 5.97. H2N. OH Which of the following is the dominant form at pH 6.5? Select one: H2N. OH H,N H,N 10arrow_forwardThe amino acid histidine has ionizable groups with pKa values of 1.8, 6.0, and 9.2, as shown. COOH H₂N-CH | CH ₂ pH = CH lonizable -COOH group COO- H₂N-CH 1.8 pk₁ CH2 H -COO- CH -HisH+ COO- H₂N-CH 1 6.0 pk2 CH ₂ H H N -His CH -NH COO- H₂N-CH 1 9.2 pk₂ CH2 -NH₂ H -N CH A biochemist makes up 80 mL of a 0.11 M solution of histidine at a pH of 5.1. She then adds 60 mL of 0.10 M HCl. What is the pH of the resulting solution?arrow_forward
- General, Organic, and Biological ChemistryChemistryISBN:9781285853918Author:H. Stephen StokerPublisher:Cengage LearningOrganic And Biological ChemistryChemistryISBN:9781305081079Author:STOKER, H. Stephen (howard Stephen)Publisher:Cengage Learning,Chemistry for Today: General, Organic, and Bioche...ChemistryISBN:9781305960060Author:Spencer L. Seager, Michael R. Slabaugh, Maren S. HansenPublisher:Cengage Learning
- Introduction to General, Organic and BiochemistryChemistryISBN:9781285869759Author:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar TorresPublisher:Cengage LearningWorld of Chemistry, 3rd editionChemistryISBN:9781133109655Author:Steven S. Zumdahl, Susan L. Zumdahl, Donald J. DeCostePublisher:Brooks / Cole / Cengage Learning