Placeholder Image

字幕列表 影片播放

  • I used to drink a lot of coffee on my hand, shook even more than they do now.

  • About 12 years ago, maybe more now.

  • I went to China for a week, and when I left I was really addicted to coffee.

  • And when I came back, I was found myself addicted to green tea.

  • And since then I've drunk nearly entirely green tea, and very rarely do I drink coffee.

  • And the result is that if I do have some coffee, I feel hyper for the rest of the day and I really can't sleep well.

  • It's a molecule I know.

  • On DDE, I can just about recognized its structure together.

  • Some carbons, carbons got nitrogen, oxygen, hydrogen, scattering atoms everywhere.

  • If I just saw it is a random molecule, I would probably recognize it because you usually see it on people's coffee cups and things like that.

  • So there's quite a good him.

  • This is capping.

  • If you've never had coffee before, then people do get some stimulation from it.

  • There's no doubt about that's been proven.

  • It can help making a bit more alert and feel bit more vital for a for a few minutes.

  • If you have too much.

  • Of course, lethal dose of coffee is about 80 cups a day, so do not approach that at all.

  • I have read the theory, and I don't know if this is correct that if you take coffee or and some other caffeinated drink, it's a regular time each day.

  • Then your body starts making the antidote to the caffeine before you get the coffee time.

  • So if you have coffee at 10 30 in the morning round about 10 o'clock, your body starts making this antidote.

  • So you've tend to feel really quite in need of the caffeine just to get you back to normal state.

  • So this is about six cups of coffee in here.

  • We're just gonna cool that dying.

  • But on the other hand, if you're suddenly given coffee at a time when you're not expecting it, then your body hasn't gots ready to receive this dose of caffeine, and it has a much bigger effect than you expect.

  • And so it may be not so much that people are addicted to coffee, but they are counteracting the negative effects of what's in their body.

  • Caffeine is very soluble in hot.

  • There's much, much less, 30 times less soluble temperature, Walter.

  • So we're gonna cool it down.

  • So it's like soluble in water.

  • Thank you.

  • Drinking tea and coffee is very important in science in the UK and in many labs, people meet together every day to drink tea and coffee.

  • And some of the best ideas can grew up over tea and coffee.

  • Because when people are relaxed, suddenly clever ideas come in their head.

  • An unexpected side effect of caffeine is its role in science, not directly, but in many labs.

  • Many departments like this one that noting him.

  • The scientists meet together once or perhaps twice a day to drink coffee.

  • I'm quite often they have really good ideas, the caffeine's or relax system on when they're not thinking really hard.

  • Suddenly, a good idea comes into their head.

  • In fact, at the Laboratory of Molecular Biology in Cambridge, which is one I think 14 Nobel Prizes there was a rule.

  • Perhaps there still is that if people are discussing in the coffee room, it's not allowed to close in case there just about to get a good idea.

  • And if the coffee room closes, it may be lost forever, so you never know.

  • If you sit a long time drinking coffee, you might win the Nobel Prize.

  • Water water's more dense than Ethan State, so it sinks to the bottom.

  • They're not admissible.

  • Restraining off that button black male with water because it goes down, you're seeing the top layer is actually fairly clear.

  • So the caffeine now hopefully is in that top, right?

  • Um, this this really boom, boom, boom, But flask, there's still some water in the last eight.

  • So we're gonna use is a drying agent.

  • Magnesium sulfate have always known is Epsom salts.

  • Students often ask me, How do you know how much magnesium sulphate It's a drawing.

  • The answer is when it goes white and fluffy.

  • So it's quite a lot of water, in a sense, Claridges and clump together.

  • So it's probably more when you get that sort of snow storm effect.

  • Just let that dry for a moment.

  • Filter off.

  • This is so what we have here is our caffeine.

  • So the reds here do no oxygen.

  • You've got carbon atoms represented by the black.

  • These smaller white ones are hard shin.

