Amazing Science: Ten Craziest Things Cells Do

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00:00:06.17 Hello and welcome to 10 craziest things
00:00:09.06 cells do. My name is Wallace Marshall and I teach at
00:00:11.24 UCSF, the University of California, San Francisco.
00:00:14.04 In today's talk, we're going to tackle the myth that
00:00:18.28 cells are small, simple, and stupid. Why do we all
00:00:21.25 tend to think that? It arises from the idea of cell theory.
00:00:24.19 And so cell theory is built on two premises,
00:00:27.02 one is that cells are small, simple building blocks,
00:00:29.27 similar to atomictheory. And also the second part of
00:00:33.14 cell theory is that cells are separate compartments of living
00:00:36.17 matter, and that's why they're called "cels."
00:00:38.11 So typically when we learn about cells in school,
00:00:41.02 we learn some picture like this shown here, where it's
00:00:43.27 a relatively simple bag or box full of watery enzyme
00:00:47.13 with a few parts in it, but pretty simple and kind of boring.
00:00:50.17 And the general view about cells is that they're
00:00:53.20 not very exciting, they're relatively simple, like the lego
00:00:57.14 block. And the only way to build anything interesting
00:01:00.06 is to have lots and lots of cells.
00:01:02.10 It turns out, though, when you look at real cells, they're not
00:01:06.18 necessarily simple at all. They can be very complicated and
00:01:09.10 make beautiful shapes. So I've just shown here a few examples of
00:01:12.20 cells, both free living cells and also cells from the bodies of animals
00:01:16.12 and plants, in which the cells are much more complicated than
00:01:19.15 just a little bag of enzymes. No one knows where all the
00:01:22.04 shape comes from, but it makes you think that maybe cells
00:01:24.19 could do much more complicated things than just sit there
00:01:27.01 and be building blocks. So today's lecture, we're going to talk about
00:01:30.29 10 crazy things that cells can do.
00:01:33.24 One thing that cells can do that's crazy is get really big.
00:01:37.02 It's not crazy that you get big, but it's crazy how big they can
00:01:40.14 get. Here's one example, Gromia sphaerica. It's a round amoeba
00:01:45.00 that lives on the ocean floor, and a single cell can be 1.5 inches
00:01:49.02 in diameter, the size of a large grape or small ping pong ball.
00:01:53.05 And as you can see here, they're comparable in size to an
00:01:57.01 animal, here are several Gromias shown next to a shrimp.
00:02:00.02 And I love this picture, because it looks as though the cells
00:02:02.10 are actually chasing the shrimp down and trying to kill it.
00:02:04.18 They aren't really doing that, but it just gives you that impression.
00:02:07.11 But another nice thing about this image is that you see
00:02:09.22 how the cells can leave behind trails in the dirt.
00:02:12.07 And there's an ongoing controversy now in people who study
00:02:15.22 trace fossils, who want to know when did hard-bodied animals
00:02:19.05 first evolve. They've often based those arguments on seeing traces
00:02:23.01 and tracks in the dirt that have been fossilized, and it's now thought
00:02:26.19 some of those tracks could be things like Gromia that
00:02:28.27 were big enough to leave trails, even though they were just
00:02:31.05 single cells. Gromia's big, but it's not the biggest
00:02:34.06 cell we know. One really big kind of cell is Acetabularia, it's a green
00:02:38.02 algae. And this is a clump of them. Each individual cell
00:02:41.10 looks like a plant, it's got a root at the base, a stalk, and then
00:02:44.18 this flower-like cap, you see. Each single cell could be 10cm
00:02:48.22 long. You could hold these cells in your hand like little
00:02:51.13 flowers and even make a bouquet out of them.
00:02:53.05 So this is extremely large, these are among the largest
00:02:56.19 single cells we know that have just one nucleus.
00:03:00.16 If you let cells have lots of nuclei, then there's even bigger
00:03:02.28 examples. This is an example of Caulerpa, which is a multinucleate
00:03:08.15 syncytial cell. This bush-like plant here, is actually one single cell
00:03:13.16 that makes many branches and fronds and leaves, but it's all
00:03:16.08 just one cell. And it can be larger than a human being.
00:03:18.29 And just one cell. So cells can be crazily large,
00:03:22.14 so that's crazy thing number 10 that cells can do.
00:03:24.29 Some cells, though, can be extremely small. And this example
00:03:30.13 is Ostreococcus tauri, which is only about a micron in diameter
