Carbon... SO SIMPLE: Crash Course Biology #1 

My new flirting line: “Hey girl, you are just the prettiest collection of organic compounds rambling around in a sack a water”.

"Even the sexiest person you have ever met in your life is just a collection of organic compounds rambling around in a sack of water." I don't know about you, but thinking about that statement gives me tremendously less anxiety when conversing with people I find attractive

When a high RU-vidr explains biology better in 12 minutes than sober qualified teacher does in 12 weeks.

I like how everyone says that Hank is drunk or high when I know for a fact this man is completely sober he just is That Way

Why do they even HAVE school anymore? Just make us watch Crash Course. It's so good. I actually learn and it's fun and not fucking stressful as shit.

No one: Hank: *WHY CARBON IS A TRAMP*

This Corona Crisis is finally giving me time to binge watch CC vids

I'm here from the year 2019 and Hank Green has facial hair.

John green taught me books can make me even more depressed than I thought and Hank Green made me realize biology is cool which inevitably made me realize I want to be a forensic scientist. Thank you Hank

My AP Bio teacher took an ENTIRE week to teach us this... and you (a drunk man) taught it to me in 12 minutes!! Amazing

"Hi! I'm Hank. I'm assuming you're here to learn about biology" The guy is physic.

“And like people getting on a bus, they prefer not sitting next to each other”. 🤣🤣

Great way to get ahead so I can make it into honors bio. Crash course is absolutely fantastic. It's essentially free school. And better school too! It's gets to the point and isn't all information. Its fun, quick, and educational. You've done something amazing here, Hank!

back when hank was jus bit more edgy

I remember my 6th grade teacher playing this and ..... it was ended pretty early on

bio final tomorrow, let the marathon begin

As someone who is taking AP Bio, never studies, and has a major test in a few weeks, this series saves lives

I just learned 8 things in 12 minutes that would take me 8 weeks to learn in school...

Bold of you to assume I want to live

I'm not used to him talking so slow!

its crazy how much hank has evolved and grown to be more fluent and confident

"I am a collection of organic molecules called Hank Green" I fricken lost it XD

I just wanted to thank y'all at Crash Course for this biology series!! Last year I had to take a state biology test that is a part of a series of tests that are mandatory to pass to get your high school diploma. I decided to watch these biology vids to help prep because I wasn't feeling prepared enough. It ended up that a big section of the test was on a topic we didn't go over in class but I had watched Crash Course vids about it. Anyway I just recently found out that I did pass my test!!!! So just thank you guys so much!! I don't know if I would've made it through my test if it wasn't for these vids!!!😃😃👏🏻👏🏻👏🏻👏🏻

My new definig motto: "I don't want to destroy. i just want to be delicious."

He sounds a little drunk. Which is the best way to teach.

My intro to biology teacher is near retirement, makes learning the subject a drag, makes us do online homework so she doesn't have to do the work and I thought I wouldn't get the A I was hoping for.. Except I stumbled upon this channel, thank God for the internet.

Hank: "I assume you are a human being." Me: WOOF WOOF

I love the way you teach. I have ADHD and can never pay attention so thanks for being weird and not boring like most professors . With my ADHD , it affects me remembering things. I want to actually know and learn this subject and other subjects and not just memorize for the test then forget everything a month later. Any advice on studying or other tips to really keep the info embedded in my mind??

Hank Green, explaining in 12 minutes what NONE of my Chemistry or Biology teachers were able to explain.

Hey there Crash Course. I'd just like to say that all of these videos you guys produce are unbelievable and completely amazing. They help me so much in school, I'm a grade 10 student in South Africa by the way, and subjects that I sadly wasn't able to take during school like history I can still keep up with here, and things like psychology that aren't treated as an official subject during school but that are so interesting are also available to people like me! Thank you to the whole Crash Course team!

Hank: you can even use the number keys on your keyboard to move around in the video Me: what? since when can you do tha- OH MY FREAKING GOODNESS IT WORKS!

"Being that you are, i assume, a human being"Now that's how you strart a class

PLEASE create a Crash Course geometry cause i'm bad at math and this is the only way i learn without being confused

Poor Gilbert Lewis. He deserved so much more. :(

I just catched up with the whole year of 9th grade and I have never understood chemistry this good. Thank you!

