In this video we'll discuss carbohydrates
在这个视频中,我们将讨论碳水化合物·
A carbohydrate is an organic macromolecule which means it's a large molecule containing the element carbon
碳水化合物是一种有机大分子,这意味着它是一种包含碳元素的大分子·
The hydrate part of carbohydrates means it also contains the components of water hydrogen and oxygen
碳水化合物中 "水合物" 这部分意味着它还包含水的组成成分,即氢和氧·
Carbohydrates always contain these elements in a proportion of one carbon atom to two hydrogen atoms to one oxygen atom
碳水化合物总是按照一个碳原子、两个氢原子、一个氧原子这样的比例包含这些元素·
Think of it this way
可以这样来理解·
All carbohydrate molecules will always have an equal number of carbon and oxygen atoms and will also always have twice as many hydrogen atoms
所有碳水化合物分子中碳原子和氧原子的数量总是相等的,而且氢原子的数量总是它们的两倍·
So why are carbohydrates important
那么碳水化合物为什么重要呢?
Carbohydrates are the main fuel source from which all living things get their energy but carbohydrates don't always have the same overall structure
碳水化合物是所有生物获取能量的主要燃料来源,但碳水化合物并不总是具有相同的整体结构·
They are classified as either simple or complex based on their chemical structure
根据它们的化学结构,它们被分为简单碳水化合物和复杂碳水化合物·
All simple carbohydrates are sugars referred to as saccharides
所有简单碳水化合物都是糖类,被称作糖类化合物·
A saccharide can be made of one sugar molecule called a monosaccharide or two sugar molecules called a disaccharide
糖类化合物可以由一个糖分子组成,称作单糖,也可以由两个糖分子组成,称作双糖·
An example of a monosaccharide is the sugar glucose
单糖的一个例子就是葡萄糖这种糖类·
It's a monosaccharide because it's made of a single sugar molecule
它是单糖,因为它由一个糖分子构成·
Simple sugars like glucose are the quickest form of energy because your cells can break them down easily
像葡萄糖这样的单糖是最快的能量形式,因为你的细胞能够轻易地将它们分解·
Words ending in O S E or OSE are typically sugars such as the monosaccharides fructose galactose and dextrose
以 "O-S-E" 或 "OSE" 结尾的词通常是糖类,比如单糖中的果糖、半乳糖和右旋糖·
Like glucose these monosaccharides are all simple sugars because they are made up of a single sugar molecule
和葡萄糖一样,这些单糖都是简单糖类,因为它们都由一个糖分子组成·
When glucose and fructose are chemically bonded together we get a disaccharide called sucrose commonly known as table sugar
当葡萄糖和果糖通过化学键结合在一起时,我们就得到了一种双糖,叫做蔗糖,通常被称为食糖·
Sucrose is a disaccharide because it's made up of two monosaccharides
蔗糖是双糖,因为它由两个单糖组成·
Like monosaccharides disaccharides such as sucrose also end in O S E because they're sugar molecules
和单糖一样,像蔗糖这样的双糖也以 "O-S-E" 结尾,因为它们都是糖类分子·
Now let's talk about complex carbohydrates also known as polysaccharides
现在让我们来谈谈复杂碳水化合物,也被称作多糖·
Polysaccharides are very long chains of multiple monosaccharides chemically bonded together
多糖是由多个单糖通过化学键连接而成的很长的链状结构·
An entire polysaccharide is referred to as a polymer while each individual monosaccharide in this long chain is referred to as a monomer
整个多糖被称作聚合物,而这条长链中的每个单糖则被称作单体·
Examples of polysaccharides include cellulose starches and glycogen
多糖的例子包括纤维素、淀粉和糖原·
Cellulose is found in all plants
纤维素存在于所有植物中·
It's a structural carbohydrate that is found in the cell wall of every plant cell
它是一种结构性碳水化合物,存在于每个植物细胞的细胞壁中·
Starches are found in many of the foods we eat such as potatoes and corn
淀粉存在于我们吃的许多食物中,比如土豆和玉米·
Starches are also found in grains such as wheat and rice
淀粉也存在于像小麦和大米这样的谷物中·
The body's digestive system breaks down starches into glucose molecules to fuel the activities of all of our cells
人体的消化系统会将淀粉分解为葡萄糖分子,为我们所有细胞的活动提供能量·
Extra glucose molecules that the body doesn't immediately need for energy are stored as polysaccharides called glycogen either in the liver or in skeletal muscles
人体暂时不需要用于供能的多余葡萄糖分子会以一种叫做糖原的多糖形式储存在肝脏或骨骼肌中·
To sum up carbohydrates are organic macromolecules containing carbon hydrogen and oxygen in a one to two to one proportion
总而言之,碳水化合物是按照碳、氢、氧一比二比一的比例组成的有机大分子·
Carbohydrates are the main source of energy in living organisms
碳水化合物是生物体中的主要能量来源·
Carbohydrate monomers are simple sugars called monosaccharides
碳水化合物的单体是被称作单糖的简单糖类·
Disaccharides are two monosaccharides bonded together
双糖是由两个单糖结合在一起形成的·
Monosaccharide and disaccharide names typically end in OSE such as glucose fructose and sucrose
单糖和双糖的名称通常以 "OSE" 结尾,比如葡萄糖、果糖和蔗糖·
Carbohydrate polymers are called polysaccharides
碳水化合物的聚合物被称作多糖·
Polysaccharides include cellulose starches and glycogen
多糖包括纤维素、淀粉和糖原·
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