00:03:34.09 and is so small that it only has one of everything. So the entire
00:03:38.20 cytoskeleton is just one microtubule.
00:03:40.14 Number 9, cells that walk. We're used to thinking about
00:03:44.24 cells moving by crawling along a surface like an amoeba,
00:03:48.00 or we think about cells that can swim through pond water.
00:03:50.18 But cells have many other ways that they can move, for example,
00:03:53.29 this kind of cell here, Stylonychia, is a type of ciliate that's able
00:03:57.17 to walk. It walks using clusters of cilia on the bottom surface of the
00:04:01.16 cell. And as shown in the picture on the right, it can actually walk
00:04:04.14 along leaves and branches inside the pond.
00:04:07.18 So this is one remarkable way the cell can walk.
00:04:09.28 And if you didn't know better when you see these things moving,
00:04:11.21 you would think they were little insects like cockroaches,
00:04:13.29 but it's just one cell. But there are other varieties of motile
00:04:18.20 behaviors that cells can do beyond just walking. For example,
00:04:22.14 there are cells like Dileptus shown here, that are basically
00:04:25.11 vampire cells. They have a sharp little needle they can poke
00:04:28.11 into other cells and then drink their cytoplasm. There's also
00:04:32.06 cells that can open up mouths that they have, into gigantic
00:04:34.24 mouths that can swallow other cells whole. For example,
00:04:37.15 here is Didinium swallowing a Paramecium whole.
00:04:40.09 So there's a wide variety of movements that cells can do,
00:04:44.14 moving and also attacking other cells.
00:04:46.15 Number 8, cells that go left. So I've talked about weird ways that
00:04:53.18 cells can move by walking and by opening their mouths,
00:04:56.09 but even among cells that crawl the normal way, there's
00:04:59.03 very strange things that certain cells do. For example, there was a
00:05:02.14 beautiful paper by Xu et al, showing that white blood cells
00:05:06.20 tend to move left. So what they did was they looked at cells
00:05:11.09 in the absence of any chemical attractive signal, just sitting on
00:05:14.23 the dish. And they drew a line from the nucleus to the centrosome,
00:05:18.10 basically giving you an idea of the axis that the cell is oriented in,
00:05:21.27 and so they show that line in these graphs here with this red arrow.
00:05:24.27 They then added a chemoattractant everywhere in the media,
00:05:28.13 so the cell has to pick a random direction to start moving in.
00:05:31.11 And the remarkable thing, as shown by the blue dots, is that
00:05:34.05 most of the cells will move to the left of their original direction.
00:05:37.08 So these cells know left from right. How does a watery bag of
00:05:41.12 enzymes know which way is left and which way is right?
00:05:44.00 It's really not clear. The one structure in the cell that does
00:05:47.15 have a left and right handedness to it, though, is the centriole.
00:05:50.10 So as shown here, the centrosome contains a pair of
00:05:53.05 centrioles, that are basically barrel like structures made of microtubule
00:05:56.06 triplets. And those microtubule triplets have a certain handedness
00:05:59.10 as they go around the centriole. So you could imagine that this
00:06:02.16 might be a source of left or right handedness in a cell.
00:06:05.04 And in fact, in this paper, when they ablated the centriole,
00:06:08.25 they were able to eliminate the leftward bias of the motion.
00:06:11.08 So this just tells us that the ability of cells to move and the
00:06:15.08 decisions that they make while they're moving are probably
00:06:17.14 a lot more complicated and crazier than we ever would've thought.
00:06:20.11 Number 7, tunneling nanotubes. A fundamental part of cell
00:06:27.07 theory is that each cell is a totally separate entity disconnected
00:06:30.27 from all the others. That's why they were called cells in the first
00:06:33.00 place. But in fact, we know that cells are often connected
00:06:35.28 with each other. This is well known in plants, you've probably heard
00:06:38.19 about plasmodesmata, shown at the bottom. Which are tubes
00:06:41.13 connecting plant cells after they divide. But it's also true
00:06:44.24 in animal cells, so one thing that we've discovered in the past decade
00:06:47.18 is that many animal cells can be joined by very narrow
00:06:50.20 connections called tunneling nanotubes. Which allow cells
00:06:54.13 to join to each other and exchange various chemicals
00:06:57.04 and maybe even organelles. So even though they look separate,
00:07:00.08 the cells are really connected at a small enough scale.
