These are tiny molecular machines, and they are doing this inside your body – right now. To understand why, we have to zoom out. Every day, in an adult human body, 50 to 70 billion of your cells die. Either they’re stressed, or damaged, or just old. But this is normal – in fact, it’s called “programmed cell death”. But, to make up for all these lost cells, right now, billions of your cells are dividing, essentially creating new cells. And that process of cell division, also called mitosis — well, it requires an army of tiny molecular machines. So, let’s take a closer look. DNA is a good place to start – the double helix molecule we always talk about. This is a scientifically accurate depiction of DNA, created by Drew Berry at the Walter and Eliza Hall Institute of Medical Research. If you unwind the two strands, you can see that each has a sugar-phosphate backbone connected to the sequence of nucleic acid base pairs, known by the letters A, T, G and C. Now, the strands run in opposite directions, which is important when you go to copy DNA. Copying DNA is one of the first steps in cell division. Here, the two strands of DNA are being unwound and separated by the tiny blue molecular machine called “helicase”. Helicase literally spins as fast as a jet engine! The strand of DNA on the right has its complementary strand assembled continuously. But the other strand is more complicated, because it runs in the opposite direction. So it must be looped out with its complementary strand assembled in reverse, section by section. At the end of this process, you have two identical DNA molecules, each one a few centimeters long, but just a couple nanometers wide. So, to prevent the DNA from becoming a tangled mess, it is wrapped around proteins called “histones”, forming a nucleosome. These nucleosomes are bundled together into a fiber known as chromatin, which is further looped and coiled to form a chromosome, one of the largest molecular structures in your body. You can actually see chromosomes under a microscope in dividing cells. Only then do they take on their characteristic shape. Otherwise, the DNA is more strewn inside the nucleus. The process of dividing a cell takes around an hour in mammals, so this footage is from a time-lapse. You can see how the chromosomes line up on the equator of the cell. Now, when everything is right, they are pulled apart into the two new daughter cells, each one containing an identical copy of DNA. Now, simple as this looks, the process is incredibly complicated and requires even more fascinating molecular machines to accomplish it. So, let’s look at a single chromosome. One chromosome consists of two sausage shaped chromatids, containing the identical copies of DNA made earlier. Each chromatid is attached to microtubule fibers, which guide and help align them in the correct position. The microtubules are connected to the chromatid at the kinetochore, here colored red. The kinetochore consists of hundreds of different proteins working together to achieve multiple objectives. In fact, it’s one of the most sophisticated molecular mechanisms inside your body. The kinetochore is central to the successful separation of the chromatids. It creates a dynamic connection between the chromosome and the microtubules. For a reason no one’s yet been able to figure out, the microtubules are constantly being built at one end and deconstructed at the other. While the chromosome is still getting ready, the kinetochore sends out a chemical “stop” signal to the rest of the cell, shown here by the red molecules, basically saying, “this chromosome is not yet ready to divide.” The kinetochore also mechanically senses tension. When the tension is just right, and the position and attachment are correct, all the proteins get ready, shown here by turning green. At this point, the stop signal broadcasting system is not switched off! Instead, it is literally carried away from the kinetochore, down the microtubules, by a dynein motor – that’s the walking guy. This is really what it looks like: it has long “legs” so it can avoid obstacles and step over the kinesins, molecular motors that walk in the opposite direction. Personally, I’m astounded by these tiny molecular machines, how they’re able to routinely and faithfully execute their functions billions of times over inside your body at this exact instant. I’m also amazed by the scientists who were able to work out how this happens in such detail that we could create realistic depictions of them, like you saw in the animations in this video. But, perhaps, the most amazing thing is just how much is left to be discovered, like, figuring out how exactly the chromatids are pulled to opposite ends of the cell. There is still so much that we don’t quite know. You know, what I find exciting is, that in science fiction, for decades, we’ve been writing about tiny nanobots that will be injected into our blood streams that can heal us. But, what this suggests, the existence of these tiny molecular machines inside us, it suggests that there isn’t a physical limit that would prevent that. And so, I think it’s pretty likely that, in future, we will be able to develop our own tiny molecular machines that will be able to repair our bodies better than they can repair themselves.