“even the sexiest person you’ve met in your life is just a collection of organic compounds ramblin around in a sack of water” lol thanks hank i’m going through a breakup rn and that actually made me feel better😤👏🙌

If you're binge watching because the AP bio exam is Monday and you know it clap your hands 👏🏻👏🏻👏🏻👏🏻👏🏻

Oooh yeah, I love Hank in his stoner phase

Hank from 8 years ago is so different from Hank today, but just as wonderful.

AP Test tomorrow, re watching every single bio Crash Course video on repeat till I get a 5

Apparently everyone here is studying for tests while I'm just sitting here, enjoying my daily Hank, instead of doing actual school work.

Thank you for suming up half of a semesters worth of intro to chemistry in about 12 and a half minutes, if only more college classes could be like you.

I'm watching the video after 10 years. It's really amazing that since I was 5 years old there are people who care and share this great information.💜

Great Video. When I was doing biology at school, I used to see it as a subject which just has to be crammed by heart. After all these years and completing my medical school, I now know the importance of understanding concepts.

wow. u look totally different with Beard

Genuinely sat here at the begining like... That looks like Hank Green.. That's not Hank... But it kinda looks like him, with more hair... Maybe he just happens to look like a hairy version of Hank. "HI, IM Hank"

I thought it was very important to write down what he said "Like any good 50 cent song, biology is just about sex not dying". My brain is already getting bigger because of that information!

Hank Green is one of the funniest people I have found on crash course, but at the same time, he is very good at explaining. Thank you so much!

Who else is here cramming for the AP Bio Exam on Monday?

who else is just watching a bunch of crash course videos to pass finals?

THANK YOU SO MUCH, CRASH COURSES AND HANK! You guys have made me love learning so much more and I listen frequently and with great interest to these videos. Bless you! The ending was also great lol

I have a fantastic Bio teacher at Uni (really passionate about the subject), but this channel has been insanely helpful when it comes to the animated visuals. I can't thank you enough.

i put the speed to 1.25, it sounds exactly like normal hank

Who's cramming for the AP test right now?

Time to binge this entire biology playlist so I can maybe pass my exam tomorrow

I homeschooled now, and before. My teacher wouldn't even teach us this, this will be great for the future! Thanks Hank, also, THIS IS BETTER THEN ANY OTHER SCHOOL!

Holy shit! Hank has a beard and moustache in this video! A feat that even John Green cant do! I mean wow... I mean thats a good beard. I mean.. uhmm he must keep it. No homo.

"Biology is just about sex, and not dying" LOL

in ap bio rn and this video is more helpful than 6 weeks of my teacher rambling 😭😭😭

crash course i just wanted to say thank you for everything and getting me through life

i like this teacher, he looks like he hasn't had the idealism beaten out of him yet.

Am I the only one who watches these for fun?

I saw the skeletal system one in school and then immediately jumped over to the whole playlist because this is so fun to watch and you also learn something! When i have a biology test this is the thing i'm immediately jumping to. Congrats CrashCourse, you've earned a subscriber. :)

Thank you soooo much for your videos!!! I’m going from AD Army to full time student (med school!!) in 2019!! I need to refresh my memory on all things chemistry, biology, physics, etc...!! Each video is helping me rebuild my confidence in my decision to go back to school and pursue medical school:)

Im not sure if you guys read your comments but its finals week and i wanted to thank both of you for helping me with both my worlds religions class and biology class. both of you have that charisma to make your viewers want to pay attention. you both have a skill to make these topics that would (to most) be very boring to learn and made them very exciting as they should be. thank you so much for doing what you do. you have helped me pass all my tests :) and made learning these very complicated subjects very easy. thank you so much

He looks fucking great with a beard and mustache.

I came from future Year: 2023 There is holy different Hank there

You've come a long way, my friend. I just found this channel, and I've been watching the latest videos. This was 10 years ago; fantastic improvement in all aspects!

I'm :) so :) confused :) why :) did :) I :) ever :) pick :) biology :) as :) a :) subject :) wtf :) is :) an :) atom :)

If I had Hank Green as a teacher I might actually learn something

I definitely recommend this episode if you are going into chemistry! Also thank you so much for making free educational content for us 😀

Hank is like sleepy and tired but I love the video.

Wow Crashcourse team. You've taught me more in one episode of Crashcorse that a months worth of Science classes provided by my school. This just proves how amazing you guys are and how crappy this education system is.

Holy shit, Lewis is Leonardo DiCaprio.

