Hank was not mistaken. For all the people arguing about tonicity: Hypertonic = a lot of solute Hypotonic = not a lot of solute They are relative terms. A solution on its own isn't called hypertonic, it has to be hypertonic to some other solution. If the cell is hypertonic to its environment, then the environment is hypotonic to the cell, and the cell takes on water. If the cell is hypotonic to its environment, then the environment is hypertonic to the cell, and the cell loses water. Hope that helps.
+fayruz fikry Water with salt in it is also a solution, same as water. The salt water is trying to make the concentration of salt water similar on both sides, so it flows over to the bit that has less salt water (the outside) to make them the same. I think? Makes sense to me.
+mikaela sofea I think that makes sense,and evidently salt can be seen moving through the membrane. Which kinda begs the question,was it really osmosis? From what I know osmosis is only the movement of the solvent,not the solute. If it was indeed osmosis,I think only the water should move around,not the salt.
Don't know the answer to that question. All the websites and dictionaries I have found define osmosis roughly the same: a solvent moving across a semi-permeable membrane from an area of high concentration to low concentration (of the solvent). Maybe Hank himself will answer the question? I heard he answers them himself sometimes. Sorry I couldn't help :(
+fayruz fikry I was confused by this too. I think only the cellulose membrane must be permeable to salt, otherwise, the water from the glass would have rushed in and the cellulose membrane would have swollen with more water. That would have been osmosis. I think what we were watching was diffusion of salt from the hypertonic solution in the hypotonic solution to gain equilibrium.
I really want to win valedictorian just so in my speech I can say "I would like to dedicate all of my good grades Crash Course, without of which, I would have failed." And that would be my whole speech. No inspiring words, just Crash Course.
This guy is my favorite human being ever. He’s quirky, funny and smart. He is pure genius. I don’t understand a darn thing until he explains it to me. And he does it in a manner that I feel he’s talking directly to me. Thanks dude.
I was once asked in a Biology test what ATP stands for. My answer was Awesome Tooth Paste. I obviously didn't believe that, but that's what happens when you don't revise for your tests.
pahaha xDDDD once,a collegue of mine was asked to write down on the whiteboard Glucose (like the chemical formula) and he wrote down literary G L U C O S E.
I am returning to school after maaaaany yearssssss! You all have helped me so much with your videos. I am actually excited about science for the first time.
Same here! I think my brain lost the capacity to read but gained the property of watching helpful RU-vid videos ;) Let's hope the knowledge sticks the same way though..
Dear Crash Course Biology, I am a Science teacher in Ecuador South America. I use your videos to reinforce information at the end of every unit. I am glad your talking rate has decreased which was the only con for your wonderful channel. Now my kids understand you clearly and i love the fact you have a table of contents at the end of the video.
Honestly Pankaj, I so wish I could have this in PDF version. But what I've been doing is basically watching video with subtitles and keeping the window open while I take notes, pausing it whenever I need. I also take screen caps and then insert them as diagrams into my notes. I hope this helps!
You have the gift of teaching! I have been reading this stuff in my textbook and looking at the pictures and retaining nothing. This video makes perfect sense and I just want to thank you for it!!!!!
I have an EXTREME love/hate relationship with your work here. These videos are informative AND entertaining! I love your presentation and energy! How could anyone possibly hate what you do? Well, here's my issue: I cannot show these videos to my middle school students because of language and X-rated references. You have NO idea how hard it is to find exciting videos that so clearly illustrate these points, while visually engaging the audience. Any chance we desperate middle school teachers can persuade you to create a PG version of Crash Course?!
I mean, its has grown up references boo-hoo. They've more likely than not already been exposed. And what's more important, their education or some minor references? They have to grow up eventually
I found him so hard to follow last year when I was actually learning Bio/Chem, but now!!! Thank you!!! It is awesome to have all of it condensed and explained so well, that has refreshed my knowledge so quickly.
I LOVE this channel!!! Thank you thank you thank you!!!!!! My professor will explain this to me and I won't get it, but as soon as you played this video I felt like a newly birthed genius ready to tell everyone that doesn't care about my newly found personal discoveries in biology.
You don't need to know this for GCSE at all, only the basics. You only need this at A-Level. At GCSE you only need to understand the osmosis etc around the cell, nothing more specific. Edit: I meant the bit about the 'Fluid Mosaic' Structure and hydrophbic heads & Phospho lipids etc. didn't realise this was a GCSE-ey type video, I was looking for A-Level results. lol :D SO overall most of this video goes into too much detail which is necessary for GCSE Knowledge, but no harm ofc.
That Sodium-Potassium pump illustration was the best one I've seen in my 3+ years of Chemistry & Anatomy... It makes so much more sense now.... I think there was a literal lightbulb that went on above my head.
I speak Spanish, so it's so interesting when I'm in class and the professor asks me something and I have to translate terms in my brain. like Adenosine tri phosphate to adenosin tri fosfato, and sometimes I get it wrong or pronounced it like English hahaha. Awesome videossssssssss
Attention Hank messed up on this video! At 2:39 he gets hypertonic backwords. A hypotonic solution is one in which the concentration of solutes is greater inside the cell than outside of it, and a hypertonic solution is one where the concentration of solutes is greater outside the cell than inside it.
