Pharyngula

Frontiers in cell biology

Alex Palazzo is talking about open questions in cell biology — in this case, control of organelle shape. Any of us who have poked around in cells know that it is not an amorphous blob of goo, but has characteristic, recognizable elements that we can see from cell to cell. What confers these stereotypic intracellular morphologies on organelles, and what are the functional consequences, if any?

(There are no jebons in there, so you don’t get to use those in your answer.)

Comments

  1. #1 kid bitzer
    May 30, 2008

    but…but…

    jebons are everywhere!

    the bible tells me so!

  2. #2 Inoculated Mind
    May 30, 2008

    Jebonics. Theological and multilingual.

  3. #3 Bishop Pontoppodan
    May 30, 2008

    Think about surface area – the more membrane an organelle has, the more/less efficient certain processes are.

    Think about organelle contacts. Mitochondrial membranes may need to be close to certain portions of the endoplasmic reticulum (ER) in order to exchange molecules.

    Think about the movement of vesicles between different compartments. The Golgi is constantly losing and gaining membrane vessicles which pinch off and fuse with each Golgi stack. These vessicles travel between the Golgi and other organelles such as the ER and the endosomes. All this vesicle exchange is dictated in large part by organelle morphology and distribution.

    Think about transport. It may be helpful that an organelle is a rod in order for it to be translocated up and down neuronal projections.

    And think about other functions. For example, the nucleus shape may influence the spatial arrangement of chromosomes and thus affect gene expression. Many cells have bizarre looking nuclei, and almost nothing is know as to how the nuclear shape is altered and how this contributes to proper cellular function .

    Sounds to me like there was an awful lot of THINKING that was necessary before these highly organized structures and processes emerged as functional systems.

    Anyone who believes that these organelles emerged by any combination of random processes absent intelligent input is either in complete denial, or worse, brain dead.

  4. #4 Glen Davidson
    May 30, 2008

    (There are no jebons in there, so you don’t get to use those in your answer.)

    In Louisiana you might get to, soon.

    Science by fiat. That’ll make science and religion (fully) compatible.

    Glen Davidson
    http://tinyurl.com/2kxyc7

  5. #5 Bishop Pontoppodan
    May 30, 2008

    “Think about surface area – the more membrane an organelle has, the more or less efficient certain processes are.

    Think about organelle contacts. Mitochondrial membranes may need to be close to certain portions of the endoplasmic reticulum (ER) in order to exchange molecules.

    Think about the movement of vesicles between different compartments. The Golgi is constantly losing and gaining membrane vesicles which pinch off and fuse with each Golgi stack. These vessicles travel between the Golgi and other organelles such as the ER and the endosomes. All this vesicle exchange is dictated in large part by organelle morphology and distribution.

    Think about transport. It may be helpful that an organelle is a rod in order for it to be translocated up and down neuronal projections.

    And think about other functions. For example, the nucleus shape may influence the spatial arrangement of chromosomes and thus affect gene expression. Many cells have bizarre looking nuclei, and almost nothing is know as to how the nuclear shape is altered and how this contributes to proper cellular function”.

    ———————————————————-

    Sounds to me like there was an awful lot of THINKING that was necessary before these highly organized structures and processes emerged as functional systems.

    Anyone who believes that these organelles emerged by any combination of random processes absent intelligent input is either in complete denial, or worse, brain dead.

  6. #6 Autumn
    May 30, 2008

    Bishop,
    When they told you that Jeebus is the answer, they failed to specify that it is the wrong answer.

  7. #7 Patricia C.
    May 30, 2008

    Let me THINK about it…oh, gawd did it! Yep, you’re right, brain dead.

  8. #8 Barklikeadog
    May 30, 2008

    Yes Bishop, me is brain dead too. OOOOHHHH it hurtz.

  9. #9 Brownian, OM
    May 30, 2008

    Believe whatever the fuck you want to Bishop, just leave the rest of us the fuck alone.

  10. #10 sublunary
    May 30, 2008

    Wow, there’s a question I never would have though to ask. I

    Those pictures of different patterned mitochondria from different types of cells are fascinating. That’s something my college bio classes glossed right over.

    I’d like to have something informative to add, but all I can add is wow. I wish I were in a position to actually investigate this.

