1、第一章 营养学基础第一节 蛋白质 一目的和要求本节是营养学第一章中重点内容；要做到全部掌握。二重点和难点重点：蛋白质生理功能，必需氨基酸。蛋白质营养学评价，食物来源和供给量。难点：食物蛋白质营养学评价有关指标及原理。三、教学安排教学时数：2 学时四、教学方法重点讲授，复习、提问、讨论相结合。应用多媒体课件。五、授课内容第一节 蛋白质概念，生理功能，氨基酸和必须氨基酸，蛋白质在体内的消化、吸收和代谢食物蛋白质营养评价，蛋白质的营养不良，蛋白质来源及供給量一. 蛋白质的生理功能1.是人体组织的构成成分2.是构成体内各种重要生理活性物质增加免疫功能维护神经系统的正常功能遗传信息的控制维持毛细血管的正
2、常渗透压运输功能维持血液的酸碱平衡参与凝血过程3.供给热能蛋白质的组成及一般性质基本组成元素：碳、氢、氧、氮一般性质：高分子物质，不能透过半透膜；两性分子，具有酸性和碱性，可成为缓冲体系与水形成乳胶悬浮液可发生变性和凝固二. 氨基酸和必需氨基酸1.氨基酸和肽2.必需氨基酸(essential amino acid ,EAA)概念：种类 异亮氨酸、亮氨酸、 赖氨酸蛋氨酸、 苯丙氨酸、 苏氨酸色氨酸、 缬氨酸、 组氨酸氨基酸膜式和限制性氨基酸氨基酸模式与限制氨基酸氨基酸模式（Amino Acid Pattern ）限制氨基酸（limiting amino acid ）优质蛋白质及参考蛋白质 优质蛋
3、白质参考蛋白质(reference protein) ：鸡蛋蛋白，人乳蛋白蛋白质的互补作用(supplementary action)蛋白质是由多种氨基酸构成的。由于各种食物中的氨基 酸组成不尽相同，在某一种食物中缺乏的氨基酸可能在另一种食物中含量丰富。当食物蛋白质中某一种或某几种氨基酸缺乏或不足时，则使合成机体组织蛋白质受到限制。如果将各种食物按合适的比例混合食用，其蛋白质可起到相互补充的作用，即各种食物蛋白质中的氨基酸可以取长补短，最后成为一种更适合人体吸收利用的较为完美的混合膳食，从而起到提高蛋白质利用率的作用，这就称为蛋白质的互补作用。三、蛋白质在体内的消化、吸收和代谢摄入的蛋白质在体
4、内经酶的水解最终成为各种氨基酸，但实际上人体的血浆中存在两种氨基酸的来源：即从体外摄入蛋白质和体内蛋白质分解后被机体吸收再利用的氨基酸。氮平衡(nitrogen balance)摄入氮与排出氮的关系。表达式 : NB=I-（U+F+S）I=摄入氮 U=尿氮 F=粪氮 S=皮肤损失氮 零平衡 摄入氮=排出氮 氮平衡 正平衡 摄入氮排出氮 负平衡 摄入氮 fatty tissue)(2) Gender male female(3) Age 2% of decline per 10 years after age 30 5% of decline per 10 years after age 60(
5、4) Nutrition stateLow energy intake decreases BMR about 10%-20%(5) Pregnancy increases BMR(6) Body temperature Fever increases BMR(7) High or low air temperature, hormone system activity, nerve and eating too much increase BMR (Adaptive therogenesis，适应性生热作用)(8) Caffeine and tobacco increase BMR(二） P
6、hysical ActivityThe energy needed during physical activity depends on body lean mass, intensity (强度) and time of activity. The energy is about 15%-30% of total energy use in sedentary(久坐的) people.（三）Specific dynamic action (or Thermic Effect of Food,TEF)食物特殊动力作用或食物热效应1Definition：The amount of extra
7、energy used by body during digestion, absorption, metabolism, and storage of energy-yielding nutrients.2Energy expenditurecarbohydrates 5%-6% of total calorie produced by carbohydrateslipids 4%-5% of thatprotein 30% of thatmixed food 10% 0f total energy consumed（消耗）3The mechanism (1) Energy storage:
8、 ATP and fat(2) Sympathetic nervous system activity (交感神经系统活动)4Affecting factors(1) protein-rich food is much higher then others(2) large meals show higher values than normal meals(3) TEF decreases with advancing age.(4) Meal frequency.三、热能需要量的确定 Estimating energy rquirements（一）calculation1calculati
9、ng the total energy expenditurebasal metabolismphysical activitiesspecific dynamic action2 Nutritional survey (or Dietary survey):营养或膳食调查(二）measuring energy use by body（测量法）1 Direct calorimetry2 Indirect calorimetry四、热能推荐摄入量 Energy Recommended Nutrition Intake, RNI五、Health and energy intake（一）the ri
10、sk of excessive energy（二）限食 Energy restrictionIt is beneficial to prevention of many diseases especially for old people, and prolonging life.第五节 矿物质 SECTION 5 MIMERALS一目的和要求1掌握钙、铁、碘、锌、硒等元素的生理功能，吸收与代谢，缺乏病，食物来源与供给量。2熟悉人体无机盐和微量元素的构成。3了解磷、铜、锰、钴、钼、铬、镍等有关内容。 二重点和难点1重点为钙、铁、碘、锌、硒的生理功能，缺乏病，代谢及食物来源与供给等。2元素的代谢
