第二章营养学基础2课件.ppt

1、SECTION 5 MINERALS（矿物质）（矿物质）一、一、Introduction ElementsElements（元素）（元素）in human bodyin human body 1.Total elements In human body is over 80.2.Essential elements in human body over 20,most of them(about 20)are mineral elements Microelements:Fe,Zn,Se,I,Cu,Co,Cr,F,Mn,Minerals Mo,Si,Ni,B,V.Macroelements:C

2、a,P,Na,K,Mg,S,Cl.FunctionFunction of minerals in body1.Composition of human body.2.Maintain the pH and osmotic pressure(渗透压)of body liquids.3.Regulating the exciting of nerve and muscle.4.Components of prosthetic group(辅基),hormone,vitamin,protein,nucleic acid,and activator（激活剂）of enzyme.5.The others

3、 二、钙（二、钙（CalciumCalcium）Ca in the body:850-1200g 1.5%-2.0%of body weight Bone,teeth,99%:Hydroxyapatite（羟磷灰石）amorphous Ca（未定形钙）Combined form,0.5%:combined with protein and citric acid（柠檬酸）Ion,0.5%：Miscible Ca Pool（混溶钙池）In blood,extra-cellular fluid,soft tissue,and exchangeable.2.Function of calcium i

4、n body1).Principal component of skeletal tissue Osteoblasts(成)Osteoclasts(破)Bone Ca(miscible Ca pool)Children:1-2 year Adult:10-12 y(2%-4%per year,700mg/d)After 40y:Ca in the bone decreased by 1%per year Earlier in females than in males;Most rapidly during first 3 years After menopause;Taller people

5、 less rapidly.2).Regulating neuromuscular(神经肌肉)excitability,maintaining transmission of nerve impulses (神经冲动)and heart beats.(3)Influencing enzymereaction:Succinodehydrogenase(琥珀酸 脱氢酶).Lipase(脂肪酶),ATPase(三磷酸腺苷酶),proteinase(蛋白酶),(4)Others:hormone secretion,blood coagulation(凝结),acid-base balance,norm

6、al colloid(胶体).3.Absorption and Metabolism 1)Mechanism of absorption:Position:in the small intestine Transcellular(跨细胞):saturable(可饱和的)(active)transfer that involves a calcium-biding protein,calbindin(钙结合蛋白).Paracellular(同细胞水平):a nonsaturable (diffusional 扩散)transfer that is a linear(一维的)function of

7、 the calcium content of the chyme(食糜).Ca,P metabolism2)Affecting factors Age children:75%0f ingested Ca;40%of food Ca adults:30%-60%;20%70y 1/3 of adults;female Physiological situation pregnancy and breast-feed others Body Ca conc.Dietary factorsDietary factors increasing Ca absorption:Vit.D,Lactose

8、,Some amino acids:Arginine(精氨酸),lysine(赖氨酸)decreasing Ca absorption :phytate(植酸盐),oxalate(草酸盐),fibre,fatty acid,alcohol;thyroid hormone(甲状 腺素),cortisol(皮质醇),and antibiotics:penicillin,chloramphenical(氯霉素),neomycin(新霉素)膳食成分对钙吸收利用的影响提高吸收利用乳糖某些氨基酸Vit D降低吸收利用植酸盐膳食纤维草酸盐脂肪（脂肪泻时）乙醇无作用磷蛋白质Vit C柠檬酸果胶3)Excret

9、ion Fecal Ca:194 73 mg/d in the American men from unabsorbed Ca and endogenous(内源性)CaUrine Ca:diets containing 600-800 mg/d ranges between 80-250mg in urine.Sweat Ca:20-30mg/d;1g/d at high temp.Milk Ca:150-300mg/d Renal tubular reabsorption of Ca is increased by parathyroid hormone(甲状旁腺素),a fall in

10、plasma Ca,metabolic alkolosis(代谢性碱中毒),and diuretics(利尿剂).Increased by saline diureses(含盐多尿症),carbohydrate ingestion,phosphate deprivation(丧失),metabolic acidosis(代谢性酸中毒),cortisal,thyroid and growth hormones,diets rich in protein and magnesium(镁).fecal Vit.D and parathyin(甲状旁 腺素):renal reabsorption Ca

11、lcitonin(降血钙素):inhibiting bone loss and increasing urine Ca.Calmodulin(钙调节素):regulating the Ca in the cell.4)Biologic control system for homeostasis (体内平衡)of Ca.ECF:Extracellular fluid Calcium balance On average,in a typical adult approximately 1g of elemental calcium(Ca2+)is ingested per day.Of thi