  11. #11 kid bitzer
    May 30, 2008

    think about how unlikely it was that this *very* sequence of numbers would come up when i rolled ten dice.

    sounds to me like there must have been a lot of thinking that went into arranging those dice so that just those sides would be up!

    more thinking than went into the bishop’s homily, anyhow.

  12. #12 Entgegen
    May 30, 2008

    LAMININ!!!!

  13. #13 Gary
    May 30, 2008

    Bishop:
    Intelligent design isn’t necessary to explain the existence of these organelles. Evolution is a process which often leads to very efficient but often very unusual structures. This isn’t just a matter of historical hypotheses about how structures came to be, it has real-life applications. For example, NASA used genetic algorithms to design antenna that are really weird looking but smaller and more effective than anything that could be designed by engineers working as they conventionally do. The structures they came up with are very close to the ideal solutions for the tasks for which they were needed. We see the same outcome in cells, where very efficient systems are produced through the selection of mutations.

    http://ti.arc.nasa.gov/projects/esg/research/antenna.htm

  14. #14 Ryan F Stello
    May 30, 2008

    Bishop,

    Did it really take you six minutes to decide whether or not to add a hashed line to the exact same comment you had before?

  15. #15 Glen Davidson
    May 30, 2008

    Sounds to me like there was an awful lot of THINKING that was necessary before these highly organized structures and processes emerged as functional systems.

    Oh yeah, it always takes a lot of thinking to make everything look cobbled together out of inherited and slowly modified parts.

    You know, like children, they look like they required as much thinking to produce as a good fuck does.

    Or indeed, there is little reason for sex other than to evolve these things that “take a lot of thinking.” I have yet to hear any of you dolts come up with a reason for sexual reproduction under the “design scenario”, while sexual reproduction makes trivial Behe’s latest objections about “simultaneous mutations”, at least in anything like P. falciparum, his archetypal example.

    Glen Davidson
    http://tinyurl.com/2kxyc7

  16. #16 Ryan F Stello
    May 30, 2008

    Bishop,

    Scratch #14. I see that you also added two quote marks, corrected one misspelling (but somehow missed all the others) and inserted one word.

    Must have been a big effort for you, after all.

  17. #17 LARA
    May 30, 2008

    Surface tension, Chick tracts, noodley appendages and structural proteins such as clathrin are all thought to affect the structure and function of the organelles regardless of jebon concentration in the cytosol. Of course all the Chick tracts are sorted by the Golgi to head into the lysozymes for impending destruction and surface tension and noodley appendages are just imaginary at the intracellular level. Structurallly these things are important because Jesus loves the Endoplasmic Reticulum just the way it is, studded with fluffy ribosomal sheep shaped protein factories or not. Or maybe just because shape may effect organelle transport, speed of internal chemical reactions due to surface area and other factors such as the availability of blessed holy water as a limiting factor in cytosolic reactions.

  18. #18 Barklikeadog
    May 30, 2008

    Isn’t someone like the Bishop always fun to have around? You get to kick his ass and tell the ID crowd what morons they are. Other than mixing genes, can’t think of much that’s more fun right now that I can actually do. I don’t get out much do I?

  19. #19 Patricia C.
    May 30, 2008

    Gawd demmit Glen D – there went a perfectly good mouthful of sangria all over my screen!

  20. #20 Ryan F Stello
    May 30, 2008

    I know it’s early, but I’d like to declare LARA for thread-win!

  21. #21 Jens
    May 30, 2008

    LARA @17

    Classic, absolutely classic!!

    Surface tension, Chick tracts, noodley appendages and structural proteins such as clathrin are all thought to affect the structure and function of the organelles regardless of jebon concentration in the cytosol.

  22. #22 Jens
    May 30, 2008

    I call POE on the Bishop. His profile links to http://barakobama.com

    Are you joshing us or are you a creationist with a sense of humor.

  23. #23 Jack
    May 30, 2008

    Sounds to me like there was an awful lot of THINKING that was necessary before these highly organized structures and processes emerged as functional systems.

    Sounds to me that there is an awful lot of THINKING required to understand them. Drawing the conclusion that just because they are challenging to understand, it is therefore impossible that they exist without God’s direct intervention is bad logic.