Today's a big day for me. Seeing as I no longer formally study biology, I can finally watch these for pleasure rather than to study for a test. Yay learning!

"Good lord, i'm in a chair" - still gets me in 2017

Ah, Hank with a beard and mustache XD

I really appreciate this page. Sometimes reading information from a textbook just isn't enouph for students to really grasp the concept they're being taught. The visuals work great in these videos.

Thank you for making these! I have a BA but going back to school for nursing and never took college biology... And haven’t been in school in 10 years. I love all of crash course!

Hank: you can just type number on your keyboard to go back. Me: No, sorry Hank, this is 2024. I’m watching this on my phone.

Just passed my Natural Sciences CLEP examination - and it's 100% because of crash course! Thanks for saving me a ton of money from having to take a class... and making me more interested/informed about important science!

currently binge watching all of this as my Biology exam is tomorrow oops

Hank: Good lord, I'm in a chair Me: @_@

>be me >finals coming up without a textbook to study with >Look up biology 101 and find this >put on 1.25 and 1.50 speed >profit

Oh my gosh; watching this Low-Key Hank after finishing Crash Course Chemistry is pleasantly weird.

You're awesome. Thank you for making biology more accessible

These playlists are incredible. I'm currently going for a PGCE teaching course and they're perfect for catching up on the national curriculum :D

you literally saved me from a suuuuuuper long afternoon of revising for my medicine exam tomorrow, wish me good luck! keep on going, I really hope that youtube can become more of an educational place available for everyone!

I'm on winter break from college, but I'm a science major. And I'm watching these videos to keep my brain awake for next semester :3