00:07:03.10 Tunneling nanotubes are a specific case of the more general
00:07:07.16 idea that cells are not as separated from each other as one
00:07:10.03 might think. And there are many different examples that have
00:07:12.20 come to light. For example, shown on the top here is the
00:07:15.21 phenomenon of leukocyte transcellular migration. In this case,
00:07:19.05 white blood cells or leukocytes in the bloodstream want to escape
00:07:22.06 from the blood vessel and attack invading organisms in your
00:07:26.28 tissue. So they have to get through this epithelial layer, but the
00:07:30.12 epithelial cells are very tightly connected to each other. And actually,
00:07:33.06 the leukocytes cannot squeeze through them. So instead,
00:07:35.22 they just dive right through the cells. So you can have a leukocyte
00:07:38.17 crawling inside another cell, and this is happening all the time
00:07:41.27 right now in your bodies. So you can have cells inside of other
00:07:45.01 cells. You also can have cells that let go of membrane vesicles
00:07:49.01 which can then be taken up by other cells and passed from one
00:07:52.16 cell to another like a bucket brigade, and these are called
00:07:54.15 argosomes, shown here on the bottom. An even more
00:07:57.17 weird example, which I feel is weirder than argosomes,
00:08:00.22 is kleptoplasty. This is a phenomenon whereby the cells of
00:08:04.05 one organism can eat another cell and digest it and then
00:08:08.01 save the organelles from that cell and put them inside
00:08:10.08 of itself. So here we see a sea slug, the reason why the
00:08:14.00 sea slug is green is because the cells of these sea slugs
00:08:17.13 contain chloroplast that they stole from green algae that
00:08:20.26 this organism was feeding on. So that's why they call it
00:08:25.08 kleptoplasty, the stealing of plastids or organelles.
00:08:28.19 So all these examples just show that cells really are not
00:08:31.16 as disconnected as one tends to believe and they're constantly
00:08:34.13 exchanging material in ways that we're only now beginning
00:08:37.14 to understand.
00:08:40.10 Number 6, cytoplasts. What a cytoplast is, is under certain
00:08:45.01 conditions, for example, by heat shock, a piece of the cell
00:08:48.23 -- a piece of the cytoplasm will just decide to take off by itself.
00:08:51.09 And that's shown here, you have a little piece of cytoplasm
00:08:54.16 that's just crawled away from the rest of the cell. These cell
00:08:57.16 fragments can move by themselves, they leave behind the nucleus,
00:09:00.22 the centrosome, the golgi, most of the components of the cell are
00:09:03.26 left behind. But yet, this little fragment of cytoplasm is still
00:09:06.21 able to move and it can still do chemotaxis. The main reason
00:09:10.14 why researchers study these is because it allows you to ask
00:09:13.11 what behaviors can a cell do without the other organelles?
00:09:17.02 And in particular, you can show that you don't need the nucleus
00:09:20.16 or genes to do chemotaxis. So it's been very useful to rule out
00:09:25.20 transcription as an important factor in many behaviors. But on
00:09:29.08 some level, formation of cytoplasts is still a laboratory artifact.
00:09:32.16 However, it points to the ability of other cell types to naturally
00:09:36.14 fragment. The really classic example being platelets.
00:09:39.14 So platelets are structures that float in your blood that are
00:09:42.05 important for wound healing, for promoting a blood clot.
00:09:44.17 But what platelets actually are is tiny fragments of a much
00:09:48.03 larger cell called a megakaryocyte. And as shown in this
00:09:51.08 cartoon, the megakaryocyte grows and grows, sends out
00:09:54.22 long, long fibrils, which then fragment to make lots of tiny
00:09:58.03 little pieces, and those are the platelets. So this again
00:10:01.20 speaks to the exceptions to cell theory that we need to think
00:10:05.04 about. Normally, we think about the cell as being the minimal
00:10:07.27 unit of biological function. But here's an example where the
00:10:10.21 important unit of function is actually a tiny little fragment of the
00:10:13.04 cell that's been shattered and is now freely moving around
00:10:16.06 in the blood.
00:10:18.03 Number 5, cells that can sense electricity.
00:10:21.17 So now we're starting to get into the realm of the truly crazy.
00:10:24.13 So when you look at a mitotic spindle, just visually, the
00:10:28.17 microtubules of the spindle look an awful lot like the lines
00:10:31.16 of magnetic force around a bar magnet. Now there's absolutely
00:10:35.15 no similarity between these two phenomena whatsoever,
