《生物化学绪论》PPT课件.ppt

生 物 化 学BIOCHEMISTRY,生物与食品工程学院,第一章 绪论,一、生物化学发展简历二、生物化学的基本内涵三、生物化学在专业学习中的地位与作用四、如何学好生物化学五、学习本课程的基本要求,二、生物化学的基本内涵,生物化学 是研究生命活动过程中物质基础 及其化学反应规律的一门科学。,1、生命活动的物质基础,几乎所有生物体都使用相同的生物分子，但生物分子的形式是多样性的，这是生命现象多样性的物质基础。（1）功能基团（Functional groups）（2）构件分子（Building molecules）（3）生物大分子（Biomacromolecules）（4）化学键（Chemical bonds）,细胞大约由10,000种不同的分子构成，其中水占到5-95%，Na+、K+和Ca2+占1%，其它为有机化合物。构成细胞的分子统称为生物分子。生物分子主要由C、H、O、N、P和S等6种元素构成。,常见的功能基团,Functional groups are clusters of atoms with characteristic structure and functions.Most biomolecules contain more than one functional group.Different families of organic compounds result when hydrogen atoms on organic molecules are replaced by different functional groups.The distinct chemical properties of each functional group contribute to the behavior of any molecule that contains it.,Functional groups,构件分子构成生物大分子的基本单位,单糖、双糖甘油、脂肪酸氨基酸核苷酸,葡 萄 糖,单 糖,双 糖,Fatty acids,Structure of an amino acid,生 物 大 分 子,多 糖：淀粉、糖原、纤维素等蛋白质：结构蛋白、酶、转录因子等核 酸：DNA、RNA、dsRNA etc,Starch,Glycogen,Cellulose,Structure of cellulose as it occurs in a plant cell wall,Lipids are composed of three fatty acids(usually)covalently bonded to a 3-carbon glycerol.Functions:Long-term energy storage;Structural components;Hormones;insulators and cushions.,Structure of a phospholipid,Phospholipids and glycolipids are important structural components of cell membranes.Phospholipids are modified so that a phosphate group(PO4-)is added to one of the fatty acids.The addition of this group makes a polar head and two nonpolar tails.,Proteins are very important in biological systems as control and structural elements.The building block of any protein is the amino acids.,HIV p17 protein and similarities of its structure to gamma interferon.,化 学 键,共价键,非共价键氢键离子键静电作用力范氏引力疏水作用力,Formation of a covalent bond between two Hydrogen atoims.,Formation of covalent bonds in methane,Table Salt Crystal,Formation of a crystal of sodium chloride.Each positively charged sodium ion is surrounded by six negatively charged chloride ions;likewise each negatively charged chloride ion is surrounded by six positively charged sodium ions.The overall effect is electrical neutrality.,Ionic bond,Formation of a hydrogen bond between the hydrogen side of one water molecule and the oxygen side of another water molecule.,The presence of polar areas in the amino acids that makeup a protein allows for hydrogen bonds to form,giving the molecule a three-dimensional shape that is often vital to that proteins proper functioning.,Electrostatic interactions Electrostatic interactions occur between oppositely charged atoms or groups.An important aspect of all electrostatic interactions in aqueous solution is the hydration of ions.Because water molecules are polar,they are attracted to charged ions.As ions become hydrated,the attractive force between them is reduced,and the charged species dissolves in the water.,Dissolution of an ionically bonded compound,sodium chloride,by water molecules.,van der Waals forcesvan der Waals forces are relatively week,transient electrostatic interactions.They occur between permanent and/or induced dipoles.They may be attractive or repulsive,depending on the the distance between the atoms or groups involved.There are three types of van der Waals forces:Dipole dipole interactions Dipole induced dipole interactions Induced dipoles induced dipoles interactions.,The mean van der Waals diameter of water is identical with that of isoelectronic neon(2.82).,Hydrophobic interactionsAs soon as nonpolar substances are mixed with water,they coalesce into droplets because water-water interactions are stronger than water-nonpolar substance interactions.This process results from hydrophobic interactions.,小 结,2、生物化学反应的基本规律,生命活动过程是由数千化学反应组成的，相关联的化学反应形成代谢途径，不同的代谢途径连接形成代谢网络。,2、生物化学反应的基本规律,生物化学反应是由酶催化的，反应的基本原理是相同的。氧化还原反应亲核反应异构化反应水解反应合成反应etc,反应很多，但反应的机制是相对较少的,2、生物化学反应的基本规律,生物化学反应实现了生命必须的物质转换、能量传递和信息交流的统一。物质转换生化反应的表现形式生命平台能量传递生化反应的催化动力生命活力信息交流生化反应的目标实现生命意义,2、生物化学反应的基本规律,生物化学反应发生在细胞中，体现出生命的系统性。生物分子的相互作用细胞器之间的相互作用细胞内的信号细胞生命活动的协调与统一etc,2、生物化学反应的基本规律,生物化学发应是动态的，具有方向性。物质转换、能量传递、信息交流是无时不停的；生化反应是可以调节的；生化反应的平衡是动态的；生化反应是有方向的。,三、生物化学在本专业学习中地位与作用,基础理论作用（学习后续课程的基础）实践动手作用（基本实验技能的培训）生物思想作用（生化的角度看生命现象）,四、如何学好生物化学,4R法（Read,Remember,Repeat,Review）做好笔记做好习题教学互动,学习生物化学的“分子哲学”法,五、学习本课程的基本要求,需要掌握的核心内容氨基酸的基本结构、性质、分离鉴定方法蛋白质的基本结构、性质、功能、研究方法酶催化的基本理论和调节，特别是米氏方程核酸的基本组成单位、结构、性质、功能、研究方法DNA复制、RNA合成及蛋白质合成的基本过程基本糖代谢途径及生物氧化脂肪酸分解与合成的基本过程蛋白质和氨基酸分解与合成的一般概念代谢途径的相互关系及代谢调控的基本概念,五、学习本课程的基本要求,上课保证、作业、习题练习教材阅读实验技能,教材与参考书,教 材：生物化学，王镜岩等编，高等教育出版社生物化学实验指导书，生物化学课程组编生物化学课堂同步训练，生物化学课程组编参 考 书：生物化学，王希成编，清华大学出版社生物化学与生物物理进展（杂志）（影印版，科学出版社）参考网站：剑桥大学出版社，生物化学电子版 台湾大学，生物化学教学课件,