If you’re wondering this is how the most revolutionary course in biology of all time begins. Come today to learn about covalent and ionic and hydrogen bonds. What about electron orbitals and the octet rule and what does it all have to do with a mad man named Gilbert Lewis? It’s contained within. Hello. I’m Hank. I assume you’re here because you’re interested in biology. And, if you are, that make sense because, like any good 50 Cent song, biology is just about sex and not dying. Everyone watching this should be interested in sex and not dying, being that you are, I assume, a human being. I’m going to be teaching this biology course differently than most courses you’ve ever taken in your life. For example, I’m not going to spend the first class talking about how I’m going to spend the rest of the class. I’m just going to start teaching you like right about now. I might say one more thing before I start teaching. Yes, I am going to. It’s that, if I’m going too fast for you, great thing about RU-vid is that you can just rewind, watch stuff over and over again if it’s confusing and hopefully it will become less confusing and you’re even allowed to fast forward through the bits that you already know. Another tip, you can actually even use the number keys on your keyboard to move around in the video. And I promise, you can do this to me as much as you want and I am totally not going to mind. A great professor of mine once told me that in order to really understand any topic, you have to understand a little bit of the level of complexity just below that topic. The level of complexity just below biology is chemistry, unless you’re a biochemist in which case you argue that it’s biochemistry. Either way, we’re going to have to know a little bit of chemistry in order to get through biology. And so that, my friends, is where we’re going to start. I am a collection of organic molecules called “haint green.” Organic compounds are a class of compounds that contain carbon and carbon is this sexy little minx on the periodic table that’s disinterested in monogamy…Jezebeel, tramp, hussy. When I say carbon is small I mean that it’s actually, as an atom, it’s a relatively small atom. It has six protons and six neutrons for a total atomic weight of 12. Because of that, carbon doesn’t take up a lot of space. And so carbon can form itself into weird rings and sheets and spirals and double and even triple bonds. It can do all sorts of things that could never be accomplished by more bulky atoms…basically your atomic equivalent of an Olympic gymnast. It can only do all of those wonderful, beautiful, elegant things because it’s kind of tiny. I also said that carbon is “kind” and that’s an interesting sort of thing to say about an atom. It’s not like some other elements that are just desperately trying to do anything they can to fill up their electron orbitals. No, carbon knows what it’s like to be alone and so it’s not all “Please!! I’ll do anything for your electrons” needy like fluorine or chlorine or sodium is. Elements like chlorine, if you breath them in they like literally tear up your insides. And sodium…sodium is insane. If you like put it in water, it explodes. Carbon, though, it wants more electrons, but it’s not going to kill to get them. It makes and breaks bonds like a 13-year-old mall rat and it doesn’t even hold a grudge. Carbon is also, as I mentioned before, a bit of a tramp because it needs four extra electrons and so it will bond with pretty much whoever happens to be near by. And also, because it needs four electrons, it will bond with two or three or even four of those things at the same time. And carbon is willing and interested to bond with lots of different molecules like hydrogen, oxygen, phosphorus, nitrogen or to other molecules of carbon. It can do this in infinite configurations allowing it to be the core atom of complicated structures that make living things like ourselves. Because carbon is this perfect mix of small, kind, and a little bit trampy, life is entirely based on this element. Carbon is the foundation of biology. It’s so fundamental that scientists have a pretty difficult time even conceiving of life that isn’t based on carbon. Life is only possible on earth because carbon is always floating around in our atmosphere in the form of carbon dioxide. So it’s important to know when I talk about carbon bonding with other elements, I’m not actually talking about sex. It’s just a useful analogy. Carbon, on its own, is an atom with 6 protons, 6 neutrons, and 6 electrons. Atoms have electron shells and they need to have these shells filled in order to be happy fulfilled atoms. So carbon has 6 total electrons…2 for the first shell, so it’s totally happy and 4 of the 8 it needs to fill the second shell. Carbon forms a type of bond that we call covalent. This is when atoms actually are sharing electrons with each other. So in the case of methane, which is pretty much the simplest carbon compound ever. Carbon is sharing its four electrons in its outer electron shell with four atoms of hydrogen. Hydrogen atoms only have one electron. So they want their first S-orbital filled. Carbon shares it’s four electrons with those four hydrogens and those four hydrogens each share one electron with carbon. So everybody is happy. In chemistry and biology, this is often represented by what we call Lewis dot structures. Gilbert Lewis, the guy who thought up Lewis dot structures, was also the guy behind Lewis acids and bases. He was nominated for the Nobel Prize 35 times. This is more nominations that anyone else ever in history. And the number of times he won is roughly the same number of times that everyone else in the world has won…which is zero. Lewis disliked this a great deal. It’s kind of alike a baseball player having more hits than any other player in history and no homeruns. He may have been the most influential chemist of all times. He coined the term “photon,” he revolutionized how we think about acids and bases and he produced the first molecule of heavy water. He was the first person to conceptualize the covalent bond that we’re talking about right now. Gilbert Lewis died alone in his laboratory while working on cyanide compounds after having had lunch with a younger, more charismatic colleague who had won the Nobel Prize and who had worked on the Manhattan Project. Many suspect that he killed himself with the cyanide compounds that he was working on, but the medical examiner said “heart attack” without really looking into it. I told you all of that because the little Lewis dot structure that we use to represent how atoms bond to each other is something that was created by a troubled mad genius. It’s not some abstract scientific thing that’s always existed. It’s a tool that was thought up by a guy and it was so useful that we’ve been using it ever since. In biology, most compounds can be displayed in Lewis dot structure form and here’s how that works. These structures basically show how atoms bond together to make up molecules. And one of the rules of thumb when making these diagrams is that the elements that we’re working with here react with one another in such a way that each atom ends up with 8 electrons in its outermost shell. That is called the Octet Rule because atoms want to complete their octets of electrons to be happy and satisfied. Oxygen has 6 electron in its octet and needs 2, which is why we get H2O. It can also bond with carbon, which needs 4, so you get two double bonds to two different oxygen atoms and you end up with CO2 (that pesky global warming and also the stuff that makes all life on earth possible). Nitrogen has five electrons in its outer shell. Here’s how we count them. There are four place holders. Each of them wants two atoms. And like people getting on a bus, they prefer to start out not sitting next to each other. I’m not kidding about this. They really don’t double up until they have to. So, for maximum happiness, nitrogen bonds with three hydrogens forming ammonia or with two hydrogens sticking off another group of atoms which we call an amino group. And if that amino group is bonded to a carbon, that is bonded to a carboxylic acid group, then you have an amino acid. You’ve heard of those, right? Sometimes electrons are shared equally within a covalent bond like with O2. That’s called a non-polar covalent bond. But often, one of the participants is more greedy. In water, for example, the oxygen molecule sucks the electrons in and they spend more time with the oxygen than with the hydrogens. This creates a slight positive charge around the hydrogens and a slight negative charge around the oxygen. When something has a charge, we say that it’s polar. It has a positive and negative pole. And so it’s a polar covalent bond. Now let’s talk a moment about a completely different bond which is an ionic bond. That’s when, instead of sharing electrons, atoms just completely, whole-heartedly donate or accept an electron from another atom and then live happily as a charged atom. And there actually is no such thing as a charged atom. If an atom has a charge, it’s an ion. Atoms, in general, prefer to be neutral. But compared with having a full octet, it’s not that big of a deal. It’s just like we often choose between being emotionally balanced and sexually satisfied, atoms will sometimes make sacrifices for that octet. The most common ionic compound in our daily life is salt…sodium chloride (NaCl). This stuff, despite its deliciousness, as I mentioned previously is made up of two really nasty chemicals - sodium and chlorine. Chlorine is what we call a halogen which is an element that only needs one electron to fulfill its octet and sodium is an alkaline metal which means that it only has one electron in its octet. So chlorine and sodium are so close to being satisfied that they will happily destroy anything in their path in order to fulfill their octet. And thus, there’s actually no better outcome than just to get chlorine and sodium together and have them loving on each other. They immediately transfer their electrons so that sodium doesn’t have its one extra and chlorine fills its octet to become Na+ and Cl- and are so charged that they stick together and we call that stickiness an ionic bond. And just like if you have two really crazy friends, it might be good to get them together so that they’ll stop bothering you, the same thing works with sodium and chlorine. You get those two together and they’ll bother no one. And suddenly they don’t want to destroy, they just want to be delicious. Chemical changes like this are a big freaking deal. Remember, chlorine and sodium, just a second ago, were definitely killing you and now they’re tasty. Now we’re coming to the last bond that we’re going to discuss in our intro to chemistry here and that’s the hydrogen bond. Imagine that you remember water. I hope that you didn’t forget water. Since water is stuck together in a polar covalent bond, the hydrogen bit is positively charged and the oxygen bit is negatively charged. So when water molecules are moving around, we generally think of them as a perfect fluid but they actually stick together a little bit - hydrogen side to oxygen side. You can actually see this with your eyes if you fill up a glass of water too full it will bubble at the top. The water will stick together at the top. That’s the polar covalent bonds sticking the water molecules to each other so that they don’t flow right over the top of the glass. These relatively weak hydrogen bonds happen in all sorts of chemical compounds. They don’t just happen in water and they actually play an extremely important role in proteins which are the chemicals that pretty much make up our entire bodies. A final thing to note here is that bonds, even covalent bonds, ionic bonds even with their own class are often much different strengths and we, you know, tend to just write them with a little line but that line can represent a very very strong covalent bond or a relatively weak covalent bond. Sometimes ionic bonds are stronger than covalent bonds but that’s generally not the case. And the strength of covalent bonds varies wildly. How these bonds are made and broken is intensely important to life and to our lives. Making and breaking bonds is, in fact, the key to life itself. And, like also, the key to death for example if you were to ingest some sodium metal. Keep this in mind as we move forward through biology. Even the sexiest person you have ever met in your life is just a collection of organic compounds rambling around in a sack of water. Review time.