00:10:39.04 they just look similar. Nevertheless, the fact they look similar
00:10:42.04 tends to make you want to think about, could there be electric
00:10:44.20 fields doing something important in biology, in cell biology?
00:10:48.13 And in fact, this has led to a variety of proposals and inventions,
00:10:52.23 including several patents for equipment that would use
00:10:55.21 electric fields to change the behaviors themselves. It's not
00:10:59.29 entirely clear whether these would actually work. They're considered
00:11:02.27 a little bit on the fringe of what we know, but nevertheless,
00:11:06.09 there is one very clear case where electricity is affecting what
00:11:09.17 cells do. And that's the phenomenon of galvanotaxis.
00:11:13.13 So this is illustrated in this slide here, where we see
00:11:16.20 keratocytes from a fish, which are moving in the direction
00:11:19.15 of an applied electric field. And this is a well known
00:11:21.23 phenomenon, galvanotaxis. Why would cells care about
00:11:25.19 electric fields? Well, it turns out, epithelial layers like
00:11:28.24 your skin, have an electric potential across them.
00:11:32.00 So the cells in the skin are constantly pumping ions back
00:11:35.00 and forth, and if you were to punch a hole in your skin,
00:11:38.16 for example, if you get cut or wounded, that would now
00:11:41.06 produce an electric field that varies from position to position
00:11:43.16 across the skin. This then gives an electrical cue for the
00:11:47.16 keratocytes to move towards the site of the wound, so they
00:11:50.03 can fill in the hole. So galvanotaxis is not only a real
00:11:53.11 phenomenon, it's actually really important for your ability
00:11:56.02 to heal wounds.
00:11:57.28 Number 4, cells that can solve mazes.
00:12:01.05 Part of cell theory is that we think cells are relatively
00:12:05.08 stupid, because they're so simple and they need to be used
00:12:07.18 as building blocks. So therefore an individual cell probably
00:12:10.05 can't do that much. That's not necessarily true, and in fact,
00:12:13.12 we really don't know how much computation one cell can
00:12:15.29 perform. People have done various interesting experiments
00:12:19.04 to ask whether cells can do problem solving, one classic
00:12:22.16 example, is can cells solve mazes?
00:12:24.16 So here I'm showing two examples of maze solving by cells.
00:12:27.20 One is Physarum, which is a syncytial slime mold. So a single
00:12:31.28 cell will fill up a maze and it will eventually grow such that the
00:12:36.23 fibers of the cell will find the shortest path between the
00:12:40.25 entrance and exit of the maze, between two chunks of
00:12:42.29 food. So, in this sense, Physarum is able to solve the maze.
00:12:46.09 Filamentous fungi can also solve mazes, as shown on the
00:12:49.11 bottom. They can send little filaments into the maze
00:12:51.25 and those filaments make choices about which way to move
00:12:54.13 when they hit a corner or intersection. And it's been shown
00:12:57.19 that the choices that the single cell makes are better than
00:13:00.17 just random. So it is somehow solving the maze.
00:13:02.27 Cells can also solve a well-known problem in computer science
00:13:06.19 called the "traveling salesman" problem.
00:13:08.13 So the traveling salesman problem is, if you're a salesman
00:13:11.11 and you want to visit a number of cities in defined locations, how
00:13:14.18 do you decide which order to visit those cities so you minimize
00:13:17.08 the total traveling that you do? It's known from computer science
00:13:20.07 theory that many different problems can be shown to be
00:13:23.13 equivalent to traveling salesmen. So if you can solve this
00:13:25.29 problem, you can solve many problems in computer science.
00:13:27.27 Turns out that single cells can solve this problem of traveling
00:13:31.09 salesmen. Here's an example of the Physarum, and again this is
00:13:34.13 syncytial slime mold. And what the experiment done here was
00:13:37.18 researchers put chunks of food in a pattern that mimics the
00:13:40.28 location of cities and villages surrounding Tokyo. They then let a
00:13:44.23 single cell of physarum grow until it built various filaments connecting
00:13:48.01 these food sources. They then found that the pattern of these food
00:13:52.03 sources, not only is optimal, in terms of matching the traveling
00:13:56.02 salesman problem, it also very closely mimics the actual
00:13:59.23 railway map of the greater Tokyo area. Arguing that the single
00:14:03.11 cell can do the same kind of problem solving that human
