Articles, Blog

Fermentation

August 16, 2019


Captions are on! Click CC at bottom right to turn off. When I was a kid, swimming was one of my favorite
things to do. I was on the swim team starting when I was
four years old and then on and off throughout grade school, although I wasn’t especially
fast. I just loved the water. I used to dream that there was a way I could
be like a fish. When I was little, I had a misconception that
fish didn’t need oxygen. Later on, I learned that, no, most fish have
gills that allow them to extract the oxygen, which they need, from the water. So then I just thought it’d be really cool
if I just had gills. But, alas, no gills for Pinky. Oxygen is a really big deal—so many organisms—from
fish to plants to humans—need oxygen. And yes, even though plants make oxygen in
photosynthesis…they still perform cellular respiration and therefore plants still need
oxygen themselves. There’s often a misconception that plants
don’t need oxygen; that’s just not true. So why do these organisms need oxygen? It’s similar to why you need oxygen. If you’ve ever wondered why you need to
breathe, which is done by the respiratory system in your body, zoom into the cell level. Cells in your body use the oxygen you inhale
to perform cellular respiration. The formula here requires inputs, otherwise
known as reactants, to make ATP. And oxygen is one of those reactants in the
overall equation that is needed to break glucose down in forming ATP. Why ATP? ATP stands for adenosine triphosphate. It is action packed with three phosphates. It has the ability to power many cellular
processes. Typically it’s coupled to other things that
it may be powering. Now after losing the phosphate, the molecule
is ADP, adenosine diphosphate, because it has 2 phosphates. In cellular respiration though, there are
enzymes that can add another phosphate to it and convert it back into ATP again. This particular formula of cellular respiration
is aerobic, meaning overall, it requires oxygen. It is pretty complex, and we have a video
breaking down steps. But that’s not what this video is about. This video is about what happens when there
is no oxygen. Because cells still need to make their ATP. So what kind of cells can handle the no oxygen
thing? Well many types of bacteria can. Many types of archaea. Yeast, which is a fungus that could be helpful
like making your bread rise. Your muscle cells can, for a while anyway. These are all just some examples. Now these organisms handle the lack of oxygen
in different ways. Some organisms such as some types of bacteria
or archaea can do anaerobic respiration— they can continue to perform glycolysis, krebs,
and the electron transport chain just like aerobic cellular respiration. But since there is no oxygen to be that final
electron acceptor at the end of the electron transport chain, they use something else. Sulfate for example. These organisms are specifically adapted to
be able to use a different electron acceptor in this anaerobic respiration. Another option is the organism may just stick
with doing just glycolysis, which doesn’t require oxygen, and then the addition of some
way to get their NAD+ back—-we’ll talk about what that means in a minute. This process is called fermentation and that’s
what we’re going to focus on. Fermentation is a way to be able to handle
the little to no oxygen issue: it allows for glycolysis to happen and for glycolysis to
keep going. That means making ATP when there is no oxygen. And while you won’t make as much ATP in
this process as you would aerobic cellular respiration, you can’t be too picky when
oxygen isn’t around. Recall what glycolysis is from our cellular
respiration video: in glycolysis, you take glucose—a sugar—and it gets converted
into pyruvate. This takes a little ATP cost to actually start
it up, but overall, you make 2 net ATP per glucose molecule and you also produce 2 NADH. What’s that? Recall that NADH is a coenzyme and an electron
carrier. We also need to mention that NADH didn’t
just *poof* appear as a product. No, because NAD+ actually was reduced to NADH
when it gained electrons. And if the words reduced and oxidized are
confusing…you can remember the famous LEO GER mnemonic: Lose electrons=oxidized. Gained electrons=reduced. So NADHNAD+ is oxidation because it loses
electrons and NAD+NADH is reduction because it gains electrons. Now NADH, the electron carrier, would normally
be delivering the electrons gained to the electron transport chain if this was aerobic
cellular respiration. Once losing their electrons, NADH would be
oxidized into NAD+ and be ready to be involved all over again in glycolysis. But there’s no electron transport chain
step in this fermentation process. So we’ve got to regenerate the NAD+ somehow—NAD+
is needed here after all for glycolysis to continue. Fermentation therefore adds another little
step to the end of glycolysis—a step to help regenerate NAD+. This happens because fermentation allows NADH
to give its electrons to an electron acceptor which, in the two fermentation examples we
are going to give, will either be a derivative of pyruvate or pyruvate itself. So here we go with two types of fermentation
which both result in different products from pyruvate. Alcoholic fermentation: as done by some types
of yeast. So first glycolysis which yields 2 net ATP,
2 pyruvate, and 2 NADH. Now we need the step to regenerate the NAD+
so we can keep doing glycolysis. The 2 pyruvate is used which will ultimately
produce carbon dioxide and 2 ethanol (alcohol), but the derivative of pyruvate shown here,
acetaldehyde, can act as an electron acceptor in this process so that the 2 NADH can be
oxidized to 2 NAD+ so that glycolysis can start all over. Since ethanol (alcohol) is a waste product
in this process.Yeasts also can do alcoholic fermentation in making bread, and the carbon
dioxide product we mentioned is involved with helping the bread rise! The tiny amount of alcohol produced in the
short fermenting time of bread will evaporate in the baking process. Lactic acid fermentation: as can be done by
cells such as your muscle cells for example! While your muscle cells can do aerobic cellular
respiration, they can shift to lactic acid fermentation if they experience an oxygen
debt. This could happen if you are working out very
intensely where your blood is unable to deliver a sufficient amount of oxygen to them for
their demand. Just like with alcoholic fermentation, we
start with glycolysis that yields 2 net ATP, 2 pyruvate, and 2 NADH. But now we need the step to regenerate the
NAD+, and this step is a bit different from alcoholic fermentation. The 2 pyruvate on the reactant side will ultimately
yield 2 lactate. The pyruvate can act as an electron acceptor
allowing NADH to be oxidized to NAD+ so that glycolysis can start over. By the way, this lactate product or specifically
its other form lactic acid, has often been blamed for the muscle soreness that occurs
the day after intense exercise- in many of my teaching years this was the hypothesis
with this- but actually there’s some recent research that may dispute this product as
the cause of muscle soreness. Check out our further reading suggestions
in our video details to learn more! Lactic acid fermentation is also done by bacteria
that are involved in making yogurt and lactic acid can contribute to its sour taste. So overall, fermentation is a pretty remarkable
process. Although, it does make us appreciate oxygen
because despite how absolutely awesome fermentation may be….…it just can’t make as much
ATP as aerobic cellular respiration. Well, that’s it for the Amoeba Sisters and
we remind you to stay curious!