12、s,about 200mg/day will be absorbed and 800mg/day excreted.Approximately 1kg of(Ca2+)is stored in bone and about 500mg/day is released by resorption or deposited during bone formation.Of the 10g of(Ca2+)filtered through the kidney per day only about 200mg appears in the urine,the remainder being reab

13、sorbed.4.DRIs of Ca(1)Estimation of DRIs（膳食参考摄入量）Infants:mean intake of breast milk(母乳)Others:Ca balance test(平衡试验)Direct measure(2)DRIs(mg/d)y:0 0.5 1 4 11 18 50AI:300 400 600 800 1000 800 1000 Y:pregnant women wet nurse（乳母）AI:1000(中期)1200(晚期)1200UL(tolerable upper intake level,):2000mgNOAEL:1500mg

14、5.Dietary source milk,small shrimps(小虾),kelp(海带),legumes(豆类):soy bean、black soy bean(黑豆),red bean(红豆),sesame paste(芝麻酱),and many Ca supplements(钙补充剂).常用食物中的钙含量（mg/100g食部）名称人 奶牛 奶奶 酪蛋 黄标准粉标准米虾 皮猪肉(瘦)牛肉(瘦)羊肉(瘦)鸡肉(瘦)含钙量34120590134241020001161311名称海带(干)发 菜银 耳木 耳紫 菜大 豆豆腐丝豆 腐青 豆豇 豆豌 豆含钙量117776738035734336

15、728424027724010084名称蚕 豆腐 竹花生仁杏仁(生)西瓜子(炒)南瓜子(炒)核桃仁小白菜大白菜油 菜韭 菜含钙量93280671402372351199316361140105三、三、Iron(Iron(铁铁)1.iron in BodyBody iron(4-5g)Hemoglobin(血红蛋白)(60%-75%)Myoglobin(肌红蛋白)(3%)Heme enzymes(含铁酶)Cytochromes(细胞色素)Cytochrome oxidase(细胞色素氧化 酶)Peroxidase (过氧化物酶)Catalase (过氧化氢酶)Ferritin(铁蛋白)Hemos

16、iderin(含铁血黄素)4 mg as transport iron bound to transferrin(运铁蛋白)in the plasma.No free ion of iron in the body.Functional Fe(75%)Functional Fe(75%)Storage Fe(25%)Storage Fe(25%)iron in Body2.Physiologic functions(1)Important role in oxygen and electron transport Composition of hemoglobin and myoglobin:

17、Oxygen transport.Composition of enzymes:electron transport.(2)Others:Catalyzing-carotene Vit.A;Promoting produce of antibody;Lipids transport in blood;Detoxifying（去毒）:drugs in liver Kidney and RBC3.Absorption and Metabolism AbsorptionFe3+Fe2+Food Fe duodenumJejunum空Ileum回colon Plasma iron (4mg)Fe3+t

18、ransferrin (3540mg turned over/d)Storage Fe 300400mg R-E system,liver,spleen,bone marrowBone marrow 2025mg/dhemoglosinHemoglobin catabolismUrine,sweet,bile,feces(0.51mg/d)TransportationUtilization and conservationStorageHemorrhage RBC lost in urine,menstrual loss 0.31mg/dAll body cellDeath cellsDesq

19、uamation(脱落)of cells2025mgExcretion outline of iron metabolism in adultIron absorption and metabolism Human unable to excrete excess iron.Iron balance physiologically regulated by control of absorption 1)Absorption of nonheme iron(非血红素铁)Food FeGastric juice pH=7Solubility of(Fe2+Fe3+)AbsorptionCrypt

20、 at the base of villiFeTransferrindesquamationvilliBlood according to needFe2+rapid transit time in GI chylia(胃液缺乏),malabsorption syndromes precipitation(沉淀)by alkalinization(碱化),phosphates phytates(植酸),oxalate(草酸)and antacids(抗酸剂)iron dosage male:A0.022D female:A0.025D A:iron absorbed D:Iron dosage

21、 factors of decreasing absorptionfactors of increasing absorption v iron dosage v vit.C,B2;amino acids:cysteine(半胱氨酸)v MFP factor(meat fish poultry factor，肉鱼禽因子)v Ca,Fe help each other to diminish the inhibitors；Zn,Fe have competitive absorption.2)absorption of heme iron(血红素铁)heme iron enzyme duoden

22、um cell blood(transferring)The absorption of heme iron is not influenced by inhibitors which decrease the absorption of nonheme iron.3)absorption rate of iron in the foods rice 1%corn 3%black bean 3%lettuce 4%flour 5%soybean 6%fish 11%hemoglobin 15%mustle,liver 22%2)Reason v Poor dietsv Poor absorpt

