Tobacco contains an alkaloid called nicotine.

烟草含有一种叫做尼丁的生物碱。

This is the chemical formula for what alkaloid?

这是什么生物碱的化学式？

The bitter alkaloid that has this formula is caffeine.

这种苦味生物碱的配方是咖啡因。

It was but for a moment, for the action of the alkaloid is rapid.

可是这一切只是一会儿功夫，因为那种生物硷的用发挥得很快。

Alkaloids have many functions and effects, but almost all a bitter in taste.

生物碱有许多功用，但几乎所有的苦味。

That's an alkaloid—so it's in the same class of molecules as caffeine and nicotine.

那是一种生物碱——与咖啡因尼丁属于同一类分子。

Now, from a chemical perspective, caffeine can be described as both a methylxanthine and an alkaloid.

从化学角度来看，咖啡因既可述为甲基黄嘌呤，也可述为生物碱。

A group of drugs known as the vinca alkaloids, commonly included in chemotherapy regimens, are derived from Madagascar periwinkle.

常在化疗方案中看到的一种称为长春花生物碱的药物，是从马达加斯加的长春花中提取的。

The hopper's diet shifts to include plants with toxic alkaloids.

跳跃者的饮食转变为包括含有有毒生物碱的植物。

It's a mild natural stimulant, a type of alkaloid.

它是一种温的天然兴奋剂，一种生物碱。

Think of the molecular target of a neurotoxic alkaloid as a lock, and the alkaloid itself as the key.

将神经毒性生物碱的分子靶标想象成一把锁，将生物碱本身想象成钥匙。

While alkaloids as a whole are a broader group of naturally occurring organic compounds, defined by having at least one nitrogen atom.

而生物碱为一个整体是一个更广泛的自然存在的有机化合物组，定义为至少有一个氮原子。

The plants produce this alkaloid in order to protect them against insects and from other plants growing too close to them.

植物产生这种生物碱是为了保护它们免受昆虫其他生长在它们附近的植物的侵害。

Despite all the sweet tasting things that we tend to put into caffeinated beverages caffeine itself is a bitter, white, powdery alkaloid.

尽管我们倾向于在含咖啡因的饮料中加入所有甜味的东西，但咖啡因本身是一种苦的、白色的粉状生物碱。

On top of this, alkaloids from the vine have been shown to induce apoptosis in mice melanoma cells and certain liver cancer cells in humans.

除此之外，卡皮木藤条的生物碱已证实促进小鼠黑素瘤细胞人类的某些肝癌细胞凋亡。

These tiny animals defend themselves using hundreds of bitter-tasting compounds called alkaloids that they accumulate from consuming small arthropods like mites and ants.

这些微小的动物使用数百种称为生物碱的苦味化合物来保护自己，这些化合物是通过食用螨虫蚂蚁等小型节肢动物而积累的。

One of their most potent alkaloids is the chemical epibatidine, which binds to the same receptors in the brain as nicotine but is at least ten times stronger.

他们最有效的生物碱之一是化学 epibatidine，它与大脑中与尼丁相同的受体结合，但至少强十倍。

It's native to India and Southeast Asia, and its bark contains a poison called brucine, but the real lethality comes from the trees round green-to-orange fruit which contains the alkaloid strychnine.

马钱子原产印度与东南亚，它的树皮富含称为 Brucine 的有毒生物碱。但真正会死人的部分是马钱子-圆圆的，绿色到橙色的果实含有有毒生物碱：马钱子碱。

Like caffeine, theobromine is a type of alkaloid, which is a huge class of molecules that generally contain rings with at least one nitrogen atom in them, and alkaloids often have physiological effects on humans and other animals.

咖啡因一样，可可碱属于生物碱的一种，生物碱是相当大的一类分子，一般来说它的环中会包含至少一个氮原子，生物碱通常会使人类及其他动物产生生理用。

It's hard to know exactly why we evolved to be better at digesting theobromine, but it might be because alkaloids mostly come from plants, and our ancestors ate a lot more plants than early cats or dogs did.

我们很难确切了解为什么我们的身体会进化成较容易消化可可碱，有可是因为生物碱大部分都来自植物，而我们的祖先吃的植物比前的猫狗所吃的植物多很多。