蛋白质是生物体的重要组成部分,在生物体系中起着核心作用,占活细胞干 重的50%左右。虽然有关细胞的进化和生物组织信息存在于DNA中,但是,维持 细胞和生物体生命的化学和生物化学过程全部是由酶来完成。众所周知,每一种 酶在细胞中是高度专一的催化一种生物化学反应,酶是具有催化功能的蛋白质。 此外,有的蛋白质,例如胶原蛋白、角蛋白和弹性蛋白等,在细胞和复杂的生物 体中作为结构单元,对于细胞的结构和功能起着重要作用

苫味和甜味同样依赖于分子的立体化学结构,两种感觉都受到分子特性 的制约,从而使某些分子产生苦味和甜味感觉。糖分子必须含有两个可以由 非极性基团补充的极性基团,而苦味分子只要求有一个极性基团和一个非极 性基团。有些人认为,大多数苦味物质具有和甜味物质分子一样的AH/B部分 和疏水基团,位于感觉器腔扁平底部的专一感觉器部位内的AH/B单位的取向, 能够对苦味和甜味进行辨别。适合苦味化合物定位的分子,产生苦味反应, 适合甜味定位的分子引起甜味反应,如果一种分子的几何形状能够在两个方 位定位,那么将会引起苦味-甜味反应

叶绿素a和脱镁叶绿素a均可溶于乙醇、乙醚、苯和丙酮等溶剂,不溶于水,而纯 品叶绿素a和脱镁叶绿素α仅微溶于石油醚。叶绿素b和脱镁叶绿素b也易溶于乙醇 乙醚、丙酮和苯,纯品几乎不溶于石油醚,也不溶于水。因此,极性溶剂如丙酮、甲醇、 乙醇、乙酸乙酯、吡啶和二甲基甲酰胺能完全提取叶绿素 叶绿a纯品是具有金属光泽的黑蓝色粉末状物质,溶点为117~120℃,在乙醇溶液 中呈蓝绿色,并有深红色荧光

目录 实验一水分的测定(烘重量法) 实验二食品水分活度的测定(直接测定法) 实验三食品水分活度(Aw)的测定(水分活度仪测定法)-- 实验四粗灰分的测定(干式灰化法)

Chapter F14 Power Notes Statement of Cash Flows Learning Objectives 1. Purpose of the Statement of Cash Flows 2. Reporting Cash Flows 3. Statement of Cash Flows The Indirect Method 4. Statement of Cash Flows -The Direct Method 5. Financial Analysis and Interpretation

Chapter F13 Power notes Bonds Payable and Investments in Bonds Learning Objectives 1. Financing Corporations 2. Characteristics of Bonds Payable 3. The Present-Value Concept and Bonds Payable 4. Accounting for Bonds Payable 5. Bond Sinking Funds 6. Bond Redemption 7 Investments in bonds 8. Corporation Balance Sheet 9. Financial Analysis and Interpretation

Chapter F11 Power notes Corporations: Organization, Capital Stock, Dividends Learning Objectives 1. Nature of a corporation 2. Stockholders'Equity 3. Sources of Paid-in Capital 4. Issuing Stock 5. Treasury Stock Transactions 6. Stock Splits 7. Accounting for dividends 8. Financial Analysis and Interpretation

Chapter F9 Power notes Fixed Assets and Intangible Assets Learning objectives 1. Nature of Fixed Assets 2. Accounting for Depreciation 3. Capital and Revenue Expenditures 4. Disposal of Fixed Assets 5. Leasing Fixed Assets 6. Internal Control of fixed assets 7 Natural resources 8. Intangible Assets 9. Financial Reporting 10. Financial Analysis and Interpretation

Chapter F7 Power notes Receivables Learning objectives 1. Classification of receivables 2. Internal Control of receivables 3. Uncollectible receivables 4. Uncollectibles- Allowance Method 5. Uncollectibles- Direct Write-Off Method 6. Characteristics of notes receivable 7. Accounting for Notes Receivable 8. Balance Sheet Presentation 9. Financial Analysis and Interpretation

Chapter F4 Power notes Completing the Accounting Cycle Learning Objectives 1. Work sheet 2. Financial Statements 3. Adjusting and Closing Entries 4. Accounting Cycle 5. Fiscal year 6. Financial Analysis and Interpretation