人類必需營養(yǎng)素

　　營養(yǎng)素是指食物中可給人體提供能量、構(gòu)成機(jī)體和組織修復(fù)以及具有生理調(diào)節(jié)功能的化學(xué)成分。學(xué)習(xí)啦小編為大家整理了人類必需營養(yǎng)素，希望對你有幫助哦!

　　A. Carbohydrates

　　Carbohydrates are the chief source of energy, containing carbon, hydrogen, and oxygen. It functions physically to provide energy, maintain regular activities of the heart and neurologic systems, protect liver from toxification and prevent ketosis.

　　A. 碳水化合物

　　碳水化合物是能量的主要來源，含有碳、氫、和氧等物質(zhì)。其重要生理功能為供給熱能、維持心臟和神經(jīng)系統(tǒng)的正?；顒?dòng)、保肝解毒、預(yù)防酮病。

　　Carbohydrates include sugars, starches, and cellulose. Simple sugars such as fruit sugar are easily digested. Starches are more complex and require more sophisticated enzyme processes to be reduced to glucose. Glucose is converted sugar or starch and appears in the body as blood sugar. Some glucose is processed by the liver, converted to glycogen, and stored by the liver for later use.

　　碳水化合物包括糖、淀粉和纖維素。單糖，如水果糖，易于消化;淀粉較為復(fù)雜，它通過酶解還原為葡萄糖;葡萄糖是糖或淀粉的轉(zhuǎn)化物，在機(jī)體內(nèi)則為血糖。有些葡萄糖經(jīng)肝臟處理轉(zhuǎn)化為肝糖并得以貯存?zhèn)溆谩?/p>

　　B. Fats

　　Fats or lipids are the second important nutrients next to carbohydrates. Fatty acids are the basic components of fat and can mainly be grouped into two: saturated fatty acids usually from animal sources and unsaturated fatty acids primarily from vegetables, nuts, or seed sources.

　　B. 脂肪

　　脂肪又叫脂質(zhì)，它僅次于碳水化合物的第二大營養(yǎng)素。脂肪酸是脂肪的基本成份，它可以分成兩大類：來源于動(dòng)物的飽和脂肪酸和來源于植物、堅(jiān)果或種子的不飽和脂肪酸。

　　C. Proteins

　　Proteins are complex organic compounds. They are digested and broken down to form 22 amino acids. Proteins are critical to all aspects of growth and development of body tissues and necessary for the building of muscles, blood, skin, internal organs, hormones, and enzymes. Protein is also a sources of energy. When there is insufficient carbohydrate or fat in the body, protein is burned to provide energy.

　　C. 蛋白質(zhì)

　　蛋白質(zhì)屬于復(fù)合有機(jī)物，經(jīng)消化分解，蛋白質(zhì)可以生產(chǎn)出22種氨基酸。蛋白質(zhì)對機(jī)體組織的生長發(fā)育至關(guān)重要，也是構(gòu)建肌肉、血液、皮膚、內(nèi)臟、激素和酶的必需物質(zhì)。蛋白質(zhì)也是熱能來源，當(dāng)體內(nèi)碳水化合物或脂肪不足時(shí)，就會通過燃燒蛋白質(zhì)來獲取熱能。

　　D. Vitamins

　　Vitamins are found only in living things. They usually cannot be synthesized by the human body. Vitamins can be grouped according to the substance in which they are soluble: fat-soluble and water-soluble. Vitamins A, D, E, and E are all fat-soluble while B-complex vitamins, vitamin C and the bioflavonoids water-soluble. Vitamins have no caloric value, but they are as necessary to the body as any other basic nutrients.

　　D. 維生素

　　維生素只存在于生命物體，通常不能由人體合成。按維生素的溶解環(huán)境，維生素可以分為兩大類：脂溶性和水溶性。維生素A、D、E和K為脂溶性維生素，B族維生素及維生素C和生物素屬于水溶維生素。維生素不提供熱量，但機(jī)體的重要性并不亞于其它基本營養(yǎng)素。

　　E. Water

　　Water is not specifically a nutrient. But it is essential for survival. Water is involved in every body process from digestion and absorption to excretion. It is a major portion of circulation and is the transporter of nutrients throughout the body.

　　E. 水

　　水并不是營養(yǎng)素，但水對生存必不可少。水參與了機(jī)體從消化吸收到排泄的全過程，是體內(nèi)循環(huán)的重要組成部分和體內(nèi)營養(yǎng)素的運(yùn)送者。

　　F. Minerals

　　Minerals form 60 –90 percent of all inorganic material in the body. They are found in bones, teeth, soft tissue, muscle, blood, and nerve cells and essential for metabolic processes. Minerals are grouped according to the amount found in the body: major minerals and trace minerals. The former includes sodium, potassium, calcium, magnesium, phosphorous and chlorine, all of which have a known function in the body. The latter includes iron, iodine, zinc, manganese, and copper. Their function in the body remains unclear.

　　F. 礦物質(zhì)

　　礦物質(zhì)占體內(nèi)無機(jī)材料的60-90%，骨、齒、軟組織、肌肉、血液、及神經(jīng)細(xì)胞中都有礦物質(zhì)，它是代謝過程的重要元素。根據(jù)體內(nèi)數(shù)量，礦物質(zhì)可分為兩類：常量礦物質(zhì)和微量元數(shù)。前者如鈉、鉀、鈣、鎂、磷和氯等，其在機(jī)體內(nèi)的作用從所共知;后者如鐵，碘、鋅、錳和銅等，對人體的作用尚不明了。