《营养学基础》PPT课件.ppt

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1、SECTION 5 MINERALS（矿物质）一、Introduction,Elements（元素）in human body,Total elements In human body is over 80.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:Ca,P,Na,K,Mg,S,Cl.,Function of minera

2、ls in body,1.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,二、钙（Calcium）,1.Distribution of Calcium in

3、 human body,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 in body,1)

4、.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 less

5、 rapidly.,Renewal,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,n

6、ormal 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)functio

7、n of the calcium content of the chyme(食糜).,Ca,P metabolism,2)Affecting factors,Age,children:75%0f ingested Ca;40%of food Ca adults:30%-60%;20%70y 1/3 of adults;15%,Sex,male female,Physiological situation,pregnancy and breast-feed others,Body Ca conc.,Dietary factors,increasing Ca absorption:Vit.D,La

8、ctose,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,3)Excretion,Fecal Ca:194 73 mg/d in the American men from unabs

9、orbed 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 plasma Ca,metabolic alkolosis(代谢性碱中毒),and diuretics(利尿剂

10、).,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 reabsorptionCalcitonin(降血钙素):inhibiting bone loss and increasing uri

11、ne Ca.Calmodulin(钙调节素):regulating the Ca in the cell.,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 this,about 200mg/day will be absorbed and 800mg/day excret

12、ed.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 reabsorbed.,4.DRIs of Ca,Estimation of DRIs（膳食参考摄入量）Infants

13、: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,5.Dietary source,milk,small shrimps(小虾),kelp(海带),legum

14、es(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）,三、Iron(铁),1.iron in Body,Body 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),Fe

15、rritin(铁蛋白)Hemosiderin(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%),Storage Fe(25%),iron in Body,2.Physiologic functions,(1)Important role in oxygen and electron transport Composition of hemoglobin and myoglobin:Oxygen trans

16、port.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 RBC,3.Absorption and Metabolism,Absorption,Fe3+Fe2+Food Fe,duodenum,Jejunum空,Ileum回,colon,Plasma iron(4mg)Fe3+transfer

17、rin(3540mg turned over/d),Storage Fe 300400mg R-E system,liver,spleen,bone marrow,Bone marrow 2025mg/d,hemoglosin,Hemoglobin catabolism,Urine,sweet,bile,feces(0.51mg/d),Transportation,Utilization and conservation,Storage,Hemorrhage RBC lost in urine,menstrual loss 0.31mg/d,All body cell,Death cells,

18、Desquamation(脱落)of cells,2025mg,Excretion,outline of iron metabolism in adult,Iron 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 Fe,Gastric juice pH4,Fe3+,Fe2+(Fe3+),Fe3+,Fe2+or c

19、helate,VitC,VitC,sugar,AA,stomach,Impaired abs in(achlorhydria and)gastrectomy,apoferritin,ferritin,Mucosal cell,transferrin,1-globulin,Fe2+,desquamation,Ingestion,Duodeum(major place),pH=7,Solubility of(Fe2+Fe3+),Absorption,Crypt at the base of villi,Fe,Transferrin,desquamation,villi,Blood accordin

20、g to need,Fe2+,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,factors of decreasing absorption,factors of increasing absorpt

21、ion iron dosage vit.C,B2;amino acids:cysteine(半胱氨酸)MFP factor(meat fish poultry factor，肉鱼禽因子)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,duodenum,cell,blood(transferring),The absorption of heme iron is not influ

22、enced 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,Poor diets Poor absorption Blood loss:menstruation(月经),hemorrhage(出血),0.5 mg Fe per ml bloo

23、d.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):stored iron exhaustion,serum ferritin.,2nd stage,Iron-deficiency in ery

24、throcytosis(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 symptoms,Immune system:Reduced resistance to infectionNervous/Muscular s

25、ystems 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 discrimination(识别力);Impaired reactivity and coordination(协调性)(infants).,Skin It

26、ching(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,the fingernails are a reflection of a persons state of health.Low l

27、evels of zinc and iron as well as thyroid problems can cause brittle nails.,Reticulocytes：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 they are mature.These slightly immature cells are called reticulocyt

28、es,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 easily treated with iron supplements.Anemia can cause low energy and fati

29、gue,and can lead to fatal haemorrhaging in women during childbirth.,Pakistan,5.DRIs,Men:15mg/d Women:20mg/d Pregnancy:25-35mg/d Wet nurse:25mg/d,Fe supplement in USA,6.Food source,常用食物中的铁含量(mg/100g食部),四、碘（Iodine）,tetraiodothyronine(T4),16.2%(甲状腺素)triiodothyronine(T3),7.6%(三碘甲状腺原氨酸)thyroid iodine(8mg