100 Comments

  • Reply Amoeba Sisters April 30, 2018 at 8:53 pm

    This is a quick reupload—sorry about that! We had an earlier version posted just an hour ago, but we noticed a place in the video that had the word NADH instead of NAD+. A typo that would really bother us if it caused any confusion! Fixed now 🙂

  • Reply Maluak April 30, 2018 at 11:11 pm

    Fermentation, I love it, because it can generate alcohol^^

  • Reply Roboglobe April 30, 2018 at 11:50 pm

    You guys are cool beans.

  • Reply Kara Reichert May 1, 2018 at 1:58 am

    The Office Space reference is making my day!!! Haha!!!

  • Reply DragonMage May 1, 2018 at 2:07 am

    I have my biology EOC tomorrow and I'm studying oof

  • Reply Michelle Lee May 1, 2018 at 11:05 am

    omg that pic with the NADH hugging the electrons is so cute…

    (But that would be NADH-)
    Anyways, if anyone is confused on why NADH is the reduced form, just remember that when a proton (+) gains an electron, it becomes an H.

  • Reply TheBrodsterBoy May 1, 2018 at 1:14 pm

    Still waiting on that prions video

  • Reply A Girl Online May 1, 2018 at 5:50 pm

    I learnt OIL RIG. Oxidize is lose and reduce is gain

  • Reply georgehenna May 1, 2018 at 9:10 pm

    I'm LATE !!! A DAY LATE!📩📨 My sincere apologies my fellow single-celled companions and I vow a solemn oath to like this video for your inconvenience. The video is awesome by the way. Best of luck for the future and I hope that with the help of Endosymbiotic Theory, you guys and your channel will grow to greatness. 😉🧠😉😄

  • Reply SuperSoldier 24 May 2, 2018 at 2:01 am

    The amoeba sisters are Thicc

  • Reply SuperSoldier 24 May 2, 2018 at 2:03 am

    A

  • Reply Zhangus May 2, 2018 at 2:34 pm

    BAD VIDEO >:(

    Jk

  • Reply Zhangus May 2, 2018 at 2:35 pm

    have exams tmr 🙁

  • Reply NOBEL DJ May 3, 2018 at 12:20 am

    ahhhh 12 days left for us need more videos for the marathon AP BIO TESTS ON 14TH!

