60秒科学:Carbonation Has a Taste

Carbonation Has a Taste
In a study in the journal Science, researchers found that the taste buds for sensing sour also respond to carbonated beverages¹, because the fizz gets turned into chemical components², one of which is protons--basically simple, sour acid. Karen Hopkin reports

If you’ve ever craved³ an ice-cold soda⁴, you know that sometimes you’re just looking for something that tastes…fizzy. If that sounds odd, scientists have discovered that carbonation actually has a flavor. And that our taste buds can sense CO2.

Bubbly soft drinks tickle⁵ our tongues with their effervescence. But researchers got to wondering whether we can taste the carbonation. To find out, they studied mice whose taste cells had been turned off, one flavor at a time. So, one mouse couldn’t taste sweet things, another couldn’t taste bitter, a third couldn’t taste salt, and so on. And they found that mice lacking the cells that sense the taste sour no longer respond to CO2.

Probing further, they discovered that eliminating a single gene⁶ renders these mice blind, if you will, to the taste of carbonation. That gene encodes an enzyme⁷ that breaks down CO2—and water…don’t forget the water—into bicarbonate and protons. And it’s the protons—which are essentially⁸ acid—that the sour-sensitive cells seem to sense. The work appears in the journal Science.

The scientists speculate that our CO2 sensor⁹ evolved to help us avoid food that’s spoiled. Yet we still like some of our drinks to include the delightfully¹⁰ acidic tingle¹¹ of a touch of CO2.

—Karen Hopkin
 

1 beverages   

n.饮料( beverage的名词复数 )

参考例句：

• laws governing the sale of alcoholic beverages 控制酒类销售的法规
• regulations governing the sale of alcoholic beverages 含酒精饮料的销售管理条例

2 components   

（机器、设备等的）构成要素，零件，成分； 成分( component的名词复数 )； [物理化学]组分； [数学]分量； （混合物的）组成部分

参考例句：

• the components of a machine 机器部件
• Our chemistry teacher often reduces a compound to its components in lab. 在实验室中化学老师常把化合物分解为各种成分。

3 craved   

渴望，热望( crave的过去式 )； 恳求，请求

参考例句：

• She has always craved excitement. 她总渴望刺激。
• A spicy, sharp-tasting radish was exactly what her stomach craved. 她正馋着想吃一个香甜可口的红萝卜呢。

4 soda   

n.苏打水；汽水

参考例句：

• She doesn't enjoy drinking chocolate soda.她不喜欢喝巧克力汽水。
• I will freshen your drink with more soda and ice cubes.我给你的饮料重加一些苏打水和冰块。

5 tickle   

v.搔痒，胳肢；使高兴；发痒；n.搔痒，发痒

参考例句：

• Wilson was feeling restless. There was a tickle in his throat.威尔逊只觉得心神不定。嗓子眼里有些发痒。
• I am tickle pink at the news.听到这消息我高兴得要命。

6 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

7 enzyme   

n.酵素，酶

参考例句：

• Above a certain temperature,the enzyme molecule will become unfolded.超过一定温度，酶分子将会展开。
• An enzyme that dissolves the fibrin of blood clots.能溶解血凝块中的纤维的酶。

8 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。

9 sensor   

n.传感器，探测设备，感觉器（官）

参考例句：

• The temperature sensor is enclosed in a protective well.温度传感器密封在保护套管中。
• He plugged the sensor into a outlet.他把传感器插进电源插座。

10 delightfully   

大喜，欣然

参考例句：

• The room is delightfully appointed. 这房子的设备令人舒适愉快。 来自《现代汉英综合大词典》
• The evening is delightfully cool. 晚间凉爽宜人。 来自《现代汉英综合大词典》

11 tingle   

vi.感到刺痛，感到激动；n.刺痛，激动

参考例句：

• The music made my blood tingle.那音乐使我热血沸腾。
• The cold caused a tingle in my fingers.严寒使我的手指有刺痛感。