100 thoughts on “Your Body’s Molecular Machines”

  1. Of all the brilliant minds in all of history, who could engineer such a design? I guess random chance of life from space soup is a better engineer than any scientist there ever was. Even scientists agree than random chance—so random that there would be trillions of times greater that Godzilla created the Earth versus alphabet space soup.

  2. According to evolution life started with a single cel. Dna and dna copying is required for the first stage of evolution, that is ways to advanced to spontaniously form

  3. You just stole all this from the ted talk, (you probably got permission but it is not original you should have given more credit to the talk

  4. I think it's interesting how many people in comments don't understand how evolution works and immediately assume some god did it. (which god? I assume it's the one you were told to believe in!)
    If only they could grasp the billions of years, tens of trillions of iterations it took to arrive at these marvelous machines we have today.
    Not by pure chance, but by the simple process of replication and natural selection.

  5. It's amazing how this brilliant, excellent, and complex animation required intelligent input, but that the actual biological activities that are being described did NOT.

  6. It is amazing how complex our body are, remembering it is there in the first place due to natural selection, which actually just a big coincidance

  7. ロボットは人間より優れていますか? いいえ、私たちはそれぞれこれらのロボットの銀河です。

  8. Amazing discoveries! And imagine, all these machinery happened by chance billions of years ago! And all the data that's necessary to build all this suddenly appeared from nowhere out of dead matter, ha!

  9. So my question is, how deep can we look into these things, what makes the molecular machines themselves tick? And then whatever makes them tick and so on. Then, where does it begin, and end?

  10. Scientism, Believe like your job depends on it. Just pour lots of Hydrogen in space and it'll turn into human beings all by itself.

  11. Can anyone tell me, with a straight face, that this evolved from lightning striking the proverbial primordial soup? None of these nano machines have ears, eyes or brains, yet, they know EXACTLY what to do, when to stop doing it and when to start up, again. Yep, just by chance, I'm sure. If you actually believe that, you have a billion times more faith than I could ever have.

  12. A ciência está tão avançada, mas não consegue avançar na cura de quase todas as doenças, só existem remédios para mante-las.

  13. How does the movement happen? Such as Helicase. What is causing the spinning, where is the energy coming from? What are the physics behind the movement?

  14. i think the tubules are always being built and then deconstructed at one side is so that the damage to the tubules "gets repaired" while the damaged part will eventually be deconstructed, and replaced with a healthy part

  15. Think about it, they do all this automatically, they dont think about, they just do it in harmony on a massive variable scale. Completely automatic, just like you move, breathe and think…

    Heres something you can do now : Move your index finger and ask yourself, how do i as a conscious being do it? Do you really do it at all or does it do you ?

  16. Are there any bunch of cells within human body, which don't die untill you die? If not, then the sense of Identity must be emergent.

  17. Watching this , reminded me of the Book Collection in the 1990’s it was called “How My Body Works” – It was so much fun to read because of all the comedic illustrations/pictures .


  18. Of all the garbage taught in schools, touting the creation of this complexity as nothing but mere chance, not as a hypothesis but unquestionable truth, is a dangerous ignorance of evidence.

  19. At this level, what is only physical, automatic, mechanic and inert, and what is "alive"? What "unites" all the cells of the body in a single consciousness, the "self" ? (the brain, but moreover). Are there things we don't know about DNA which link the molecules that we see in this video ? Are the electricals messages of the brain, the nerve center, conscious or unconscious, taking an important part in the processus of growth and the phenomena that we see in this video? Is there a truth hidden in bio-chimistry ?
    We need both philosophy and biology here.

  20. nobody has figured out why the microtubules are created on one end and destroyed on the other? seems like it has a simple answer to me. probably because when the rate of creation slows or destruction speeds up, the tubes shorten thus pulling the chromosomes apart.

