生物化学课件英文版教授讲授chapter

1、Molecular Design of LifeCHAPTER 1 PRELUDE Biochemistry is the study of the molecular basis of life. There is much excitement and ferment (outstanding achievements) in biochemistry through-out the world for: 1.the chemical mechanisms of many central processes of life are now understood discovery of D

2、NA double-helix structure.elucidation of flow of information from gene to protein.determination of 3D-structure and mechanism of action of many protein molecules.unraveling of central metabolic pathways.much learned about molecular machines that harvest energy, detect signals, and process informatio

3、n.development of binant DNA technology. mon molecular patterns and principles underlie the diverse expressions of lifeuse same building blocks构建元件 to construct macromolecules.the same flow of genetic information from DNA to RNA to protein.ATP, the universal currency of energy is generated in similar

4、 ways.3.biochemistry is profoundly influencing medicineelucidation of molecular lesions causing many genetic diseases.discovery and implementation of effective therapies.clinical diagnostics, DNA probes探针 in the precise diagnosis of inherited disorders, infectious diseases, and cancers.valuable prot

5、eins produced by genetically engineered strains of bacteria containing binant DNA, e.g. insulin, growth hormone, and stimulators of blood cell development.rational design of new drugs.designed changes in genetic endowment of plants (in agriculture).4.the rapid development of powerful biochemical con

6、cepts and techniques in recent years has enabled investigators to tackle some of the most challenging and fundamental problems in biology and medicine.How does a fertilized egg受精卵 give rise to cells as different as those in muscle, the brain, and the liver(分化)?How do cells find each other相互识别 in for

7、ming a complex organ?How is the growth of cells controlled生长调控?What are the causes of cancer?What is the molecular basis of mental disorders such as Alzheimers disease阿尔茨海默病(早老性痴呆) and schizophrenia精神分裂症(早发性痴呆)?Molecular models depict 3-D structure interplay between the 3-D structure of biomolecules

8、 and their biological function, three types of atomic models to depict molecular architecturethe size and configuration构型 of an atom are determined by its bonding properties and van der Walls radius.ball-and-stick 球棍models.Skeletal骨架 models.space-filling models空间充满模型ball-and-stick and skeletal model

9、sComparison modelsspace, time, and energy angstron (=1010 m) is customarily used as the measure of length (space). ps, ns, s, ms and s for time. kcal/mol (or kJ/mol) for energy.Reversible molecular interactions are the heart of the dance of life. Weak, noncovalent forces play key roles in faithful r

10、eplication of DNAfolding of proteins into intricate 3-D formsdetection of signal moleculesthree fundamental noncovalent bonds areelectrostatic bonds hydrogen bonds Van der Walls bonds (无共用电子对,无化学键形成)hydrogen bondsVan der Walls bondsthe biologically important properties of water are its polarity and

11、cohesiveness极性和粘性 water is polar molecule water is highly cohesivewater solvates polar molecules and hence weakens ionic and hydrogen bonds water is an excellent solvent for polar molecules becauseit greatly weakens electrostatic forces and hydrogen bonding between polar molecules by competing for t

12、heir attractionexcellence of water as a solvent poses a problem, for it also weakens interactions between polar moleculeshydrophobic 疏水性attractions: nonpolar groups tend to associate in water nonpolar molecules or groups tend to cluster together in waterhydrophobic attractions are a major driving force in:folding of macromoleculesbinding of substrates to enzymesformation of cell membranesthe basis of a hydrophobic attraction is this enhanced f