  • Reply Beth Kelley May 3, 2018 at 1:02 am

    Ohhh oh-ho, wait 'till the Amoeboy Advance comes out so you can play Pokémon Blood Red and Chlorophyll Green!

  • Reply Lauren Chiasson May 4, 2018 at 3:10 am

    A video diving more deeply into each of the main body systems would be great! If there's an Amoeba Sisters video for the subject I want, I always watch that one!

  • Reply Misha Petrov May 5, 2018 at 2:07 pm

    Super helpful for my studying! I have a Bio EOC soon and I have never understood this process till now! Also I love theses Videos.

  • Reply Michael Evans May 7, 2018 at 1:12 am

    I followed you guys on Twitter. We watch you in my science classroom. I like you two.

  • Reply Khadija May 7, 2018 at 6:03 am

    Im studying for my MCAT & I literally lovee watching your videos because you make them so enjoyable. Thank you!

  • Reply Run Fire Studios May 7, 2018 at 11:51 am

    Wow, cool videos and very creative visualization and sense of humor.. Keep up the good work!

  • Reply Hi.Im.Grant May 9, 2018 at 4:16 am

    https://www.change.org/p/amoebasisters-gmail-com-petition-to-create-the-amoeba-sisters-extended-universe-aseu

    Please sign this petition if you want Amoeba Sisters to reach a higher level

  • Reply Isaac Clark May 9, 2018 at 9:13 pm

    you guys are the best. You teach better than my biology teacher. I wish you guys had a school. I appreciate the time and effort you guys put into these videos. They help me so much when I am trying to study or I cant figure out a concept. Thanks for all your work 🙂

  • Reply Josef Stalin May 9, 2018 at 9:29 pm

    My biology teacher tested me on this once. I hate his liver, with some fava beans, and a nice Chianti.

  • Reply TheTexasOOF Gamer May 12, 2018 at 3:33 am

    I shoot 35mm film
    Film is the best in analog photography

  • Reply Casilda García May 12, 2018 at 11:34 am

    Fantastic!

  • Reply Daniel Mejia May 16, 2018 at 12:58 pm

    Having a bio eoc tomorrow. So this helps.

  • Reply Megan Kennedy May 16, 2018 at 11:47 pm

    I have biology keystones tomorrow and i’m basically binging all your videos. they are really helpful and the information is delivered in a way that is memorable, which i really appreciate. thank you

  • Reply Mckallum Malanowski May 18, 2018 at 1:38 am

    These videos are so helpful for finals
    Thank you!

  • Reply TESCO May 18, 2018 at 2:11 am

    Not cool you American scum

  • Reply Geogia.E Gray May 21, 2018 at 10:06 am

    if you find the mnemonic LEO GER difficult try OIL RIG
    O – OXIDATION
    I – IS
    L – LOSS

    R – REDUCTION
    I – IS
    G – GAIN

  • Reply Azmi Wan June 26, 2018 at 6:15 am

    good video its really help me for my exam!

  • Reply Rigzin Oshoe July 1, 2018 at 9:15 am

    This vid sux

  • Reply Ms X July 5, 2018 at 4:05 pm

    Thank you! You guys help me a lot 💕

  • Reply Roxana de la Cruz July 22, 2018 at 9:43 pm

    ¡Estos vídeos son geniales! 👍

  • Reply naturalchiremedies Natural Chinese remedies August 20, 2018 at 1:54 am

    Your video is so cute!!!! Love it. So happy to learn with your video.

  • Reply Kaley & Emily September 6, 2018 at 11:27 pm

    pls don't ever stop making videos. thank you

  • Reply mohammad rasel September 21, 2018 at 8:07 am

    This was great, been searching for "function of mitochondria in eukaryotic cells" for a while now, and I think this has helped. You ever tried – Miyason Mitochondria Masker – (do a search on google ) ? Ive heard some incredible things about it and my buddy got cool success with it.

  • Reply LolitsLiza September 30, 2018 at 9:18 pm

    Thank you SO MUCH for these videos..I don't know what I'd do without them to help me understand all this shit lol

  • Reply Latinbrother2k12 October 1, 2018 at 1:47 am

    This is so helpful!!! I have a quiz on this on Monday and a test on this on Wednesday as well!!! YOU GUYS ARE MY SAVIORS!!!!!!!!!