23、ion v Blood loss:menstruation(月经),hemorrhage(出血),0.5 mg Fe per ml blood.v Pregnancy 1)Prevalence of IDA China:40%0f children under 3 y World:4y,0.6%-7.7%5-8y,5.5%young healthy women，35%-58%4.iron-deficiency anemia(IDA)Prevalence of anemia 3)The process assessment of IDA 1st stage iron decrease(ID):s

24、tored iron exhaustion,serum ferritin.2nd stage Iron-deficiency in erythrocytosis(红细胞生成缺铁期):serum Fe and ferritin,iron-biding capacity(saturation of transferrin,运铁蛋白饱和度),cons.of free erythrocyte protoporphyrin(FEP)(游离原扑啉)3rd stage IDA:hemoglobin and hematocrite(红细胞压积)values decline.4)Deficiency sympt

25、oms Immune system:Reduced resistance to infectionNervous/Muscular systems Reduced work productivity,tolerance to work;Reduced physical fitness(健康):weakness,fatigue(疲劳);Impaired cognitive function（损害认识功能）(children);Reduced learning ability;Increased distractibility (注意力分散);Impaired visual discriminat

26、ion(识别力);Impaired reactivity and coordination(协调性)(infants).Skin Itching(痒);pale nailbed(指甲床)and eye membranes;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）Like the skin,th

27、e fingernails are a reflection of a persons state of health.Low levels of zinc and iron as well as thyroid problems can cause brittle nails.Reticulocytes：网状细胞：网状细胞 In the presence of some anemias,the body increases production of red blood cells(RBCs),and sends these cells into the bloodstream before

28、 they are mature.These slightly immature cells are called reticulocytes,and are characterized by a network of filaments and granules.Reticulocytes normally make up 1%of the total RBC count,but may exceed levels of 4%when compensating for anemia.Checking for anemia(iron deficiency),which can be easil

29、y treated with iron supplements.Anemia can cause low energy and fatigue,and can lead to fatal haemorrhaging in women during childbirth.Pakistan 5.DRIs v Men:15mg/d v Women:20mg/d v Pregnancy:25-35mg/dv Wet nurse:25mg/d Fe supplement in USA6.Food source 常用食物中的铁含量(mg/100g食部)食物稻 米标准粉小 米 玉米(鲜)大 豆红小豆绿 豆芝

30、麻酱含铁量2.33.55.11.18.27.46.558.0食物 黑木耳(干)猪肉(瘦)猪肝 鸡肝 鸡蛋 虾米 海带(干)带鱼含铁量97.43.022.68.22.011.04.71.2食物 芹 菜 打油菜 大白菜 菠 菜 干红枣 葡萄干 核桃仁 桂 圆含铁量0.87.04.42.51.60.43.544.0四、碘四、碘 （Iodine Iodine）tetraiodothyronine(T4),16.2%(甲状腺素)triiodothyronine(T3),7.6%(三碘甲状腺原氨酸)thyroid iodine (8mg)diiodothyronine(DIT),33.4%(二碘酪氨酸)m

31、onoiodothyronine(MIT),32.7%(一碘酪氨酸)others In blood:protein-binding iodine(PBI),30-60 g/L1.Iodine in the body(20-50mg)Structure of T4 and T3(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)

32、Promoting the synthesis of cholesterol,intestinal absorption of carbohydrate and conversion of carotene to VitA.(4)Regulating the metabolism of water and electrolyte.(5)Influencing the growth and development,and mental development.(15%mental retardation in ID area in china)2.Function of iodine in bo

33、dy colloidTG:thyroglobulin甲状腺球蛋白3.absorption and metabolism Thyroid glandTGT4T3DITMIT(d)(c)T4T3Dietary iodine肝中合成 葡萄糖酸酯或硫酸酯Fecal iodine 10%I-T4 bound/freeT3T3 T4EffectUrinary iodine 90%Sweet and milkTarget cells(g)bile(a)(b)(e)(f)(h)a:absorption dietary iodine is converted to inorganic form(iodine)a

34、nd rapidly absorbed from the gastrointestinal tract.b,c:circulating iodine is ether excreted into the urine or taken up by the thyroid gland.d,e:the pathway of T3,T4 synthesis.f:secretion of T4 and T3 into the blood.g:some of T4 is converted to T3 and some excreted into the bile.h:tissues convert T4

35、 to T3 and some of T3 is returned to the circulating in many tissues.4.iodine deficiency IDD Adults:goiter（甲状腺肿）Teenagers:influencing rowth,development of body and mental.Infants:dementia（痴呆）Supplement of iodide:iodized salt KI:1:100000 KIO3:1:2000050000 5.effects of excess iodine iodine goiter 6.DR

