首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Nutrients are the parts of food that are important for life and health. Nutrients are important for three reasons. First, some n
Nutrients are the parts of food that are important for life and health. Nutrients are important for three reasons. First, some n
admin
2013-01-10
23
问题
Nutrients are the parts of food that are important for life and health. Nutrients are important for three reasons. First, some nutrients provide fuel for energy. Second, some nutrients build and repair body tissues. Third, some nutrients help control different processes of the body like the absorption of minerals and the clotting of blood. Scientists think there are 40 to 50 nutrients. These nutrients are divided into five general groups: carbohydrates, fats, proteins, minerals, and vitamins.
The first group of nutrients is carbohydrates. There are two kinds of carbohydrates: starches and sugars. Bread, potatoes, and rice are starches. They have many carbohydrates. Candy, soft drinks, jelly, and other foods with sugar also have carbohydrates. Carbohydrates are important because they provide the body with heat and energy. Sugar, for instance, is 100 percent energy. It has no other food value. Sugar does not build body tissues or control body processes. If there are too many carbohydrates in the body, they are stored as body fat. The body stores fuel as fat.
There are two types of fats: animal and vegetable. Butter, cream, and the fat in bacon are animal fats. Olive oil, corn oil, and peanut oil are vegetable fats. The body has fat under the skin and around some of the organs inside. The average adult has 10 to 11 kilograms (20 to 25 pounds) of body fat. If adults eat too many carbohydrate and fats, they can add another 45 kilograms (100 pounds) to their bodies. Fat is extra fuel. When the body needs energy, it changes the fat into carbohydrates. The carbohydrates are used for energy. Fat also keeps the body warm.
The third group of nutrients is proteins. The word "protein" comes from a Greek word that means "of first importance". Proteins are "of first importance" because they are necessary for life. Proteins are made of amino acids, which build and repair body tissue. They are an important part of all the muscles, organs, skin, and hair. The body has 22 different amino acids. Nutritionists call eight of these amino acids essential because the body does not manufacture them.
There are two kinds of proteins: complete proteins and incomplete proteins. Complete proteins, which the body needs for growth, have all the essential amino acids. Meat, fish, poultry, eggs, milk, and cheese have complete proteins. The body needs complete proteins every day. Incomplete proteins do not have all the essential amino acids. The proteins in vegetables and grains, for instance, are incomplete proteins. Two ways to form complete proteins from incomplete proteins are: (1) to mix vegetables and grains correctly, or (2) to add a small amount of meat or milk to a large amount of grains. The body can then use the complete proteins which result from the mixtures.
Extra protein in the body can be changed to fat and stored as body fat. It can also be changed to carbohydrates and used for energy. If people do not eat enough carbohydrates and fats for the energy that they need, their body uses proteins for energy. Then the body does not have the proteins that it needs to build and repair tissues. A nutritious diet includes carbohydrates and fats for energy, and proteins for growth.
Among those______.has more value than any other nutrient.
选项
A、vitamins
B、protein
C、minerals
D、fat
答案
B
解析
文中第四段说“Proteins are offirst importance”,可见蛋白质比其他营养物质更重要,因此B项为正确答案。
转载请注明原文地址:https://kaotiyun.com/show/KZTO777K
0
研究生英语学位课统考(GET)
相关试题推荐
Ifyoualways______peoplewon’tbelievewhatyousay.
Planningisaveryimportantactivityinourlivesyetreallysophisticated.Itcangivepleasure,evenexcitement,【C1】______ca
Planningisaveryimportantactivityinourlivesyetreallysophisticated.Itcangivepleasure,evenexcitement,【C1】______ca
WhatistheClassicalTheoryoftheRateofinterest?Itissomething【C1】______wehaveallbeen【C2】______andwhichwehaveaccep
Ourlivesarewoventogether.AsmuchasIenjoymyown【C1】______,InolongerimagineIcangetthroughasingledaycompletely
Ourlivesarewoventogether.AsmuchasIenjoymyown【C1】______,InolongerimagineIcangetthroughasingledaycompletely
Anupsurgeofnewresearchsuggestsanimalshaveamuchhigherlevelofbrainpowerthanpreviousthought.Beforedefininganimal
Thelong,wetsummerhereinthenortheasternU.S.notwithstanding,there’saworldshortageofpure,freshwater.Asdemandfor
Customersmayalsobepermittedto______theircurrentaccountsforashortperiodinanticipationofacredititemcomingin.
随机试题
通过阻断介导复极的钾通道而延长心脏动作电位时程,从而增加心肌组织的不应期,脂溶性高,口服、静脉注射均可的抗心律失常药是()。
砖夹的宽度为0.25m,曲杆ACB与GCED在G点铰接,尺寸如图所示。设砖重P=120N,提起砖的力F作用在砖夹的中心线上,砖夹与砖间的摩擦系数fs=0.5,为了把砖夹起距离b的范围为()。
简要说明当代教育学的发展趋势。
我国现阶段确立劳动、资本、技术和管理等生产要素按贡献参与分配的原则有利于()。
在四年级的数学课上,教师要求学生用三角尺画一组平行线,这时有同学告状说同桌抢走了他的三角尺,同桌却反驳说没有。作为教师,恰当的做法是:
剑拔弩张:一触即发
Woman:DidyouwatchourProfessorStilleronTVlastnight?Man:Ialmostmissedit!Butmymotherjusthappenedtobewatching
汇票
下列关于期间的计算方法,不正确的一项是()
•Youwillheartheorganiserofanannualconferenceattendedbythesalesrepresentativesofalargecompany.Heistellingth
最新回复
(
0
)