  • Reply Kirsten Negri October 3, 2018 at 7:27 am

    Thank you thank you thank you thank you thank you

  • Reply BasicNerd October 7, 2018 at 9:50 am

    I love your videos. They're so cute.

  • Reply Melynda Grimes October 9, 2018 at 11:06 pm

    i LOVE swimming !

  • Reply jam34786 October 23, 2018 at 1:45 am

    I'm sorry you never got your gills science lady. Good video though! 🤗

  • Reply Genesis Shuler October 24, 2018 at 6:32 pm

    I have a midterm tomorrow and your channel is helping me. Thank you I truly hope I'm able to process all of this. 😊

  • Reply Kaelynn Herbon October 26, 2018 at 12:54 am

    This channel and Hank Green's "Crash Course" saving my biology grade

  • Reply Adrienne Janzen October 29, 2018 at 6:40 pm

    When I read my micro textbook, my inner voice sounds like you because your cadence and tone make learning easier! So, thanks!

  • Reply Martha Schissler October 30, 2018 at 1:36 pm

    Just wondering how prokaryotes (bacteria and archeae) perform Krebs and Electron Transort chain without mitochondria? Thanks!!!

  • Reply Bubbles3361 October 30, 2018 at 4:38 pm

    I really love your videos, they are so funny and helpful!

  • Reply Sultana Jabeen October 31, 2018 at 12:34 am

    I love your videos, i have a quiz on stuff like this and this is helping me for it. Mabye make some simpler videos for grade 7 or 8’s ( Like me) Who dont understand most of it

  • Reply Mori -Senpai November 5, 2018 at 2:41 pm

    I’m just here for the answers to the worksheet

  • Reply poke fan November 7, 2018 at 5:52 am

    Nnniiiicccceeee video

  • Reply Rithwik Sharma November 12, 2018 at 11:38 am

    diff to understand

  • Reply alwayswinning97 November 12, 2018 at 8:13 pm

    how does NAD+ oxidize to NADH without oxygen? what am i missing?

  • Reply Becky Sawyer November 13, 2018 at 1:27 am

    I found human petunia 0:43

  • Reply Left Lemur November 13, 2018 at 4:58 pm

    Thank you so much this will help me in my quiz tomorrow.

  • Reply SAB3R November 14, 2018 at 3:14 pm

    Ah I don't understand anything except cringy drawings if u agree leave a like

  • Reply Clorox Bleach December 2, 2018 at 12:44 pm

    I should just kill myself

  • Reply CESAR SMITH December 4, 2018 at 5:21 pm

    Whadda u mena brother dawg 360 oog booga bromie dawg

  • Reply Husa Almahanna December 5, 2018 at 5:05 pm

    I also love SWIMMING!!! AND science!!!

  • Reply Plamen Velkov December 5, 2018 at 5:28 pm

    Thanks

  • Reply KADEN KERN December 7, 2018 at 4:04 pm

    if you like it hit like butten.

  • Reply KADEN KERN December 7, 2018 at 4:08 pm

    my like butten

  • Reply Mario Geis December 15, 2018 at 12:55 pm

    Aber Vorsicht; ist Minze drin !

  • Reply MCWizard December 15, 2018 at 8:11 pm

    this makes me

  • Reply Rohit Mantramurti December 17, 2018 at 3:55 am

    subscribe to pewdiepie

  • Reply KaiserTheDemon December 17, 2018 at 3:33 pm

    I appreciate your videos, thank you.

  • Reply danofn December 17, 2018 at 9:54 pm

    well thank you molnar…..

  • Reply HB 5 January 5, 2019 at 11:59 am

    You just reduced my 1 week study schedule to a 1 hour of me watching your videos. It was worth it

  • Reply psalm91rdwlkfpgrl January 19, 2019 at 6:25 pm

    In "The 'Tail' Begins" by Jae Byrd Wells, 61 individuals are experimented on by a mad scientist and turned into Human Electric Cave Catfish (Hecc for short). They were basically modern-day mermaids. You talking about wishing you had gills made me think of that. It's a good story; you may enjoy it 😀

  • Reply Naqib Shami January 23, 2019 at 5:21 am

    Thanks

  • Reply Creative Animation Studios January 24, 2019 at 3:38 pm

    I needed this for a seince fair

  • Reply Archana Soni January 29, 2019 at 5:35 am

    How cute these videos are😍😍😍 one of the best presentation I have ever seen…❤️ Well done.