11、及有关机理。 三、教学安排教学时数：4 学时四、教学方法重点讲授，复习、提问、讨论相结合。应用多媒体课件。五、授课内容 Introduction1.Elements in human body1.1 Total elements In human body is 0ver 80.1.2 Essential elements in human body over 20, of them about 20 are mineral elements(1) Macroelements: Ca, P, Na, K, Mg, S, CL.(2) Microelements: Fe, Zn, Se, I,
12、Cu, Co, Cr, F, Mn, Mo, Si, Ni, B, V.2. Function1.1 Composition of human body1.2 Maintain the pH and osmotic pressure (渗透压) of body liquids. 1.3 Regulating the exciting of nerve and muscle 1.4 Components of prosthetic group(辅基), hormone, vitamin, protein, nucleic acid, and activator（激活剂） of enzyme.1.
13、5The othersCalcium1Calcium in human bodyCa in the body: 850-1200g1.5%-2.0% of body weightBone , teeth, 99%: Combined form, 0.5%: Ion, 0.5%：Hydroxyapatite combined with Miscible Ca Pool（羟磷灰石） protein and （混溶钙池）amorphous Ca citric acid In blood, extra-（未定形钙） cellular fluid, soft tissue, and exchangeab
14、le2. Function2.1 Principal component of skeletal tissueosteoblasts(成)Bone Ca (miscible Ca pool)Osteoclasts(破)Renewal:Children 1-2 yearAdult 10-12 y (2%-4% per year, 700mg/d)After 40y, Ca in the bone decreased by 1% per year: earlier infemales than in males; Most rapidly during first 3years After men
15、opause;Taller people less rapidly.2.2 Regulating neuromuscular(神经肌肉) excitability, maintaining transmission of nerve impulses(神经冲动) and heart beats.2.3 Influencing enzymereaction: ATPase(三磷酸腺苷酶), proteinase(蛋白酶),Lipase(脂肪酶), succinodehydrogenase(琥珀酸脱氢酶)。2.4 Others: hormone secretion, blood coagulati
16、on(凝结), acid-base balance, normal colloid(胶体).3Absorption and Metabolism3.1 Mechanism of absorption: in the small intestine(1) Transcellular(跨细胞 ): saturable(可饱和的 ) (active) transfer that involves a calcium-biding protein, calbindin(钙结合蛋白 ).(2) Paracellular(同细胞水平 )3.2 Affecting factors(1) Age childr
17、en: 75% 0f ingested Ca; 40% of food Caadults: 30%-60%; 20% 70y 1/3 of adults; female(3) Physiological situation: pregnancy and breast-feed others(4) Body Ca conc.(5) Dietary factorsincreasing Ca absorption: Vit. D, lactose, amino acids: lysine argininedecreasing : phytate(植酸盐), oxalate(草酸盐), fibre,
18、fatty acid, alcohol; thyroid hormone(甲状腺素), cortisol(皮质醇), and antibiotics: penicillin, neomycin,chloramphenical(氯霉素)3.3 Excretion3.3.1 Fecal Ca 194 73 mg/d in the American men from unabsorbed Ca and endogenous Ca(内源性钙)3.3.2 Urine Ca：diets containing 600-800 mg/d ranges between 80-250mg in urine.3.3
19、.3 Sweat Ca: 20-30mg/d; 1g/d at high temp.3.3.4 Milk Ca: 150-300mg/d3.4 Biologic control system for homeostasis(体内平衡) of CaVit.D and parathyin(甲状旁腺素): renal reabsorptionCalcitonin(降血钙素): inhibiting bone loss and increasing urine CaCalmodulin(钙调节素): regulating the Ca in the cell.4 DRIs of Ca4.1 Estim
20、ating DRIs（膳食参考摄入量）(1) Infants: mean intake of breast milk(母乳) (2) Others: Ca balance test(平衡试验)(3) Direct measure4.2 DRIs (mg/d )5 Dietary sourcemilk, small shrimps(小虾), kelp(海带), legumes(豆类): soy bean、 black soya bean(黑豆), red bean(红豆), sesame paste(芝麻酱), and many Ca supplements(钙补充剂).Iron (铁)1 Bo