    Kid bitzer, I like the dice analogy.

  24. #24 Jens
    May 30, 2008

    Oops, add a “c” after the “a” and before the “k” in that address.

    Jens

  25. #25 Tom
    May 30, 2008

    What would have the comments on this post been like if the Bishop hadn’t blathered. #15 and #17 wouldn’t have happened and there would only be a primordial soup of molecules sitting here. But the Bishop provided the spark of commentary… is it intelligent design by the Bishop or the catalyst for the evolution of comments?

    Gawd, I don’t know. But looking forward to what comes.

  26. #26 Rey Fox
    May 30, 2008

    Should have made this post longer, PZ, and with more science-y jargon. I’ve noticed that the creationists tend to stay away from those posts.

  27. #27 Mikkle
    May 30, 2008

    LARA,
    If the ubiquitinated Chick tracts are transported for degradation- wouldn’t it be to the liesosome, rather than lysosome?

  28. #28 mjfgates
    May 30, 2008

    God created Man specifically to figure out how cellular biology actually works, so that Man can tell God how to create living things. It’s our holy purpose.

  29. #29 DLC
    May 30, 2008

    I’m not even sure what a Jebon is.
    However, generally speaking, the engineer in me wants to say that form follows function. More efficient forms would be replicated more often, and so eventually replace the less efficient ones. But then, I’m no molecular biologist.

  30. #30 Torbjörn Larsson, OM
    May 30, 2008

    Regular patterns, I didn’t expect that. Cool!

    jebons are everywhere!
    the bible tells me so!

    Ev’ry jebon is sacred.
    Ev’ry jebon is great.
    If jebons are wasted,
    God gets quite irate.

    Ev’ry jebon is wanted.
    Ev’ry jebon is good.
    Ev’ry jebon is needed
    In cellular brood.

  31. #31 Interrobang
    May 30, 2008

    And Mikkle demonstrates the existence of a transpunson for the Pharyngulite Lab! Which makes me wonder — if cells don’t conjugate, do they decline?

  32. #32 Patricia C.
    May 30, 2008

    Now just hold on there #17 LARA – if you are going to propose that Jesus loves the endoplastic rectum, studded with fluffy sheep, you will have to cite the book and verse, other wise you’re just being an elitist science spouter… ;)

  33. #33 Torbjörn Larsson, OM
    May 30, 2008

    Jebons. [I hope, the gif's are broken on this backup pc I'm trying to get working.]

  34. #34 SC
    May 30, 2008

    You know, like children, they look like they required as much thinking to produce as a good fuck does.

    Well, if you’re not putting any thought into it, it’s probably only good for you ;).

  35. #35 Steve Zara
    May 30, 2008

    There is a factor that I couldn’t see mentioned that could be of great importance. Electrostatic attraction. Decades ago, people were looking for proteins that controlled the internal structures of chloroplasts. They couldn’t find any, and it turned out that there didn’t need to be any. The basic tendency of membranes is to want to stack together (due to van der Waals forces). This stacking can be prevented by having electric charges on the membranes. Control the lateral distribution of these charges, or screen the effects of the charges with very dilute solutions of ions and you can get all kinds of shapes. I did postdoctoral research into this in the mid and late 80s. Things have probably changed since then, but that work at least showed that always looking for specific proteins and covalently bonded structures to explain the shapes of organelles could be missing much simpler explanations.

  36. #36 David Marjanovi?, OM
    May 30, 2008

    Sounds to me like there was an awful lot of THINKING that was necessary before these highly organized structures and processes emerged as functional systems.

    Anyone who believes that these organelles emerged by any combination of random processes absent intelligent input is either in complete denial, or worse, brain dead.

    Ah, a selection denier.

    And learn to spell Pontoppidan.

  37. #37 David Marjanovi?, OM
    May 30, 2008

    Oops, forgot to close the blockquote tag. But the p tags worked just fine, so it doesn’t matter… :-)

  38. #38 Nick Gotts
    May 30, 2008

    Decades ago, people were looking for proteins that controlled the internal structures of chloroplasts. They couldn’t find any, and it turned out that there didn’t need to be any. The basic tendency of membranes is to want to stack together (due to van der Waals forces). – Steve Zara

    Sounds like something D’arcy Wentworth Thompson would have appreciated!

