Biochemistry, 4th Edition P18. Continuing Garrett and Grisham's innovative conceptual and organizing framework, "Essential Questions," BIOCHEMISTRY guides students through course concepts in a way that reveals the beauty and usefulness of biochemistry in the everyday world. Streamlined for increased clarity and readability, this edition also includes new photos and illustrations that show the subject matter consistently throughout the text. New end-of-chapter problems, MCAT practice questions, and the unparalleled text/media integration with the power of CengageNOW round out this exceptional package, giving you the tools you need to both master course concepts and develop critical problem-solving skills you can draw upon. | Chapter 5 Appendix 133 where pp is the density of the particle or macromolecule pm is the density of the medium or solution V is the volume of the particle and f is the frictional coefficient given by f Ff v where v is the velocity of the particle and Ff is the frictional drag. Nonspherical molecules have larger frictional coefficients and thus smaller sedimentation coefficients. The smaller the particle and the more its shape deviates from spherical the more slowly that particle sediments in a centrifuge. Centrifugation can be used either as a preparative technique for separating and purifying macromolecules and cellular components or as an analytical technique to characterize the hydrodynamic properties of macromolecules such as proteins and nucleic acids. Like the Greek sea god Proteus who could assume different forms proteins act through changes in conformation. Proteins from the Greek proteios meaning primary are the primary agents of biological function. Proteus Old Man of the Sea Roman period mosaic from Thessalonika 1st century . National Archaeological Museum Athens Ancient Art and Architecture Collection Ltd. Bridgeman Art Library London New York Growing in size and complexity Living things masses of atoms DNA protein Dancing a pattern ever more intricate. Out of the cradle onto the dry land Here it is standing Atoms with consciousness Matter with curiosity. Stands at the sea Wonders at wondering I A universe of atoms An atom in the universe. Richard P. Feynman 1918-1988 From The Value of Science in Edward Hutchings Jr. ed. 1958. Frontiers of Science A Survey. New York Basic Books. KEY QUESTIONS What Noncovalent Interactions Stabilize the Higher Levels of Protein Structure What Role Does the Amino Acid Sequence Play in Protein Structure What Are the Elements of Secondary Structure in Proteins and How Are They Formed How Do Polypeptides Fold into ThreeDimensional Protein Structures How Do Protein Subunits Interact at the Quaternary .