00:14:06.06 engineers would do when they plan out a railway map.
00:14:09.01 So this all shows that cell are probably a lot smarter than we
00:14:12.10 think they are. And we probably are only beginning to scratch
00:14:14.19 the surface of what kind of problems they can solve.
00:14:16.18 Cells can also learn, and they can show simple types of learning.
00:14:20.23 Here's an example, where we see Stentor coeruleus, this is a
00:14:24.14 pond-dwelling ciliate that normally stretches out into the shape
00:14:27.10 of a cone. And as it's stretched out as a cone, it can filter
00:14:30.06 feed. So it's eating bacteria and algae. But while it's stretched
00:14:33.21 out, it's vulnerable to other organisms eating it. So something
00:14:36.26 touches it, it contracts down into a ball, shown here.
00:14:39.10 Once it's contracted though, now it can't feed anymore.
00:14:42.16 So the cell has to decide when something touches it,
00:14:45.03 is it really dangerous or not? How does it know it's dangerous?
00:14:48.16 It does the same way human does, by experience.
00:14:50.29 If something happens all the time, you learn that it's safe.
00:14:53.14 For example, if you live near a railway track, you don't get scared
00:14:55.25 when the train goes by anymore. So that's habituation.
00:14:58.11 It's a common form of learning that all animals do.
00:15:00.13 And actually, the Nobel prize was awarded to Eric Kandel for studying
00:15:03.03 this exact kind of learning in Aplysia, the sea slug.
00:15:06.05 As shown in the graph here, if you tap Stentor cells
00:15:10.02 again and again and again, they will gradually learn to
00:15:12.20 ignore the tap, showing that they do in fact do habituation.
00:15:15.11 So this shows the cells not only can solve problems like mazes,
00:15:18.24 they can also learn like animals. It really raises the question,
00:15:21.21 how much thinking can a cell actually do?
00:15:24.25 Number 3, cells that can see.
00:15:29.22 In a series of controversial papers, Gunter Albrecht-Buehler
00:15:32.16 argued that cells possess some kind of eye that allows them
00:15:35.20 to detect information at a distance. Several experiments he did
00:15:39.14 showed that cells can move toward infrared light sources,
00:15:42.08 and perhaps more controversially, that cells can align to each
00:15:46.08 other, even if they're on opposite sides of the glass coverslip.
00:15:49.05 Now this is not something that everyone necessarily
00:15:52.03 thinks is true, I'm not aware of any careful attempts to reproduce
00:15:55.12 this by anyone. Because I think most people think this is just
00:15:57.26 so unusual, unexpected, and crazy. But doesn't mean it's not true,
00:16:01.15 however. And in fact, there are clear cases where cells are able
00:16:04.29 to sense and use light, and effectively see. This is quite common
00:16:09.17 in algae, so Chlamydomonas is a green alga that swims with two
00:16:12.19 flagella, as shown here. Has a eyespot that can detect light
00:16:15.19 coming from particular directions. So as it swims, it's scanning
00:16:18.27 for light and it can go directly toward the light source very quickly.
00:16:22.05 This is just a very simple eye spot, it's just a patch of photoreceptors.
00:16:25.19 But there are more complex eyes, for example, dinoflagellates
00:16:28.17 form a reflecting lens that actually focuses light outside of the
00:16:32.22 cell body, right onto the interior of its flagellum, where the
00:16:35.12 photoreceptor molecules are located. Other dinoflagellates
00:16:38.24 like Warnowia, form actually a clear lens just like the human
00:16:43.00 eye has, and it uses the lens to focus light onto its
00:16:46.14 photoreceptors. So cells definitely do have eyes, what we don't
00:16:50.12 know yet is how much information they get from that
00:16:52.28 light, whether it's just the intensity of the light or just the spatial
00:16:55.28 information. That's still, I think, an open question.
00:16:58.16 Number 2, exploding cells.
00:17:03.08 There's nothing more extreme that you can do than to explode.
00:17:06.05 And there are cells that do just that. Here's an example,
00:17:10.03 this is Magnaporthe grisea, also known as the rice blast fungus.
00:17:13.23 It causes the disease that destroys rice crops.
00:17:16.17 And the way it infects a plant cell is, it has to get through
00:17:19.27 the tough wall of the plant cell. How does it do that?
00:17:22.19 It does it by forming this structure here called the appressorium,
00:17:25.10 and shown in high-mag down here. Where it's a protrusion of the
00:17:28.12 cell that becomes surrounded by a thick cell wall and it fills up
