生物化學 緒論 PPT課件.ppt

1、生 物 化 學BIOCHEMISTRY,生物與食品工程學院,第一章 緒論,一、生物化學發(fā)展簡歷 二、生物化學的基本內(nèi)涵 三、生物化學在專業(yè)學習中的地位與作用 四、如何學好生物化學 五、學習本課程的基本要求,二、生物化學的基本內(nèi)涵,生物化學 是研究生命活動過程中物質(zhì)基礎 及其化學反應規(guī)律的一門科學。,1、生命活動的物質(zhì)基礎,幾乎所有生物體都使用相同的生物分子，但生物分子的形式是多樣性的，這是生命現(xiàn)象多樣性的物質(zhì)基礎。 （1）功能基團（Functional groups） （2）構件分子（Building molecules） （3）生物大分子（Biomacromolecules） （4）化學鍵（

2、Chemical bonds）,細胞大約由10,000種不同的分子構成，其中水占到5-95%，Na+、K+和Ca2+占1%，其它為有機化合物。構成細胞的分子統(tǒng)稱為生物分子。 生物分子主要由C、H、O、N、P和S等6種元素構成。,常見的功能基團,Functional groups are clusters of atoms with characteristic structure and functions. Most biomolecules contain more than one functional group. Different families of organic compo

3、unds 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,構件分子構成生物大分子的基本單位,單糖、雙糖 甘油、脂肪酸 氨基酸 核苷酸,葡 萄 糖,單 糖,雙 糖,Fatty acids,S

4、tructure of an amino acid,生 物 大 分 子,多 糖：淀粉、糖原、纖維素等 蛋白質(zhì)：結構蛋白、酶、轉(zhuǎn)錄因子等 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 storag

5、e; 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 ma

6、kes 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 學 鍵,共價鍵,非共價鍵 氫鍵 離子鍵 靜電作用力 范氏引力 疏水作用力,Formation

7、 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

8、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 h

9、ydrogen 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 solut

10、ion 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

11、.,van der Waals forces van 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 Waal

12、s 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 coale

13、sce into droplets because water-water interactions are stronger than water-nonpolar substance interactions. This process results from hydrophobic interactions.,小 結,2、生物化學反應的基本規(guī)律, 生命活動過程是由數(shù)千化學反應組成的，相關聯(lián)的化學反應形成代謝途徑，不同的代謝途徑連接形成代謝網(wǎng)絡。,2、生物化學反應的基本規(guī)律, 生物化學反應是由酶催化的，反應的基本原理是相同的。 氧化還原反應 親核反應 異構化反應 水解反應 合成反應 et

14、c,反應很多，但反應的機制是相對較少的,2、生物化學反應的基本規(guī)律, 生物化學反應實現(xiàn)了生命必須的物質(zhì)轉(zhuǎn)換、能量傳遞和信息交流的統(tǒng)一。 物質(zhì)轉(zhuǎn)換生化反應的表現(xiàn)形式生命平臺 能量傳遞生化反應的催化動力生命活力 信息交流生化反應的目標實現(xiàn)生命意義,2、生物化學反應的基本規(guī)律, 生物化學反應發(fā)生在細胞中，體現(xiàn)出生命的系統(tǒng)性。 生物分子的相互作用 細胞器之間的相互作用 細胞內(nèi)的信號 細胞生命活動的協(xié)調(diào)與統(tǒng)一 etc,2、生物化學反應的基本規(guī)律, 生物化學發(fā)應是動態(tài)的，具有方向性。 物質(zhì)轉(zhuǎn)換、能量傳遞、信息交流是無時不停的； 生化反應是可以調(diào)節(jié)的； 生化反應的平衡是動態(tài)的； 生化反應是有方向的。,三、生

15、物化學在本專業(yè)學習中地位與作用,基礎理論作用（學習后續(xù)課程的基礎） 實踐動手作用（基本實驗技能的培訓） 生物思想作用（生化的角度看生命現(xiàn)象）,四、如何學好生物化學,4R法（Read, Remember, Repeat, Review） 做好筆記 做好習題 教學互動,學習生物化學的“分子哲學”法,五、學習本課程的基本要求,需要掌握的核心內(nèi)容 氨基酸的基本結構、性質(zhì)、分離鑒定方法 蛋白質(zhì)的基本結構、性質(zhì)、功能、研究方法 酶催化的基本理論和調(diào)節(jié)，特別是米氏方程 核酸的基本組成單位、結構、性質(zhì)、功能、研究方法 DNA復制、RNA合成及蛋白質(zhì)合成的基本過程 基本糖代謝途徑及生物氧化 脂肪酸分解與合成的基本過程 蛋白質(zhì)和氨基酸分解與合成的一般概念 代謝途徑的相互關系及代謝調(diào)控的