Chapter 3 Exploring Proteins and Proteomes 3 6 MALDI-TOF is the abbreviation for Ans:Matrix-Assisted Laser Desorption and Ionization Time of Flight mass spectrometer Section:3.5 7 Automated peptide synthesis involves the activation of the carboxyl group of the incoming amino acid by and then reaction with the amino group of the growing peptide chain. Ans:dicyclohexylcarbodiimide Section:3.4 8 Polypeptides can be fragmented into smaller peptides by cleavage with chymotrypsin,which hydrolyzes the peptide bond at the C-terminal side of residues Ans:phenyalanine,tyrosine,and tryptophan Section:3.2 9 gels are often used as the media for electrophoretic techniques such as SDS-PAGE and isoelectric focusing. Ans:Polyacrylamide Section:3.2 10 The mobility of proteins in SDS-PAGE is inversely proportional to the Ans:logarithm of their mass Section:3.1 Multiple Choice Questions 1 When enzymes are purified,the assay is often based on A) light absorbance. D) temperature changes. B) catalytic activity. E) mRNA levels. C) pH. Ans:B Section:3.1 2 Proteins that are not catalysts are often assayed using A) antibody binding assays. D) None of the above. B) catalytic activity. E) All of the above. C) amino acid analysis Ans:A Section:Introduction 3 What is the advantage of adding SDS to gel electrophoresis? A) SDS colors the proteins for visualization. B) SDS reduces disulfide bonds. C) SDS allows proteins to be separated on the basis of approximate mass. D) None of the above. E)All of the above. Ans:C Section:3.1 4 Two-dimensional electrophoresis is a combination of what two techniques? A)isoelectric focusing and affinity chromatography B) ion-exchange chromatography and SDS-PAGE C) affinity chromatography and SDS-PAGE D) isoelectric focusing and SDS-PAGE E) isoelectric focusing and ion-exchange chromatography Ans:D Section:3.1Chapter 3 Exploring Proteins and Proteomes 3 6 MALDI-TOF is the abbreviation for __________________. Ans: Matrix-Assisted Laser Desorption and Ionization Time of Flight mass spectrometer Section: 3.5 7 Automated peptide synthesis involves the activation of the carboxyl group of the incoming amino acid by __________________ and then reaction with the amino group of the growing peptide chain. Ans: dicyclohexylcarbodiimide Section: 3.4 8 Polypeptides can be fragmented into smaller peptides by cleavage with chymotrypsin, which hydrolyzes the peptide bond at the C-terminal side of __________________ residues. Ans: phenyalanine, tyrosine, and tryptophan Section: 3.2 9 __________________ gels are often used as the media for electrophoretic techniques such as SDS-PAGE and isoelectric focusing. Ans: Polyacrylamide Section: 3.2 10 The mobility of proteins in SDS-PAGE is inversely proportional to the _____________. Ans: logarithm of their mass Section: 3.1 Multiple Choice Questions 1 When enzymes are purified, the assay is often based on A) light absorbance. D) temperature changes. B) catalytic activity. E) mRNA levels. C) pH. Ans: B Section: 3.1 2 Proteins that are not catalysts are often assayed using A) antibody binding assays. D) None of the above. B) catalytic activity. E) All of the above. C) amino acid analysis. Ans: A Section: Introduction 3 What is the advantage of adding SDS to gel electrophoresis? A) SDS colors the proteins for visualization. B) SDS reduces disulfide bonds. C) SDS allows proteins to be separated on the basis of approximate mass. D) None of the above. E) All of the above. Ans: C Section: 3.1 4 Two-dimensional electrophoresis is a combination of what two techniques? A) isoelectric focusing and affinity chromatography B) ion-exchange chromatography and SDS-PAGE C) affinity chromatography and SDS-PAGE D) isoelectric focusing and SDS-PAGE E) isoelectric focusing and ion-exchange chromatography Ans: D Section: 3.1