And some chemical breakdown continues in the large intestine, thanks to our little bacterial farm there.

多亏了我们那里小细菌农场，一些学分解在大肠中继续。

Plastics can take hundreds of years to degrade, or break down chemically.

塑料可能需要数百年才能降解或学分解。

As chemical pollutants break down and sink into the earth, rivers become cleaner.

随着学污染物分解并沉入地下，河流变得更加清洁。

This process of using oxygen to break down sugars into chemical energy is called cellular respiration.

线粒体利用氧气把糖分分解成学能过程叫做细胞呼吸。

No. They take hundreds of years to decompose – or break down by natural chemical processes.

不是。是因为它们分解要需要几百年时间。降解是指通过自然学反应分解过程。

They can change their diets so there are fewer of the precursor chemicals that get broken down into trimethylamine.

他们可以通过改变饮食来减少学品摄入，而这种学品会分解成为三甲胺。

And outside of being bitter, it's considered unreactive, so it's basically non-toxic and isn't destroyed by water or most other chemicals.

它被认为是惰性物质，因此基本上无毒，也不会溶于水或被大部分其他学物质所分解。

Now we don't usually think of it this way, but that is where digestion starts — the mechanical and chemical breakdown of food through chewing and enzyme-action.

我们通常不这么想，但消是从这里开始——通过咀嚼和酶作用对食物进行机械和学分解。

While breaking down chemicals for energy is nice and all, early life did miss out on the greatest available source of energy: The Sun.

虽然分解学物质能源是一件很好事，早期生命确实错过了最大可用能源：太阳。

With most cases, the macrophage then fuses the phagosome with a lysosome which has hydrolytic enzymes that can pretty much break down any biochemical molecules.

大部分情况下，巨噬细胞会将吞噬小体和溶酶体融合到一起；溶酶体中含有水解酶可以很大程度上分解生物学分子。

Then, a little chemistry knocked the acid off, creating what was clearly an alkene, so they named it benzene, because it was an alkene that was from the benzoin resin.

然后，用一点学方法将酸分解， 产生明显是烯烃物质， 因此他们将其命名为苯，因为它是一种来自安息香树脂烯烃。

Moving through the digestive tract - down the esophagus, into the stomach, ending up in the small intestine food is chemically broken down into smaller molecules, and nutrients are absorbed into the body.

穿过消道-沿着食道进入胃部，最后进入小肠食物被学分解成较小分子，营养物质被吸收到体内。

That's why molecular substances like ice and water can be physically broken or separated into portions, while only a chemical reaction can break apart the molecules themselves, like how water can be split into hydrogen and oxygen using electricity.

这就是为什么像冰和水这样分子物质可以物理破碎或分成几部分，而只有学反应才能分解分子本身，就像水如何用电分解成氢和氧一样。