21、dy ironBody iron (4-5g)Functional Fe (75%): Storage Fe (25%):2 Physiologic functions2.1 Important role in oxygen and electron transport2.2 Others: catalyzing -carotene Vit.A; promoting produce of antibody;lipids transport in blood;detoxifying drugs in liver-3 Absorption and Metabolism3.1 Absorption
22、of nonheme iron(非血红素铁)3.1.1 factors of decreasing absorption(1) rapid transit time(2) achylia(胃液缺乏), malabsorption syndromes (3) precipitation(沉淀) by alkalinization(碱化), phosphates(4) phytates(植酸), oxalate(草酸) and antacids(抗酸剂)(5) iron dosage3.12 factors of increasing absorption(1) iron dosage(2) vi
23、t.C, B2; amino acids: cysteine(半胱氨酸 )(3) MFP factor (meat fish poultry factor，肉鱼禽因子)(4) Ca, Fe help each other to diminish the inhibitors3.2 absorption of heme iron(血红素铁)The absorption is not influenced by inhibitors which decrease the absorption of nonheme iron.3.3 absorption rate of iron in the fo
24、odsrice 1% corn 3% black bean 3% lettuce 4% flour 5% soybean 6% fish 11% hemoglobin 15% mustle, liver 22%4 iron-deficiency anemia4.1 iron-deficiency anemiaChina: 40% 0f children under 3 yWorld: 4y, 0.6%-7.7%5-8y, 5.5%young healthy women 35%-58%4.2 ReasonPoor dietsPoor absorptionBlood loss: menstruat
25、ion(月经), hemorrhage(出血), 0.5 mg Fe per ml blood.Pregnancy4.3 The process assessment of iron-deficiency anemia (IDA)first stage iron decrease(ID): stored iron exhaustion, serum ferritin.Second stage Iron-deficiency in erythrocytosis(红细胞生成缺铁期): serum Fe and ferritin, iron-biding capacity(saturation of
26、 transferrin,运铁蛋白饱和度), cons. 0f free erythrocyte protoporphyrin (FEP)(游离原扑啉) Third stage IDA: hemoglobin and hematocrite values decline.4.4 Deficiency symptomsImmune system: Reduced resistance to infection( lowered immunity) Nervous/Muscule systems: Reduced work productivity, tolerance to work; Redu
27、ced physical fitness(健康)Skin:itching(痒); pale nailbed(指甲床), eye membranes, and palm creases(掌心起皱 ); concave nails(凹面指甲); impaired wound healing(愈合).General:Reduced resistance to cold, inability to regulate body temperature, pica (clay eating, ice eating) （异食癖）5 DRIsmen: 15mg/d women: 20mg/dpregnancy
28、 25-35mg/d wet nurse 25mg/d6 Food sourceIodine （碘）1 Iodine in the body (20-50mg)tetraiodothyronine(T4), 16.2%(甲状腺素 )thyroid triiodothyronine(T3),7.6%(三碘甲状腺原氨酸 )iodine(8mg) diiodothyronine(DIT),33.4%(二碘酪氨酸 )monoiodothyronine(MIT),32.7%(一碘酪氨酸)othersIn blood: protein-binding iodine, 30-60g/L2. function
29、: thyroxin(T4)(甲状腺素)（1） regulating oxidation reactions in cells and energy metabolism.（2） Regulating protein synthesis by linking to the processes of genetic control in the nucleus.（3） Promoting the synthesis of cholesterol, intestinal absorption of carbohydrate and conversion of carotene to VitA.（4