  • And then the blue ones here, which you've got four or nitrogen, so it's kind of the most common elements that make up so many aromatics.

  • Organic molecules.

  • I tried to find a a mug with a caffeine molecule and had to go back to the parent table, but what we had sent in boy, one of our viewers.

  • Um, this gentleman here is clearly a fan off period videos, and he's there enjoying a video of Martin with his broom in hand.

  • But he also including his E mail to US tattoo that he's got, as you can see, that molecule of coffee.

  • So it's clearly a much more devoted fan to the molecule than I am.

  • I just prefer drinking it rather than thinking on myself.

  • It's an hour.

  • Caffeine's in the last eight solution on.

  • We're not gonna remove the last type from it.

  • So you put one of these only is called check clips.

  • Dr.

  • Keck sadly died last year, but very handy clip that bears his name will go on for many, many years to come.

  • No need to card ice cases, cowboy approach time, Dick.

  • Hey, we got some solid safe to use that to condense the last eight so it doesn't go down the drains or into the atmosphere.

  • Okay, so what we're doing is we're lowering the pressure in the system, so that means that alone's boiling point.

  • We're loing boiling point wreath.

  • Alas, it tight.

  • So in here, we've got the last type very low pressure in here.

  • Currently around 90 million bars on that solvent is evaporating.

  • It's coming up here, and it's condensing on this very cold, hard, ice cold finger.

  • Here you can see it coming down and being collected in the flask below.

  • So what we want is to remove all of that solvent.

  • Just leave what was in Seoul.

  • I hope we'll have something that I don't think it's going very much because it was only six cups coffee, but there should be 20 or 30 milligrams, maybe a little bit more for lucky.

  • So what do you think about someone doing themselves with a caffeine molecule?

  • It's certainly a level of geekdom that I have not subscribe to, but I commend him for his devotion to this particular molecule.

  • Well, that's about to change because we've been sent something which I'm giving you is a gift.

  • This this was sent to periodic video really well.

  • They seize.

  • Absolutely incredible.

  • Oh, my gosh.

  • So we've got rid of most of the eighth.

  • Last tight.

  • Now, just last few dregs coming off.

  • You see that?

  • We've got a fairly light yellow Parajuli.

  • Some of the colors come through from the coffee.

  • So there we go caffeine.

  • Now, if we were really good chemist, we re crystallized like it's a nice white crystals on.

  • What we're gonna do is just gonna put this on a high vacuum system to get the very last traces of ether last.

  • This is absolutely gorgeous.

  • I've got a caffeine molecule on a chain.

  • It's a necklace, evidently, but its so called what is this owner was made off.

  • I absolutely adore.

  • This is it's incredible.

  • And it's so caress its allies.

  • Caffeine.

  • It's so sweet.

  • It's so cute.

  • And I love it.

  • But you just you just send people who adorn themselves with Cap.

  • Yeah, I know.

  • I take it back now than I look like a complete idiot at today.

  • There's a difference between getting inked permanently and being able to take it on and off.

  • I'm gonna wear this because I I'm going to the Webby Awards.

  • Um and I'm gonna wear this.

  • I'm definitely gonna wear this on the night.

  • It's gonna be amazing.

  • I had planned on wearing something else, but no, I'm definitely gonna take this to New York.

  • And I'm gonna wear it for the Webby Awards because it's just it's absolutely immense.

  • Love it.

  • Thank you to whoever made this.

  • That's been on the five minutes.

  • So take this off now what?

  • 0 100 milligram.

  • So six cups of coffee has 100 milligrams of caffeine 17 or so milligrams in a cup of that particular company.

  • So it's amorphous powder form.

  • Thank you very much.

I used to drink a lot of coffee on my hand, shook even more than they do now.

字幕與單字

單字即點即查 點擊單字可以查詢單字解釋

B1 中級

咖啡中的咖啡因含量有多少? (How much caffeine in coffee?)

  • 22 0
    林宜悉 發佈於 2021 年 01 月 14 日
影片單字