00:17:32.03 with melanin, creating a very strong osmotic pressure.
00:17:35.10 Actually, the pressure that builds up inside this thing is 10 Mpa,
00:17:38.26 the same pressure of a bullet. When the cell builds the appressorium
00:17:43.24 on top of the plant surface, it then suddenly ruptures at just
00:17:46.28 one point, releasing this massive pressure into a tiny little
00:17:50.06 spot on the plant cell, punching a hole into it. Like shooting
00:17:53.02 it with a bullet from a gun. So by exploding, this cell produces
00:17:56.20 a breach in the defenses of the plant and allows the fungus
00:17:59.14 to invade that plant. This is a relatively extreme example.
00:18:03.20 Most cells do not explode in this dramatic manner, but many
00:18:07.20 cells do actually take advantage of hydrostatic pressure
00:18:10.28 in order to move. And this is a phenomenon called blebbing.
00:18:14.14 So as shown here, cells will sometimes have the cell membrane
00:18:17.18 let go from the actin cortex, and then hydrostatic pressure will then
00:18:21.19 push out this bleb of the membrane, which can then
00:18:24.02 fill in with more actin. And that allows the cell to then move a little
00:18:26.27 bit forward. And cells can move forward progressively
00:18:29.23 by these blebbing events, and there are beautiful theories showing
00:18:32.14 how the hydrostatic pressure is enough to provide the force
00:18:35.00 for this motion. So this shows that even very extreme phenomenon
00:18:39.21 like cells exploding, often point to very fundamental and universal
00:18:43.22 cellular behaviors that most cells actually do.
00:18:46.29 Number 1, the craziest thing that I'm aware of is cells
00:18:50.21 that can eat your brain and control your mind.
00:18:53.06 The cells we're talking about are Toxoplasma, shown here in
00:18:56.23 this image, they have this conoid organ that they can use
00:19:00.15 to puncture and move inside of other cells. And if they get into
00:19:04.02 your brain, they will actually eat holes in your brain. Now
00:19:07.04 it turns out, this isn't really that bad for you. Many people,
00:19:09.23 many of us, have toxoplasmosis. We have these organisms
00:19:13.02 that have eaten holes in our brain, you can get it from your
00:19:15.09 cats if you're pregnant or immunocompromised. Or if you
00:19:18.02 eat a lot of raw meat like carpaccio or beef tartare,
00:19:20.19 you can get toxoplasma infections. It doesn't cause really
00:19:23.28 overt symptoms, it doesn't kill you, but interestingly enough,
00:19:27.15 a researcher called Jaroslav Flegr, shown here, has combined
00:19:31.02 personality tests with immunoassays for toxoplasma infection.
00:19:35.26 And what he finds is that individuals who have had toxoplasma
00:19:39.26 infect their brain, tend to have a variety of personality
00:19:43.06 traits. So for men, it tends to correlate with dressing sloppily.
00:19:46.10 For women, it tends to correlate with dressing overly neatly.
00:19:49.03 For both men and women, it tends to correlate with suicide,
00:19:51.26 reckless driving, and introverted personalities. So this is a case
00:19:56.05 where a single cell is somehow able to get into our brains and not just
00:20:00.02 eat random holes, but somehow actually control the way
00:20:03.06 our mind works. And if that's not crazy, I don't know what is.
00:20:06.24 So I hope you've enjoyed today's lecture. I hope it shows you
00:20:10.11 that cells are not as simple as we think they are. They're
00:20:12.25 incredibly complex, they can do crazy things, and I believe
00:20:15.28 we've only scratched the surface of what cells are capable of.
00:20:18.13 Thank you.

This Talk

Speaker: Wallace Marshall

Audience:

General Public
Educators of H. School / Intro Undergrad
Student
Educators of Adv. Undergrad / Grad
Researcher
Educators

Recorded: November 2015

Talk Overview

Dr. Wallace Marshall shares few amazing science stories. Marshall refutes the commonly held idea that cells are just bags of watery enzymes. He runs through his “Top 10 List” of unexpected and amazing science stories about things that individual cells can do. These include growing to be huge, navigating mazes, and performing feats that seem to belong in science fiction.

Speaker Bio

Wallace Marshall

Wallace Marshall received his BE in Electrical Engineering and his BS in Biochemistry from SUNY Stony Brook and his PhD in Biochemistry from the University of California, San Francisco. He was a post-doctoral fellow at Yale University. Currently, Marshall is a Professor of Biochemistry and Biophysics at UCSF. His lab is interested in the… Continue Reading