30、） Regulating the metabolism of water and electrolyte.（5） Influencing the growth and development,and metal development.(15% mental retardation in ID area in china )3. absorption and metabolism 4. iodine deficiency IDD Adults: goiter Teenagers: influencing growth,development of body and mental. Infant
31、s: dementiaSupplement of iodide: iodized saltKI: 1:100000KIO3:1:20000500005.effects of excess iodine iodine goiter6.DRIsadults: 150ug/dpregnancy 175ug/dwet nurse 200ug/d UL 850ug/d7.dietary source: sea foodskelp 24mg/100g sea slug(海带) 0.6mg/100g mussel(淡菜) 1mg/100g laver(紫菜)1.8mg/100gZinc1. zinc in
32、the body(2-3g)肝、脾、肌肉、骨骼、眼中较多blood(900ug/100ml)found in all human prostate(前列腺)tissues (10-200ug/g) prostatic secretionsspermatozoa2. functions and zinc deficiency(1) essential constituent of over 100 enzymes,in each of the 6 major enzyme categories(2) Influencing growth, development and sexual syste
33、m. involving the synthesis of DNA,RNA protein(anorexia 厌食，failure to grow, testicular atrophy 睾丸萎缩,skin lesions )(3) Having normal appetite.(4) Promoting metabolism of Vit A.(5) Maintaining the reproduction of immune cells.(6) Involving in neoplastic processes.3. metabolism(shorten)4. DRIs and dieta
34、ry source(1) DRIs: (2) dietary source: seafoods and meats.Selenium1.Se in the bodyIn various amounts in all tissues of the body except fatBody size the highest concentration is in liver, heart,(14-20mg) kidney and spleenblood Se is 0.22ug/ml2.function and Se deficiency(1) a constituent of glutathion
35、e peroxidase(GSH-Px), antioxidant and anticancer.(2) Detoxification: heavy metals,AFB1.(3) Anticarcinogenic effect : skin,liver,colon,breast,etal.(4) Enhancement of humoral, cell-mediated and nonspecific immunity.(5)Maintain heart and cardiovascular structure and function (6)Keeping normal growth (7
36、)reducing free radical reaction and extending life span.3.toxicity:gastrointestional disturbances,bad teeth,yellow skin, cardiorenal disease.4.DRIs: 50ug/d5.food source: animal food and sea food.Se content of food depends on the soil in which the food was grown.Other elementsMg, Cu, Cr, Ni, Co, Mo,M
37、n,et al.(omit)第六节 维生素 Section 6 Vitamins一目的和要求1维生素 A，B1，B2，C 的性质、代谢、生理功能、缺乏病、营养学评价；食物来源和供给2了解维生素 D，E，烟酸等有关内容。3熟悉维生素 B6，叶酸等有关内容。 二重点和难点1重点：维生素 A，B1，B2；C 的有关内容2难点：维生素 A 的生理功能及机理。三、教学安排教学时数：1.5 学时四、教学方法重点讲授，复习、提问、讨论相结合。应用多媒体课件。五、授课内容 Preface1. definition(1)Are distributed in natural food stuffs but dis
38、tinct from the main components of food( proteins, et al) (quantity, energy, component of body).(2)Are essential for body metabolism in minute quantities and absence of any one of which causes a corresponding specific deficiency disease.(3)Can not be synthesized in the body except VitD.2. classificat
39、ion:(1)the order of discovery:A,B,C,D(2)function: ascorbic acid(3)chemical construction: popular (local) name: riboflavin(4)solubility: water-soluble:B,Cexcesses are excreted in the urine fat-soluble:A,Dlarge amount are toxic.3. deficiency of vitamins(1)cause: deficient intakes problem of absorption
