English subtítols

← The wonders of the molecular world, animated

Some biological structures are so small that scientists can't see them with even the most powerful microscopes. That's where molecular animator and TED Fellow Janet Iwasa gets creative. Explore vast, unseen molecular worlds as she shares mesmerizing animations that imagine how they might work.

Obtén el codi d'incrustació
43 llengües

Showing Revision 7 created 04/13/2020 by Erin Gregory.

  1. I live in Utah,
  2. a place known for having
    some of the most awe-inspiring
  3. natural landscapes on this planet.
  4. It's easy to be overwhelmed
    by these amazing views,
  5. and to be really fascinated by these
    sometimes alien-looking formations.
  6. As a scientist, I love
    observing the natural world.
  7. But as a cell biologist,
  8. I'm much more interested
    in understanding the natural world
  9. at a much, much smaller scale.
  10. I'm a molecular animator,
    and I work with other researchers

  11. to create visualizations
    of molecules that are so small,
  12. they're essentially invisible.
  13. These molecules are smaller
    than the wavelength of light,
  14. which means that we can
    never see them directly,
  15. even with the best light microscopes.
  16. So how do I create
    visualizations of things
  17. that are so small we can't see them?
  18. Scientists, like my collaborators,

  19. can spend their entire
    professional careers
  20. working to understand
    one molecular process.
  21. To do this, they carry out
    a series of experiments
  22. that each can tell us
    a small piece of the puzzle.
  23. One kind of experiment
    can tell us about the protein shape,
  24. while another can tell us
  25. about what other proteins
    it might interact with,
  26. and another can tell us
    about where it can be found in a cell.
  27. And all of these bits of information
    can be used to come up with a hypothesis,
  28. a story, essentially,
    of how a molecule might work.
  29. My job is to take these ideas
    and turn them into an animation.

  30. This can be tricky,
  31. because it turns out that molecules
    can do some pretty crazy things.
  32. But these animations
    can be incredibly useful for researchers
  33. to communicate their ideas
    of how these molecules work.
  34. They can also allow us
    to see the molecular world
  35. through their eyes.
  36. I'd like to show you some animations,

  37. a brief tour of what I consider to be
    some of the natural wonders
  38. of the molecular world.
  39. First off, this is an immune cell.
  40. These kinds of cells need to go
    crawling around in our bodies
  41. in order to find invaders
    like pathogenic bacteria.
  42. This movement is powered
    by one of my favorite proteins
  43. called actin,
  44. which is part of what's known
    as the cytoskeleton.
  45. Unlike our skeletons,
  46. actin filaments are constantly
    being built and taken apart.
  47. The actin cytoskeleton plays
    incredibly important roles in our cells.
  48. They allow them to change shape,
  49. to move around, to adhere to surfaces
  50. and also to gobble up bacteria.
  51. Actin is also involved
    in a different kind of movement.

  52. In our muscle cells, actin structures
    form these regular filaments
  53. that look kind of like fabric.
  54. When our muscles contract,
    these filaments are pulled together
  55. and they go back
    to their original position
  56. when our muscles relax.
  57. Other parts of the cytoskeleton,
    in this case microtubules,

  58. are responsible for long-range
    transportation.
  59. They can be thought of
    as basically cellular highways
  60. that are used to move things
    from one side of the cell to the other.
  61. Unlike our roads,
    microtubules grow and shrink,
  62. appearing when they're needed
  63. and disappearing when their job is done.
  64. The molecular version of semitrucks

  65. are proteins aptly named motor proteins,
  66. that can walk along microtubules,
  67. dragging sometimes huge cargoes,
  68. like organelles, behind them.
  69. This particular motor protein
    is known as dynein,
  70. and its known to be able
    to work together in groups
  71. that almost look, at least to me,
    like a chariot of horses.
  72. As you see, the cell is this incredibly
    changing, dynamic place,

  73. where things are constantly
    being built and disassembled.
  74. But some of these structures
  75. are harder to take apart
    than others, though.
  76. And special forces need to be brought in
  77. in order to make sure that structures
    are taken apart in a timely manner.
  78. That job is done in part
    by proteins like these.
  79. These donut-shaped proteins,
  80. of which there are many types in the cell,
  81. all seem to act to rip apart structures
  82. by basically pulling individual proteins
    through a central hole.
  83. When these kinds of proteins
    don't work properly,
  84. the types of proteins
    that are supposed to get taken apart
  85. can sometimes stick together and aggregate
  86. and that can give rise
    to terrible diseases, such as Alzheimer's.
  87. And now let's take a look at the nucleus,

  88. which houses our genome
    in the form of DNA.
  89. In all of our cells,
  90. our DNA is cared for and maintained
    by a diverse set of proteins.
  91. DNA is wound around proteins
    called histones,
  92. which enable cells to pack
    large amounts of DNA into our nucleus.
  93. These machines
    are called chromatin remodelers,
  94. and the way they work
    is that they basically scoot the DNA
  95. around these histones
  96. and they allow new pieces of DNA
    to become exposed.
  97. This DNA can then be recognized
    by other machinery.
  98. In this case, this large molecular machine
  99. is looking for a segment of DNA
  100. that tells it it's
    at the beginning of a gene.
  101. Once it finds a segment,
  102. it basically undergoes
    a series of shape changes
  103. which enables it to bring in
    other machinery
  104. that in turn allows a gene
    to get turned on or transcribed.
  105. This has to be a very
    tightly regulated process,
  106. because turning on the wrong gene
    at the wrong time
  107. can have disastrous consequences.
  108. Scientists are now able
    to use protein machines

  109. to edit genomes.
  110. I'm sure all of you have heard of CRISPR.
  111. CRISPR takes advantage
    of a protein known as Cas9,
  112. which can be engineered
    to recognize and cut
  113. a very specific sequence of DNA.
  114. In this example,
  115. two Cas9 proteins are being used
    to excise a problematic piece of DNA.
  116. For example, a part of a gene
    that may give rise to a disease.
  117. Cellular machinery is then used
  118. to basically glue two ends
    of the DNA back together.
  119. As a molecular animator,

  120. one of my biggest challenges
    is visualizing uncertainty.
  121. All of the animations I've shown to you
    represent hypotheses,
  122. how my collaborators think
    a process works,
  123. based on the best information
    that they have.
  124. But for a lot of molecular processes,
  125. we're still really at the early stages
    of understanding things,
  126. and there's a lot to learn.
  127. The truth is
  128. that these invisible molecular worlds
    are vast and largely unexplored.
  129. To me, these molecular landscapes
  130. are just as exciting to explore
    as a natural world
  131. that's visible all around us.
  132. Thank you.

  133. (Applause)