When we get to finally discover the means of time travel, first thing I'm gonna do is to give Gilbert Lewis a hug -- whether he likes it or not.

Man it's been 16 years since I backed out from school. Probably alot longer since actually being taught these methods. It took me about an hour of studying this but man I got i think I got this first lesson down packed. All thanks to this man. You probably saving my life here. Whatever that's worth 😳😅🤩

WAIT HOLD UP Chemistry is the level below biology? THATS Y I FELT LOST DURING MY BIOLOGY COURSE CUZ I TOOK BIO IN 9th GRADE AND IN 10th GRADE IM TAKING CHEMISTRY so should I like... Look at crash course chem first?

my first comment online...this is what ive been waiting for! your class is amazingly fun and informative...i am so hungry to learn more and will be following your courses avidly...my science tutor is also quite impressed with what im learning from you....please keep up the good work...you are needed.

I'm a college student and this man teaches me better than my professor. We just write notes everyday and there is no hype class discussions.

Starting medical school soon, still use your videos to prepare. DON'T EVER STOP DOING THESE!

It'd be great if there was a course on physics

OMG after a year of Chemistry, I came to this video and I was like is this another brother

I watched all of these for fun wayyy back in the day, but now I have a Biology CLEP test coming up, so here we go again. :)

Watching this video exactly 10 years later and it's incredible!! Thank you Crash Course