中級 美國腔 102422 分類 收藏
With its stimulating effects, it's easy to understand why coffee is the second most traded commodity on Earth after oil.
For many, it keeps us awake and moving through our busy days.
But how does it work? What exactly does coffee do to your brain?
Whenever you're awake, a chemical called adenosine slowly accumulates in your brain.
And this adenosine binds to receptors which slow down brain activity.
Ultimately, the more adenosine there is, the more tired your brain feels.
Which makes sense, as the longer you're awake, the more fatigued you become.
Conversely, while you sleep, the concentration of adenosine declines, gradually promoting wakefulness.
But it turns out that the caffeine in your coffee is incredibly similar to adenosine in structure.
The caffeine works its way through your bloodstream and into your brain,
where it starts to compete and bind with adenosine receptors.
But because it is not adenosine, the sleepiness effect isn't felt.
Adenosine can no longer bind, meaning it's calming properties are diminished,
which is great for you when you're feeling tired!
However, with long term use of caffeine, your brain responds by creating more adenosine receptors,
which means more caffeine is required to elicit the same response.
It also means that when you try to quit drinking coffee or miss your daily intake,
you might experience some withdrawal symptoms and feel more tired than you would have before you ever drank coffee!
But the caffeine doesn't stop there!
It also stimulates the production of adrenaline.
You know, the Fight or Flight hormone.
This increases your heart rate, gets your blood pumping, and even opens up your airways.
Furthermore, it affects Dopamine levels by preventing its reabsorption in the brain, which makes you feel happy!
In fact, this is the exact same thing that cocaine does, just to a lesser degree.
It's a drug, after all!
This dopamine stimulation is also the aspect of coffee that makes it moderately addictive.
So can you drink too much coffee?
It turns out there is a lethal dose of caffeine which is somewhere around 150mg of caffeine per kilogram of our body.
This means if you weigh 70kg, you would require 14,000mg of caffeine to overdose.
Put into perspective, an average cup of coffee contains roughly 150mg of caffeine, meaning if you are 70kg, approximately 70 cups of coffee would kill you.
However, you'd have to drink those cups all at once making it effectively impossible to overdose on caffeine from coffee,
since you wouldn't be able to physically fit that much in your stomach.
You'd also start experiencing mania and hallucinations before getting to this point.
Caffeine also has a half life of around 6 hours.
So if you drank a standard coffee with around 150mg of caffeine,
after about 6 hours there will only be 75mg left in your system and you'll be feeling half of the effect.
And 6 hours after that, you'll have 37.5mg, leaving more room for adenosine to jump back into action.
Which is why you may reach for another cup throughout the day,
to maintain that glorious, alert and energetic feeling.
So drink up! And enjoy the buzz while it lasts!
And for all of you in school, while we know caffeine is key, so are good deals on textbooks!
So we've teamed up with SlugBooks.com to get you the cheapest prices for the books you need.
All you have to do is head to SlugBook.com/AsapSCIENCE and search the ISBN number of the books you're looking for.
SlugBooks will then compare prices from all across the net. Seriously, we know how expensive textbooks can be, so hopefully this will save you some money!
Got a burning question you want it answered? Ask it in the comments or on Facebook and Twitter. And subscribe for more weekly science videos!



咖啡對你的大腦做了什麼事?Your Brain On Coffee!

102422 分類 收藏
朱朱 發佈於 2015 年 3 月 6 日    朱朱 翻譯    Gisele Sung 審核



quit+Ving / quit+to V1:07
quit 這個動詞的意思是「放棄、停止」,後面可以加上一個動作。quit 的用法和 stop 類似,若欲表達放棄做某事物,後面所接的動詞必須使用動名詞 (Ving) 的形式,例如戒煙為 quit smoking,戒酒為 quit drinking;若欲表達放棄前一件事物而去做另一件事物,後面所接的動詞則要用不定詞 (to V),例如辭職去創業為 quit to start my own career。另外,be quit of… 可以表示「擺脫 / 脫離某人事物」。


remember+Ving: 記得做過某件事(已經做過)
remember+to V: 記得去做某件事(事情還沒做)
E.g., I remember talking to you before.
E.g, Please remember to hand in the application.

forget+Ving: 忘記做過某件事(已經做過)
forget+to V: 忘記做某件事(事情還沒做)
E.g., Oh, I can’t have a night snack. I forgot brushing my teeth.
E.g., Sorry, Tim. I forgot to bring your jacket.



withdrawal symptom1:10
就字面來看,withdrawal 的意思為「撤回」,symptom 的意思為「症狀」,而兩者組成在一起的  withdrawal symptom 則是指在戒酒或戒毒時常發生的「戒斷現象」,由於身體對某些物質產生依賴,因此在戒除時身體會陸續產生一些不適的狀況,例如焦躁不安 (anxious)疲倦 (exhausted)暈眩 (dizzy)失眠 (insomnia) 等等。


tipsy 微醺
get (be) drunk 喝醉了
wasted/ plastered 醉醺醺的
blind drunk 酩酊大醉
drunken brawl 酒後鬧事
hangover 宿醉
sober up 酒醒了

其實 flight 較常見的意思為「飛機的班次」,例如 215航班可以用 Flight 215 來表示,若希望朋友搭飛機時一路順風,可以祝他 have a safe flight

passport 護照
service charge 手續費
terminal 航廈
baggage/ luggage 行李
hand-carry bag 隨身行李
shuttle bus 機場巴士
captain 機長
flight attendant 空服員
time different 時差
jet lag 時差症候群

* 同場加映

超可愛!美國維珍航空飛航安全教學影片 (Virgin America Safety Video)

enjoy the buzz2:45
buzz 原本的意思是噪音或信號聲,但可以延伸為「讓人感到有趣興奮的事物」,因此 enjoy the buzz 指的是「享受這樣快感吧!」其實 buzz 也可以是「八卦」的意思,當下次想問別人八卦時,可是試著用 buzz 這個單字喔!另外,buzzword 代表「流行字彙」,像是台灣很紅的 ptt 鄉民用語等等都可以稱為 buzzword

E.g., That’s nothing compared to the buzz I get from alcohol.
E.g., Tell me what’s the buzz about Mia’s new boyfriend?

不知道大家覺得最近的 buzzword 是什麼呢?




  1. 1. 單字查詢


  2. 2. 單句重複播放


  3. 3. 使用快速鍵


  4. 4. 關閉語言字幕


  5. 5. 內嵌播放器


  6. 6. 展開播放器


  1. 英文聽力測驗


  1. 點擊展開筆記本讓你看的更舒服

  1. UrbanDictionary 俚語字典整合查詢。一般字典查詢不到你滿意的解譯,不妨使用「俚語字典」,或許會讓你有滿意的答案喔