If you’re like us, you love the sound of a brunch buffet. But not everything you eat at that glorious buffet is going to be turned into energy. Your body has to work with different forms of food in different ways. In this episode of Crash Course Anatomy & Physiology, Hank takes us through more about our metabolism including cellular respiration, atp, glycogenesis, and how insulin regulates our blood sugar levels.

Anatomy of Hank Poster:

Table of Contents
Cellular Respiration converts glucose into ATP 2:03
Glycogenesis converts glucose to glycogen 3:26
Lipogenesis converts glucose into triglycerides 5:58
Insulin regulates blood sugar levels 5:22


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CC Kids:



  1. If I could, I’d give this a million likes. I can’t like it enough. A single
    “like” is terribly insufficient. This video will be incredibly helpful to
    my students when we cover diabetic medications and cholesterol drugs (which
    of course, are only used when diet and exercise aren’t enough). Based on
    the responses I see here in the comments, it’s clear that many people have
    had experience with diabetes-related and nutritional issues. But that would
    be an entirely different CC series… I don’t suppose there are any
    diabetologists or registered dieticians out there who want to work on that

    • +Christopher Evans It would be nice if we could just tally up the numbers,
      but unfortunately calories aren’t created equal. The body breaks down
      different macronutrients using different chemical pathways unlike a
      calorimetric bomb, which uses heat to measure the amount of calories in a
      serving of food.

      It’s a good thing we aren’t calorimetric bombs as the temperature
      fluctuations would probably be pretty uncomfortable, but it does make
      nutrition more complex than counting calories…

    • +West996 When you’re full, your adipose tissue releases a hormone called
      leptin, which is referred to as the ‘satiety hormone’. Receptors in your
      hypothalamus detect this hormone, which responds by stopping the release of
      grehlin, which is the ‘hunger hormone’. That along with the stretching of
      your stomach lining gives you the sensation of being full. Some people can
      experience leptin resistance in which they overeat because they get that
      sensation of fullness. Hope this helps!

  2. carbohydrates increase your basal metabolic rate, this means that sugar are
    not very fattening and instead help you lose fat.

  3. Everyone is focused on that Rick and Morty reference but what I’M focused
    on is the missing TARDIS in the new channel art. Wasn’t there a TARDIS
    before? Where did it go?!?

    • I’m no doctor, but as a person with type 1 diabetes, I can say that carbs
      are not something you can eliminate like that from a diet. There’s a dang
      good reason people so crave sugar; it’s literally brain food, and
      proportionally, people are practically all brain compared to all animals.
      Yes, even Congress, as shocking as that may be.

  4. Also, don’t forget Insulin Resistance, a.k.a pre-Diabetes, which is sadly
    not much mentioned, and can be reverted if detected on time.

    • Starvation is worse in the long run. If you do it for too long, your brain
      isn’t able to work as effectively, because once it’s favored source of
      energy runs out, it’s forced to use a source it can’t synthesize as well.
      This source only allows it to use it 78% as efficient as the other source.
      If you wait even longer, and you could get ketosis, which is pretty scary.
      Also, if you look up the side effects of anorexia, well, they’re pretty
      risky too. (Which is, as you probably know, starving one’s self for
      appearance purposes, to the point where it becomes difficult to control and
      life threatening.) Not to mention, fats are used for hormones and such.
      They aren’t fun in excess, but they are useful – and so are the other
      nutrients that your body needs. Hence, starving them all away would not be
      safe or helpful. Your body needs fuel for all sorts of stuff, such as
      building some of it’s own components, D.N.A, energy, maintaining your brain
      efficiency and mood/hormones, etc. So the moral of the story is: there may
      be many ways to get rid of fat, but starvation isn’t the best in the long

    • Just a word of caution, starving to lose weight is like selling your soul
      for money. Once you starve, sure you’ll lose lots of weight, but lots of
      side effects will occur. Not to mention, once you start eating again, your
      body will freak out and will store everything as deep as they can; making
      you even fatter than before you starve yourself.

    • Nononononono. Do NOT starve yourself. What you need is a balanced diet:
      just eat enough to be satisfied, and get plenty of exercise. Talk to a
      doctor if you think you need to lose weight. We come in all shapes and
      sizes, so just be YOU sized. Ranting person out. DFTBA

  5. Only five trips to the buffet? Blasphemy, I need at least 7 or 8.

    On an unrelated note, I wonder why my clothing is shrinking.

  6. 6:47 Why LDL and HDL are called “LDL cholesterol” and “HDL cholesterol” if
    they aren’t cholesterol at all? I’m so confused.

  7. These videos are awesome.
    But you guys are doing the most annoying shit ever. Those speech-bubbles
    are nearly impossible to read along what Hank is saying.
    I mean c’mon. You pop those up while he is in the middle of a sentence so
    you can’t pause to read them. And the one at 4:22 was a fucking joke I hope.
    Just either say that information or at least give us a moment to read that

    • +kurtisdickinhand You must have not read my comment:
      Those bubbles start to appear at the beginning of a sentence and disappear
      at the end of one. Basically you have to pause in the middle of the
      sentence to read them. That usually gets confusing because making sense of
      what Hank says isn’t that easy anymore. So you have to listen to what Hank
      said, pause, rewind and then read the speech-bubble. Something that can be
      clearly avoided by just simply fucking saying what the speech-bubble reads
      or just adding this information in a different way.

