男友太凶猛1v1高h,大地资源在线资源免费观看 ,人妻少妇精品视频二区,极度sm残忍bdsm变态

您現在的位置: Language Tips> Easy English> Odd Question  
   
 





 
Why is some hair curly and some hair straight?
Why is some hair curly and some hair straight?
[ 2005-07-04 08:00 ]

Hair  
Why is some hair curly and some hair straight? Notes:
Why is some hair curly and some hair straight?Hair is curly or straight, depending upon the number of disulfide bonds between hair proteins found in thehair shaft.

The greater the number of links, the curlier the hair, and the fewer the number of links, the straighter the hair.

Hair is primarily composed ofkeratin, a protein, which grows from a sac called the follicle. Cells in the hair follicle generate keratin, and various other proteins, which become a part of the hair shaft. These proteins contain sulfur atoms, and when two of these sulfur atoms pair up and bond, they form a disulfide bond. If the two sulfur atoms in the same protein are at a distance, and join to form the disulfide bond, the protein will bend.

The amount of humidity in the air not only makes for what some label a "bad hair day," but alters the degree of curliness or of straightness of hair. This occurs when high humidity forces water back into the hair fiber, acts on its protein structure, and forces the hair shaft to return to its original structure.

People can temporarily alter their hair to force it into a straight state, or a curly state, but only on a temporary, not on a permanent, basis. When a straight-haired person gets a "permanent wave," known as a "perm,"he or she is chemically forcing the making of strong disulfide bonds. The wave does not stay permanently, because new hair, which is straight, grows in as the "perm" grows out. People with curly hair may chemically alter their hair to give it a straighter appearance, but this, too, is also a temporary solution to a permanent "problem," with the same end result.







毛干








角蛋白

 

 

 

 

 




燙發

中國日報網英語點津版權說明:凡注明來源為“中國日報網英語點津:XXX(署名)”的原創作品,除與中國日報網簽署英語點津內容授權協議的網站外,其他任何網站或單位未經允許不得非法盜鏈、轉載和使用,違者必究。如需使用,請與010-84883631聯系;凡本網注明“來源:XXX(非英語點津)”的作品,均轉載自其它媒體,目的在于傳播更多信息,其他媒體如需轉載,請與稿件來源方聯系,如產生任何問題與本網無關;本網所發布的歌曲、電影片段,版權歸原作者所有,僅供學習與研究,如果侵權,請提供版權證明,以便盡快刪除。
相關文章 Related Story
 
 
 
本頻道最新推薦
 
第63屆戛納電影節獲獎名單
Dorian Gray《道林·格雷》精講之一
'Grim situation' at Three Gorges Dam
為什么聽別人打手機會鬧心?
對口支援 partner assistance
翻吧推薦
 
論壇熱貼
 
關于工資的英語詞匯大全
關于職業裝的英語詞匯
余光中《尺素寸心》(節選)譯
中國譯協中譯英最新發布各類專業術語直譯
功夫熊貓經典臺詞雙語

 

主站蜘蛛池模板: 彭山县| 无锡市| 泰安市| 玉山县| 太和县| 寻甸| 永城市| 安徽省| 神木县| 陕西省| 宁阳县| 江川县| 平谷区| 林芝县| 敦化市| 安龙县| 富阳市| 县级市| 栖霞市| 孝感市| 三台县| 星座| 西丰县| 华安县| 阿拉善左旗| 镇巴县| 南宫市| 大埔县| 舒兰市| 中山市| 利川市| 融水| 犍为县| 香河县| 师宗县| 衡南县| 安康市| 辉县市| 怀化市| 浮山县| 广水市|