30、)diiodothyronine(DIT),33.4%(二碘酪氨酸)monoiodothyronine(MIT),32.7%(一碘酪氨酸)others In blood:protein-binding iodine(PBI),30-60 g/L,1.Iodine in the body(20-50mg),Structure of T4 and T3,regulating oxidation reactions in cells and energy metabolism.Regulating protein synthesis by linking to the processes of ge

31、netic control in the nucleus.Promoting the synthesis of cholesterol,intestinal absorption of carbohydrate and conversion of carotene to VitA.Regulating the metabolism of water and electrolyte.Influencing the growth and development,and mental development.(15%mental retardation in ID area in china),2.

32、Function of iodine in body,colloid,TG:thyroglobulin甲状腺球蛋白,3.absorption and metabolism,Thyroid gland,TG,T4,T3,DIT,MIT(d)(c),T4,T3,Dietary iodine,肝中合成 葡萄糖酸酯或硫酸酯,Fecal iodine 10%,I-,T4 bound/free,T3,T3 T4,Effect,Urinary iodine 90%,Sweet and milk,Target cells,(g)bile,(a),(b),(e),(f),(h),a:absorption die

33、tary iodine is converted to inorganic form(iodine)and 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 a

34、nd some excreted into the bile.h:tissues convert T4 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 KIO3:1:2000

35、050000,5.effects of excess iodine iodine goiter,6.DRIs,Adults 150ug/d Pregnancy 175ug/d Wet nurse 200ug/d 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（Zinc）,1.zinc in the body(2-3g),found in all human tissues(10-200ug/g),Mo

36、re in liver,spleen,heart,muscle,bone,eye,and skin,blood(900ug/100ml),prostate(前列腺),prostatic secretions,Spermatozoa（精液）,2.Functions and zinc deficiency,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）a

37、nd ligase（连接）.(2)Influencing growth,development and 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 ne

38、oplastic（瘤的）processes.,2.Functions and zinc deficiency,Zinc finger,3.Metabolism(shorten)4.Deficiency and Toxicity,5.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 body,Body size(14-20mg),In various

39、amounts in all tissues of the body except fat,the highest concentration 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:

40、skin,liver,colon,breast,et al.4).Enhancement of humoral,cell-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 lif

41、e span.,Incidence of Cancer in Placebo and Se Treated Subjects,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 wh

42、ich the food was grown.,Section 6 VitaminsPreface,1.Common properties,Distributed in natural food stuffs but distinct from the main components of food(proteins,et al)(quantity,energy,component of body).Eessential for body metabolism(coenzyme,or prosthetic group辅基)in minute quantities and absence of

43、any one of which causes a corresponding specific deficiency disease.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

44、in the urine fat-soluble:A,Dlarge amount are toxic.,3.Deficiency of vitamins,(1)Cause:,deficient intakes problem of absorption increase in requirement,(2)Deficiency:,critical deficiency:disease marginal deficiency:influence health without symptoms,一、Vit A,retinal(A1),s-dehydroretinal(A2),retinol,-ca

45、rotene,1.structures and properties:,structure,A1,A2(biopotency of A2 is 40%that of A1),Trans configuration,Cis configuration,-carotene(provitamin A),-carotene,-carotene,solubility:soluble in fats and all the usual organic solvents,insoluble in water.Oxidation:be oxidized by light,air and oxidant suc

46、h 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)。Acid reagents give blue color or purple(sulfuric acid)reaction with Vit.A,Properties of Vit

47、.A,2.Metabolism,absorption:,-carotene,retinal,small intestine,(水解)1/3(fat,bile acid),retinyl ester,upper intestine,retinol,mucosal cell wall,Esterifiedchylomicron,mucosal cell,(水解),（还原）,from-carotene,mucosal cell,(2)Transport and storage,retinyl esters,lymphatic system,blood scream,storage,liver(90%

48、)Kidney Lung,eye,free retinal,blood scream,Tissue for metabolic requirement,水解,chylomicron,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).

49、Excretion,Vit.AIn liver,Vit.AGlucaronides(葡萄糖苷酸),blie,Reabsorbed,Excreted with feces,liver,Vit.AIn tissues,Methylated metabolites,urine,3.Function,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,+p

50、rotein,+ospin,Iodopsin(蓝),Rhodopsin（红）,High light,Dim light,All-trans retinal,+protein,Producing a nervous exitation,brain,Visual sensations,Some of all trans-retinal,Dark adaptation,(2)Effect on cell membrance:regulating membrance structure and function by influencing the biosynthesis of glycoprote