      How do they think is this even gonna work? Like am I supposed to read while
      listening at the same time to get two different kinds of information?

  8. Thank you very much I really review all the information I take in the book
    ( 1-2 hours ) – in just less than 15 minutes!

  9. hmm. so if diabetes is the body unable to use or produce insulin
    efficiently, wouldn’t those with it be unable to store fat? it seems to be
    the opposite.

  10. lmao @ keep the portions to 5 plates at an all you can eat buffet
    hahahahahaha. I can barely get 2 plates down, unless one of those plates is
    full of delicious fatty bacon mmmmmmm bacon… aaaarrrrrhhhhhhh….????

  11. As usual, very informative episode, but you completely disregarded ketosis
    – on which I’d like to hear a bit :)

  12. At 3:00 there’s one hydrogen too much for the second stage to be a fructose
    derivate and consequently its upper little metabolite to be called a

  13. the first molecule you refer to as fat is actually glucose. fats are
    generally in a form of triglyceride plus fatty acid chains. This also need
    to be converted into AcCoa before it can actually be used for general
    oxidation. Just thought a small correction might be needed.

  14. I’m trying to learn the lymph system and immunity for school and it is so
    confusing. I hope you’re planning videos about that soon!

  15. thank u crash course
    but where’s white blood cells ? it’s part of blood , i know it have alot of
    informations like types of luckocytes , but i hope u make video in near

  16. “You can blame the law of conservation of energy.” But also, you should
    blame yourself for knowing that and ignoring it.

  17. It took me years of reading to get to understand the stuff that is so
    expertly depicted in this video. What an amazing presentation!

  18. It seems Hank skipped over the fact that Gluconeogenesis only is short term
    transitionary between Glucose metabolism to Ketone Metabolism which the
    brain can metabolise and potentially get a bigger energy yield from but
    slower to burn as gluconeogenesis even though can use Glycerol you require
    two glycerol molecules to produce glucose and the body attempts to conserve
    amino acids in the Early stages so it breaks down fatty acid chains into 3
    carbon and 4 carbon long chains of very reduced carbohydrates in the class
    of ketones, Acetone is the 3 carbon one and most of it does get wasted due
    to it volatility but it can be used by the brain still, and it also has
    several health benefits for people with certain conditions like epilepsy
    and bipolar as it actually increases GABA which is anti-epileptic and mood
    stabalising (Do not recommend ketogenic diets unless you are being medical
    monitored closely and have condition which have been shown to improve with
    ketosis, do not use ketogenic diet in place of medication it should be
    supplimentary and not replacement), the other ketones also have this effect
    but don’t get wasted the same due to less volatility though Acetoacetate
    does spontaniously decarboxylate into Acetone, and Beta Hydroxybutyrate is
    the most stable ketone and binds very well to the GABA receptor as GABA,
    GHB, and BHB all have a butyric acid backbone… This state of ketosis will
    remained til ether glucose is restored or the person runs out of fatty
    acids in which case the body reverts back to second degree of
    gluconeogenesis this time really hooking into the amino acids and this is
    where starvation starts to waste away muscle mass.

  19. I was in the hospital in July because my pancreas decided to go on vacation
    because of all the hard work. This is really good knowledge to know. I
    think we should all eat like we are diabetic to a degree.

  20. So today for breakfast i eat these little potatos and eggs with bacon
    inside. I go outside after everything I eat but today I’m not feeling it.
    is that bad that I didn’t go out?

  21. I feel bloaded after everything I eat. just happen to me one day. I thought
    “maybe it’ll go away tomorrow” and it didn’t
    So yeah people say I’m skinny but I don’t feel like it :/

  22. It’s nice to see that someone can make learning interesting for children.
    My little brother enjoys your videos and it helps him learn and elevate to
    a higher academic level, (BTW he’s in high school). Remember to keep up the
    good work man.

  23. The very last part is slightly incorrect. Weight loss is caused by the
    ketogenic state from cells not being able to use the insulin to, more or
    less, shuttle the glucose into the cell.

  24. informative vid, thx a lot.
    have u planned to make one on ketosis? i think this is missing – nowadays a
    lot of people cut carbs in their diet, especially fructose, to lose weight.
    keep it coming!

  25. Think we may need a better explanation on how the nutrients get into the
    cell through the capillaries. A link between the Biology CC and the Anatomy
    CC would be useful considering (at least around here) Anatomy classes have
    a section that links Bio to Anatomy, or Bio is a pre-requisite for Anatomy
    classes. It would also be useful to have a video that tracks digestion all
    the way down to the cellular level. Not to mention it would probably be as,
    if not more, entertaining as all the other videos done by Crash Course.
    Imagine the little nutrients with faces entering a cell via vesicle forming
    in the cell membrane, again with a little face on it. Please make it

  26. Wait… So is it correct in saying that if I eat less meat, I will have
    less cholesterol, therefore less transported and made into hormones, which
    makes me less manly because I don’t eat meat that often


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