Lipids · 脂质
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| triglyceride/ˈtrɪɡlɪsəraɪd/ | 甘油三酯 | gān yóu sān zhǐ |
| glycerol/ˈɡlɪsərɒl/ | 甘油 | gān yóu |
| fatty acid/ˈfæti ˈæsɪd/ | 脂肪酸 | zhī fáng suān |
| ester bond/ˈestə bɒnd/ | 酯键 | zhǐ jiàn |
| hydrophobic/ˌhaɪdrəˈfəʊbɪk/ | 疏水 | shū shuǐ |
| saturated/ˈsætʃəreɪtɪd/ | 饱和 | bǎo hé |
| unsaturated/ʌnˈsætʃəreɪtɪd/ | 不饱和 | bù bǎo hé |
| phospholipid/ˈfɒsfəlɪpɪd/ | 磷脂 | lín zhī |
| bilayer/ˈbɪleɪə/ | 双层 | shuāng céng |
Energy stored, membranes built
- Lipids are the fats and oils — the body's long-term energy store.
- They do not mix with water, and that single fact explains what they do.
- One special lipid builds every cell membrane.
储存能量,构建膜
- 脂质是 脂肪和油——身体的长期能量储存。
- 它们不与水混合,这一个事实就解释了它们做什么。
- 一种特殊的脂质构建每一张细胞膜。
Triglycerides 甘油三酯
- A triglyceride is one glycerol 甘油 joined to three fatty acids 脂肪酸 by ester bonds 酯键 (each bond forms by condensation, so three waters are removed).
- It is non-polar and hydrophobic 疏水 — it will not mix with water.
- Fatty acids are saturated 饱和 (no C=C double bonds, straight, usually solid fats) or unsaturated 不饱和 (one or more double bonds, kinked, usually liquid oils).
A triglyceride: glycerol joined to three fatty acids by ester bonds
- Step through it below to watch the three ester bonds form.
甘油三酯
- 甘油三酯(triglyceride) 是一个 甘油(glycerol) 通过 酯键(ester bonds) 连接到 三个脂肪酸(fatty acids)(每个键通过缩合形成,所以移除三个水)。
- 它是 非极性的 且 疏水的(hydrophobic)——它不与水混合。
- 脂肪酸是 饱和的(saturated)(没有 C=C 双键,直,通常是固体脂肪)或 不饱和的(unsaturated)(一个或多个双键,弯折,通常是液体油)。
一个甘油三酯:甘油通过酯键连接到三个脂肪酸
- 在下面一步步走过去,观看三个酯键形成。
Building a triglyceride · 构建一个甘油三酯
Watch one glycerol join three fatty acids. Each ester bond forms by condensation, removing one water — three bonds, three waters. · 观看一个甘油连接三个脂肪酸。每个酯键通过缩合形成,移除一个水——三个键,三个水。
A triglyceride is made from: · 一个甘油三酯由以下构成:
A triglyceride = 1 glycerol + 3 fatty acids, joined by ester bonds (each forms by condensation). · 一个甘油三酯 = 1 个甘油 + 3 个脂肪酸,通过酯键连接(每个通过缩合形成)。
Glycerol joins each fatty acid by an ______ bond, formed by condensation. · 甘油通过一个 ______ 键连接每个脂肪酸,该键通过缩合形成。
Three ester bonds form, removing three water molecules in total. · 三个酯键形成,总共移除三个水分子。
Match each fatty acid type to its feature. · 把每种脂肪酸类型与它的特征配对。
Saturated chains have no C=C and pack tightly (solid); unsaturated chains kink at each C=C, so they stay liquid. · 饱和链没有 C=C 并紧密堆积(固体);不饱和链在每个 C=C 处弯折,所以它们保持液体。
Put the formation of a triglyceride in order. · 把一个甘油三酯的形成按顺序排列。
Each ester bond forms by condensation; three bonds release three water molecules. · 每个酯键通过缩合形成;三个键释放三个水分子。
Why fat is a great energy store
- It releases about twice the energy per gram as carbohydrate.
- It is insoluble, so it stays put and has no osmotic effect.
- It stores no extra water, so it adds little mass.
- Under the skin it also gives insulation and protects organs.
为什么脂肪是极好的能量储存
- 它每克释放约 两倍 于碳水化合物的能量。
- 它 不可溶,所以它待在原地,没有渗透作用。
- 它不储存额外的水,所以它增加的质量很少。
- 在皮肤下它还提供 隔热,并保护器官。
One reason triglycerides are good long-term energy stores is that they: · 甘油三酯是好的长期能量储存的一个原因是它们:
Lipids release ~2× the energy per gram of carbohydrate, are insoluble, and store no water. · 脂质每克释放约 2× 于碳水化合物的能量,不可溶,且不储存水。
Phospholipids 磷脂 and the bilayer 双层
- A phospholipid is a triglyceride with one fatty acid replaced by a phosphate group.
- This gives it two ends: a hydrophilic ("water-loving") polar phosphate head and two hydrophobic fatty-acid tails.
- In water the heads face out and the tails hide inside — forming the bilayer that makes every cell membrane.
Phospholipids line up with their water-loving heads out and water-hating tails in, forming a bilayer
磷脂和双层
- 磷脂(phospholipid) 是一个甘油三酯,其中一个脂肪酸被一个 磷酸(phosphate) 基团取代。
- 这给它两端:一个 亲水的(hydrophilic)(“爱水的”)极性 磷酸 头,和两个 疏水的 脂肪酸 尾。
- 在水中,头朝外,尾藏在里面——形成构成每一张细胞膜的 双层(bilayer)。
磷脂排列成亲水的头朝外、疏水的尾朝内,形成一个双层
A phospholipid forms membranes because it has: · 一个磷脂形成膜,因为它有:
The polar head is attracted to water and the non-polar tails avoid it, so phospholipids arrange into a bilayer. · 极性头被水吸引,非极性尾避开水,所以磷脂排列成一个双层。
In a phospholipid bilayer, the hydrophobic tails point inward and the hydrophilic heads face the water. · 在一个磷脂双层中,疏水的尾指向内,亲水的头朝向水。
Correct — heads face the watery surroundings on both sides; tails meet in the middle, away from water. · 正确——头朝向两侧含水的环境;尾在中间相遇,远离水。
You've got it
- triglyceride = 1 glycerol + 3 fatty acids joined by ester bonds (condensation)
- saturated = no C=C (solid fats); unsaturated = has C=C double bonds (liquid oils)
- great energy store: ~2× energy/gram, insoluble, no water, insulation
- phospholipid = hydrophilic head + hydrophobic tails → forms the membrane bilayer
你掌握了
- 甘油三酯 = 1 个 甘油 + 3 个 脂肪酸 通过 酯键 连接(缩合)
- 饱和 = 没有 C=C(固体脂肪);不饱和 = 有 C=C 双键(液体油)
- 极好的能量储存:~2× 能量/克、不可溶、没有水、隔热
- 磷脂 = 亲水的 头 + 疏水的 尾 → 形成膜的 双层