A lipid is a fatty substance found in living things. It is the science word that covers a whole group: the fat in your body, cooking oil, wax, cholesterol, and the thin fatty wall around every one of your cells.

A lipid脂質 is a fatty substance found in living things是生物體內含脂肪的物質。It is the science word that covers a whole group這是涵蓋一整群東西的科學用詞: the fat in your body你身體裡的脂肪, cooking oil食用油, wax蠟, cholesterol膽固醇, and the thin fatty wall around every one of your cells還有包住每個細胞的那層薄薄脂肪膜。

You will meet it in biology class, in a health report, or on a doctor's paper — 'blood lipids' means the fats floating in your blood, and a 'lipid profile' is the blood test that measures them. Almost always plural: lipids.

You will meet it in biology class你會在生物課, in a health report健檢報告, or on a doctor's paper或醫生的單子上遇到這個字 — 'blood lipids' means the fats floating in your blood「blood lipids」指的是浮在你血液裡的脂肪, and a 'lipid profile' is the blood test that measures them「lipid profile」則是測量這些脂肪的血液檢查。Almost always plural幾乎都用複數: lipidslipids。

It is not a word for the dinner table. Nobody says 'this pork has a lot of lipids'; they say fat.

It is not a word for the dinner table這不是餐桌上會用的字。Nobody says 'this pork has a lot of lipids'沒有人會說「這豬肉lipids很多」; they say fat大家會說fat。

The reason science needs a separate word is that 'fat' in ordinary English means the greasy stuff you can see and touch, while lipids include things that do not look fatty at all, like the wax on a leaf. What ties them together is that they do not mix with water — that is really the definition.

The reason science needs a separate word科學需要另外一個字的原因 is that 'fat' in ordinary English means the greasy stuff you can see and touch是因為一般英文的fat指的是看得到摸得到的油膩東西, while lipids include things that do not look fatty at all而lipids還包括完全不像脂肪的東西, like the wax on a leaf像葉子上的蠟。What ties them together把它們綁在一起的共同點 is that they do not mix with water是它們都不跟水混合 — that is really the definition這才是真正的定義。

Oil floating on top of soup is a lipid refusing to join the water, and that same refusing is exactly why your cell walls work: they keep the water outside out and the water inside in.

Oil floating on top of soup浮在湯上面的油 is a lipid refusing to join the water就是脂質拒絕跟水混在一起, and that same refusing is exactly why your cell walls work而同樣的這種「拒絕」正是細胞膜能運作的原因: they keep the water outside out and the water inside in讓外面的水留在外面,裡面的水留在裡面。