40、 increase in requirement(2)deficiency: critical deficiency: disease marginal deficiency: influence health without symptoms维生素 A (VitA)retinal (A1)Vit A retinol s-dehydroretinal(A2)-carotene1. structures and properties:properties of VitA solubility: soluble in fats and all the usual organic solvents,
41、 insoluble in water. Oxidation: be oxidated by light,air and oxidant such as MnO2(Manganese dioxide). Isomerization(异构化 )：retinol is isomerized by light Stability:sensitive toward acids but stable to base. Color reaction: retinal and its esters have a yellowish-green fluorescence(荧光)。2. metabolism(1
42、) absorption: small intestine (2)transport and storage：插图(3)excretion 插图3. function(1)in vision: George Wald was awarded the Nobel Prize for medicine in 1967 for his discovery of the role of VitA in the visual system.插图(2)effect on cell membrance:regulating membrance structure and function by influe
43、ncing the biosynthesis of glycoprotein because VitA is headed for carrying mono-or oligosacchride units to an acceptor site.(3) Influencing the synthesis of bone and both serum and muscle proteins.it influence the growth,development and reproduction.(4) Against cancer: (-carotene is more important)4
44、. deficiency(1) night blindness and xerosis (干燥症) (2) xerosis occurs throughout the body (3) influencing the growth and development (especially bone,teeth)(4) others5. toxicity(1)infants: transient hydrocephalus(暂时脑积水)and vomiting.(2)Adult(chromic):20-30times of RDA.(3)osteoclasts activities increas
45、ing(4)others: fetus deformities, yellow skin, 6.estimation of nutritional level of VitA(1)VitA level in plasma: 0.350.70umol/L (1020ug/dL) deficiency.but normal level(30ug/dL)does not mean that VitA is enough.(2)VitA storage(3)RBP in plasma(4)Dark adaptation(5)Physiologic blind point7.DRIs and food
46、source(1) Units: 1IU VitA=0.3g RE1.0g Retinol=1.0g RE1.0g -carotene=0.167gRE(2) DRIs: Adults: 800g RE/d Pregnancy: 100g RE/d Wet nurse: 1200g RE/d(3) food source: -carotene:in plant:vegetable and fruits with pigments(色素):spinach(菠菜),carrot(胡萝卜),sweet potato(红薯), persimmon(柿), apricot( 杏),et al. VitA
47、:liver,egg,milk. Vit D (shortened)1. function(1) regulating plasma Ca and P with the parathyroid hormoneCa,P absorptionplasma Ca renal reabsorption plasma Ca,PCa from bone(2) facilitating(促进)mineralization of the bone.(3) Preventing ricket,osteomalacia(软骨病) and osteoporosis.2.DRIs and dietary source
48、Food source: same as VitA and sun light.Vit.E(tocopherol,生育酚)1. Function and deficiency(1) reproductive system: male:degeneration of seminiferous(生精) epithelium female: impairing vascular of fetal and placenta asphyxia (窒息) and death of fetus. No evidence to relate malfunction of the reproduction process in man.(2) muscular system:muscular dystrophy(肌肉营养不良)(3) nervous system cerebellar encephalomalacia (小脑软化症)(4) vascular system: hemorrhages, peroxide hemolysis (过氧化溶血)(5) biolodic antioxidant: keep the membrane stable(6) othe