36、Is Adults 150ug/d Pregnancy 175ug/d Wet nurse 200ug/d v UL 850ug/d 7.Dietary source:sea foods kelp(海带)24mg/100g，sea slug（海参）0.6mg/100g，mussel(淡菜)1mg/100g，laver(紫菜)1.8mg/100g 五、锌（五、锌（Zinc）1.zinc in the body(2-3g)found in all human tissues(10-200ug/g)More in liver,spleen,heart,muscle,bone,eye,and skin

37、blood(900ug/100ml)prostate(前列腺)prostatic secretions Spermatozoa（精液）2.Functions and zinc deficiency(1)Essential constituent of over 100 enzymes,in each of the 6 major enzyme categories:oxidoreductase,transferase,hydrolase(水解)，lyase（裂合）,isomerase（异构）and ligase（连接）.(2)Influencing growth,development and

38、 sexual system.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（瘤的）processes.2.Functions and zinc deficienc

39、y Zinc finger 3.Metabolism(shorten)4.Deficiency and Toxicity5.DRIs and dietary source 1)DRIs:1-9 y:10mg/d 10y:15mg/d pregnant and wet nurse:20mg/d 2)Dietary source:seafoods and meats.六、硒（Selenium）1.Se in the bodyBody size(14-20mg)In various amounts in all tissues of the body except fat the highest c

40、oncentration is in liver,heart,kidney and spleen blood Se is 0.22ug/ml 2.Function and Se deficiency 1).A constituent of glutathione peroxidase(GSH-Px),antioxidant and anticancer.2).Detoxification:heavy metals,AFB1.3).Anticarcinogenic effect:skin,liver,colon,breast,et al.4).Enhancement of humoral,cel

41、l-mediated andnonspecific immunity.5).Maintain heart and cardiovascular structure and function Keshan.6).Keeping normal growth:impairment of growth,sparse(稀少)hair,cataracts(白内障),et al.7).Reducing free radical reaction（自由基反应）and extending life span.Incidence of Cancer in Placebo and Se Treated Subjec

42、ts 3.Toxicity:gastrointestional disturbances,bad teeth,yellow skin,cardiorenal disease,loss of hair and nails,nervous system disorders et al.4.DRIs:50ug/d 5.food source:animal food and sea food.Se content of food depends on the soil in which the food was grown.Section 6 VitaminsPreface 1.Common prop

43、erties(1)Distributed in natural food stuffs but distinct from the main components of food(proteins,et al)(quantity,energy,component of body).(2)Eessential for body metabolism(coenzyme,or prosthetic group辅基)in minute quantities and absence of any one of which causes a corresponding specific deficienc

44、y disease.(3)Can not be synthesized in the body except VitD.2.Classification:(1)the order of discovery:A,B,C,D(2)function:ascorbic acid(3)chemical construction:popular(local)name:riboflavin(4)solubility:water-soluble:Bs,Cexcesses are excreted in the urine fat-soluble:A,Dlarge amount are toxic.3.Defi

45、ciency of vitamins(1)Cause:deficient intakes problem of absorption increase in requirement(2)Deficiency:critical deficiency:disease marginal deficiency:influence health without symptoms 一、一、Vit A retinal(A1)s-dehydroretinal(A2)retinol-carotene 1.structures and properties:structureA1A2(biopotency of

46、A2 is 40%that of A1)Trans configuration Cis configuration-carotene(provitamin A)-carotene -carotenesolubility:soluble in fats and all the usual organic solvents,insoluble in water.Oxidation:be oxidized by light,air and oxidant such as MnO2(Manganese dioxide).Isomerization(异构化)：retinol is isomerized

47、by light Stability:sensitive toward acids but stable to base.Color reaction:retinal and its esters have a yellowish-green fluorescence(荧光)。Acid reagents give blue color or purple(sulfuric acid)reaction with Vit.A Properties of Vit.A 2.Metabolism(1)absorption:-carotene retinal small intestine(水解)1/3(

48、fat,bile acid)retinyl esterupper intestineretinolmucosal cell wallEsterifiedchylomicronmucosal cell(水解)（还原）from -carotene mucosal cell(2)Transport and storageretinyl esterslymphatic systemblood screamstorageliver(90%)Kidney Lung ,eyefree retinalblood screamTissue for metabolic requirement水解chylomicr

49、on The blood level of Vit.A is independent of the liver reserve.Retinol is transported in plasma in association with a specific transport Protein RBP:Vit.A level in plasm is proportional to the level of RBP.(3).ExcretionVit.AIn liverVit.AGlucaronides(葡萄糖苷酸)blieReabsorbed Excreted with fecesliverVit.

50、AIn tissuesMethylated metabolitesurine3.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.Retinal 11-cis form+protein+ospinIodopsin(蓝)Rhodopsin（红）High lightDim lightAll-trans retinal+proteinProducing a nervous