  21. Dafuq did I just watch :O Fascinating. How do they now what is their purpose? What are those exactely. If they build our cells what builds them? Do they have also some kind of dna? There is a blueprint somewhere for sure. I need to dig in more because its to cool.

  22. with such complicated yet amazing things going on inside each one of us, you wonder why some human are just total buttholes

  23. I have a background in computer sciences, and the section at 5:00 rings a bell for me.
    Networks do this all the time, puts together packets and sends them from point A to point *B*.
    Then there is a validation process the packets have to meet in order to be considered valid and to eradicate any error.
    So when the little guy is walking over counting the points, and the others are moving along the sides validating the elements, and information BEFORE it separates, it makes perfect sense to me why these processes are there. It's a program. A very complex, 3-dimensional program performed at the speed of a jet engine, trillions of times. And at the end each function is created, fits and connects to the whole, producing – one of us; and keeps us under a program of controls to manage the cellular transformation we undergo in a lifetime. Frankly, breathtaking.

  24. hi, Derek.
    popular model of muscle contraction is wrong. can you verify this?

  25. As a design engineer in the field of electronics and software for 45 years, I see clear evidence of an intelligence that far surpasses human comprehension. These amazing “functional proteins”, usually referred to as “machines”, are extremely specific long chains of 20 amino acids, with typically over 150 amino acids per protein molecule. There are over 10^77th power non-functional combinations for every functional protein.
    What makes it far more mind boggling is that every amino acid in the chain must have the same optical polarity (chirality). Every amino acid except glycine can have two polarities (like mirror images), and only one of the forms, the “L-configuration”, can be used in a functional protein. If a single amino acid has the wrong polarity, the protein does not function. We have no idea how protein molecules form with all the amino acids having only one polarity. It’s one of the greatest mysteries of life. And it’s true for every living cell on earth.

    In order for the simplest cell to exist, it takes hundreds of different types of these extremely rare functional proteins (machines), each in large quantities, to come together at the exact same time and microscopic point in space, along with the functional cell membrane and many other components. The mathematical odds against the first living cells appearing by random chemical reactions in a pool of “pre-biotic soup” are overwhelming.
    No chemist or biologist in the world has any idea how this could have happened by non-intelligent materialistic processes. It’s so unlikely it would be virtually impossible, even in an eternal universe.

    The more we know about life, the greater these mysteries become. This is only one of many examples. We now have far less scientific evidence than ever to support an atheistic world view of the origin of life. Yet, most people are taught the opposite in the American public schools because of government control. It’s not “politically correct” to mention the idea of a Creator in public schools.

  26. think's the haven. that's why ALBERT EINSTEIN answerd To ESTER SALAMA (journalist in nottigen Berlin university) master "why you are running round the world?.the answer is this:il want To now how god as created the world"

  27. How you could speak about "programming" and "machines" without mentioning design by a creator is beyond me. You have all the information you need to understand that we are not creatures of chance and evolution, but yet, you don't.

  28. Evolution is valid. No doubt about that. You can search the evidence in fossil records (evolution of whales for example). All we can say in science is that there were highly unlikely impulses called "random mutations" that lead to this kind of mind blowing complexity.

  29. This great video animation reminds me what I read in the book THE ALIEN INTERVIEW, in which Airl describes how the great Galactic Corporations like Arcadia create and program life and living entities or species. Now I understand too much better how they program their bio algorithms. Also, it proves my assumption that every single process in our body corresponds to a specific bio algorithm of which there are billions working in synchronicity. There's too much left to research and discover.

  30. Reminds me of a shower thought I had some time ago, in that humanity are basically the perfect imperfect organic self-aware robot, with the only major flaw in causing its demise is cell degradation, preventing it from living for forever.

  31. "We can prepare our own tiny molecular machines that could repair our body better than we could"!!!!!! And there is where you are very very wrong!!!!!

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