  • Reply P3_Sizzle February 1, 2019 at 7:52 pm

    Is It Just Me Or Does She Sound Like She Had A Bit Too Much To Drink. Just Me, Okay

  • Reply O-Rum Cha February 12, 2019 at 2:58 am

    At 6:05, does she say electronic scepter or electron receptor?

  • Reply Spicy Cat February 12, 2019 at 12:59 pm

    Fun fact: your heart and lungs are connected. Your heart pumps not oxygenated blood into your lungs to make them oxygenated.

  • Reply The LOL Minecrafter February 14, 2019 at 5:41 pm

    Oh my lord, that OfficeSpace reference at 3:29…. XD

  • Reply The LOL Minecrafter February 14, 2019 at 5:44 pm

    Also, OIL RIG is easier.
    Oxidation
    Is
    Loss (of electrons)

    Reduction
    Is
    Gain (of electrons).

  • Reply sheldy. ham February 20, 2019 at 5:27 am

    still 100% lost

  • Reply aaquib608 March 2, 2019 at 3:23 pm

    You have a creative way to teach us concepts that lasts in our mind for long😃😄. Claps for your works😊

  • Reply SanguinaryStrife March 12, 2019 at 2:16 am

    This video is terrible, you jump all over the place, you're not explaining where in the cell the cycles take place. You took too much time animating your voice and making these cartoons, you're missing some important facts. Thumbs down.

  • Reply Madison Logan March 25, 2019 at 4:41 pm

    Thank you so much for taking your time and making all of these videos! I am a visual learner and it makes everything so easier to learn! You guys rock!

  • Reply Royce Kamilchu April 4, 2019 at 5:39 pm

    cute:)

  • Reply Ren April 27, 2019 at 11:32 am

    Difference between Anaerobic respiration and fermentation?

  • Reply Kelly Wan April 28, 2019 at 10:42 am

    I always do OIL RIG: oxidisation is loss, reduction is gain.

  • Reply dwij mehta May 2, 2019 at 4:51 pm

    Please make vedios on glycolysis,Krebs cycle,c-3,c-4 cycle etc physiological process in plants

  • Reply Alyazia Alamire May 11, 2019 at 6:52 pm

    Thank you very much 😭🖤🖤

  • Reply Z小 May 11, 2019 at 11:45 pm

    I have a exam Monday thanks

  • Reply Elijah Helm May 13, 2019 at 9:06 pm

    oml, borg reference

  • Reply 주현진 May 19, 2019 at 3:15 pm

    So easy to understand but can you explain a little bit more..? ( I studied this with my exam but some little parts were missing…)

  • Reply jana May 22, 2019 at 2:33 pm

    the love and thankfulness i have for you!!!!!!!!

  • Reply Noof720 May 25, 2019 at 12:10 pm

    Im studying for my Biology Exam and this is very helpful. Thank you so much

  • Reply Sashane Campbell June 6, 2019 at 1:02 am

    I have a end of year exam and your videos a doing a great job it allows me to understand the lesson more. Please continue❤

  • Reply Manya M Kumar June 6, 2019 at 4:24 am

    Loved the cute amoeba sisters In the video!!!! After seeing the video I feel textbooks look so boring…..

  • Reply Monica Blindheim June 12, 2019 at 10:51 am

    You rock!

  • Reply Chandana Ranga June 19, 2019 at 5:45 am

    👌👌👌👌😊

  • Reply Omega Fern June 19, 2019 at 7:54 pm

    I luv u guys

  • Reply Gambit Slots June 25, 2019 at 2:44 am

    Interesting video. Although I had to pause it a few times to YouTube what is and some of the various words you used!

  • Reply Raya Kelley July 7, 2019 at 4:31 pm

    whew

  • Reply ಖอื กลอ9 DruΜΜεr Tuskegee July 11, 2019 at 9:20 am

    1:10 _%%£$€%&*₩^*)฿฿฿^&&€¥£¥¥£^$#@><□□●

  • Reply Tarantinopi pp July 13, 2019 at 2:05 pm

    You know, vegans should eat fermented plants as cows do to get all nutrients of plants

  • Leave a Reply