Confused. Did you mix up the hypotonic and hypertonic, or have I just been taught wrong? I thought the hypotonic cell was the one that swelled and exploded.
+JuanDVene Yes, i think that he got it mixed up, i also learned the opposite, the hypotonic cell is the one that swells and 'explodes' as the salt/ion concentration is higher in the cell, then the outside, so water rushes in to try and over come this. ad Hypertonic is when the salt/ion concentration is super high outside, so the water in the cell rushes out to dilute the solution and the cell is left shriveled.
You can use hyper/hypotonic to describe both solutions. The one inside (Cytoplasm) the cell and the one outside. A solution is hypertonic when the concentration is higher than in an other solution. (Hypotonic is the same but reversed) When the cytoplasm is hypotonic (lower concentration than outside) the cell swells, because the outside is hypertonic to the cytoplasm. It is only a question of ones viewpoint.
+JuanDVene For osmosis, we look at the concentration of water instead of the solute. That's why the direction is from hypotonic(more water) to hypertonic(less water).
+JuanDVene he clarified it in the video in writing. Cell is hypertonic, but the environment is hypotonic. I was taught from the environment's point of view, he is explaining it from the cell's point of view.
This video saved me! I have been forced to take biology online, and the descriptions in my online lesson were not enough for me to understand the subject. But I looked for a crash course on the subject and now i understand passive and active transport.
thank you sooo much hank green for this video it is very helpful and reviewed my whole entire very confusing biology unit to make it very easy in 11 minutes! yes!
I just wanted to say around the 4:00 time, you kept saying that hypertonic would be water rushing in and it would get so full it could explode. From my understanding (we just learned this a few weeks ago in biology) hypertonic is when there is lack of water within the cell and becomes shriveled; where as hypotonic is a cell that is extremely full and can burst due to the pressure of the water. Just letting you know and you might want to add a text in the video that maybe states the correct definitions. Thank you for all your amazing videos! I definitely utilize them for my studies. Much appreciated! 😊
Re-watching these earlier videos makes it apparent just how far you have come, Hank. And yet, they are still so very amazing and awesome. It does make me wish you were less fantastic as I selfishly would love to have a conversation with you, science nut to science nut, but alas, perhaps in another life, when we are both cats.
I'm in nursing school and I swear that you are the only reason I am passing. I can't learn from my teacher. If I get my LPN degree, I am gonna be thanking you forever. lol.
You rock! thanks for actually explaining Bio in a language i understand. My text book doesnt make any sense to me, the way everything is explained is not comprehensible. I need to actually understand what the information means, like truley understand. And you really have a great way of explaing everything, on a big scale and all the way to the tiniest of details, and you put it all together very well. Going into detail, and then backing up and explaining how it all applies, and what it basically means, like whats actually happening, or what its similar to. You lay it out the way it is and then make it relatable, palatable, understandable, and even fun. You rock dude! Thanks!
As much as i love love love these videos, i have a hard time remembering concepts and information so has anyone made any quizlets over any of the videos from CrashCourse? It doesn't even have to be biology. I'd love to be able to learn new things.
I'm making a playlist of the first videos I ever saw on my favourite channels and this was my first Crash Course video. :) My class watched it in biology in December 2013 because my teacher is a huge fan. It t lead to me discovering Hank and John Green on Vlogbrothers and joining Nerdfighteria.
Thanks to this video I got a 60% on my test. And that's a big plus for me cause I normally get a 40%. And I'm an A + student. This biology class is the first class I was failing. And I just found this video 4 am. So that's a big plus for me I know my next test I will score higher. Thanks so much. My teacher taught me nothing in a 3 hour class and I learned more in 10 minutes
You were wrong about one thing. You said that Hypertonic is when there's a greater concentration on the inside, while that's not true. There's a greater concentration on the inside of Hypotonic, not Hypertonic. That's what I've been taught.
no he's correct, if two solutions have unequal osmotic concentrations, the solution with the higher concentration is hypertonic, and the solution with a lower concentration is hypotonic. (concentration of solutes)
Hypotonic is when there are greater WATER inside the cell but he was talking about the concentration of SOLUTIONS so the solute in the solutions and Hypertonic has less WATER inside the cell than outside.
I'm currently in IB at Riverview High School. (Well, technically, I'm not in IB yet, since I'm a Freshman, but I've been accepted into the IB program, and I'll start in Junior year; until then, I'm in an advanced program for people in the same situation as me.)
right before this video i got a magic men live ad and then it jumped right into hank saying "hey, i didn't see you there. How long have you been waiting in this line?"
Just as a quick help, because i didn't quite understand Hanks explanation (with the example he names, with the salt water): Hypertonic : if the concentration of a solution is higher on the outside than it is on the inside (if they had reversed the process, placed a membrane filled with water in a saltwater solution, the salt water solution would have been hypertonic) Hypotonic : if the concentration of the solution is lower on the outside than it is on the inside. (With the experiment, the water outside of the membrane was hypotonic, with the salt water, inside the membrane having the higher solution of "salt per water"). Sources: my biology text book, Khan Academy ( www.khanacademy.org/science/biology/membranes-and-transport/diffusion-and-osmosis/v/hypotonic-isotonic-and-hypertonic-solutions-tonicity )
when he said "it's my favorite part of the show" i couldn't help but imagine him with a monocle and mustache like a kind sir. also could help imagining him with a british accent either XD