  39. #39 Steve Zara
    May 30, 2008

    Anyone who believes that these organelles emerged by any combination of random processes absent intelligent input is either in complete denial, or worse, brain dead.

    The postdoctoral research I did in the 80s showed that you can get most of the way to the kind of complex structures seen in some organelles through completely random processes. Lipids will naturally form all kinds of regular structures all by themselves.

  40. #40 Tim
    May 30, 2008

    Form follows function elegantly enough to look like design to the casual observer.

  41. #41 DLC
    May 31, 2008

    @40: Tim, sometimes even to the non-casual observer.
    Especially when said observer has a religious or political (or religio-political) axe to grind.

  42. #42 Arnosium Upinarum
    May 31, 2008

    Bishop:

    How confident you are in your “thinking” and estimation of what constitutes “denial”.

    Allow me to introduce to you the concept of Self-Organizing Systems.

    Ever notice any of that gigantic body of work?

    Here, let me help you get started:

    http://en.wikipedia.org/wiki/Self-organization

    http://en.wikipedia.org/wiki/Molecular_self-assembly

    Follow the links and the many MANY references. Yes, it will take longer to study and understand the idea than it takes to say something like, “OBVIOUSLY, THINKING MUST BE INVOLVED”. There’s a LOT of great work on this real and ubiquitous phenomenon. It’s everywhere.

    Yes, believe it or not, it happens just as surely as a raindrop splash “momentarily” produces a beautiful little organized pattern in the shape of a crown…whose “function” (if you must have one) is to collapse into a pattern of concentric waves expressed on the surface of a pool (D’oh! Another orderly pattern. Sheesh).

    But that lovely little crown actually lasts for an astonishingly LONG time if you happen to be counting in, say, Planck time units: by that measured perspective that ordered structure lasts more than 40 billion trillion times longer than the current age of the universe measured in units of an eyeblink (say, roughly, 1/100 second, which is also about the same as the lifespan of a crown-shaped splash). Understand: a splash or the blink of an eye is to the age of the universe as over 40 billion trillion Planck Time Units are to that splash or eyeblink. Compared to the stability (or lifespan) of many sub-atomic particles, that’s pretty darned stable.

    Guess what? Nature really doesn’t much give a hoot what seems obvious to you or anybody else. Perhaps, your charge of who is in denial or brain-dead has been somewhat misdirected? Is it at least barely possible that THAT is a possibility? Or does that possibility require too much extra “THINKING” on your part to bother with? You know, when it’s so much easier to make an assertion based on nothing more than a decision to ignore real evidence, and completely misunderstand what concepts like “random” and “order” actually mean within the context of a thermodynamic system? When it’s so much easier to wave your magic wand (or, rather, wag your magic tongue) and declare it’s the work of some “intelligent design”?

    There, done. It’s been proclaimed. Nobody needs to investigate the “mystery” any further. It’s solved. Now, wasn’t that easy? That ain’t science, bub. It’s just an opinion supported by ignorance.

    Please excuse me if I forego genuflecting before Thee as I take my leave. M’Lord. Sire.

  43. #43 David Marjanovi?, OM
    May 31, 2008

    Tim, why does the very common eukaryotic protein ?-tubulin, one of the two bulk components of microtubules and thus of the cytoskeleton, have an inbuilt GTP molecule that just sits there and does nothing, yet still costs energy to make?

    Because ?- and ?-tubulin are the result of a gene duplication event with subsequent mutation. ?-tubulin also has a GTP, but that one does something — it is converted to GDP to destroy the microtubule, and then the GDP is exchanged for GTP again. Bacteria (including chloroplasts and the mitochondria of some organisms) and archaea have not undergone this duplication and retain a single protein called FtsZ.

    Casual observers need to look closer.

  44. #44 Bishop Pontoppodan
    May 31, 2008

    Scratch #14. I see that you also added two quote marks, corrected one misspelling (but somehow missed all the others) and inserted one word.

    Must have been a big effort for you, after all.

    a few comments:

    1. The “Bishop” is an agnostic.

    2. “Pontoppodan” is how Melville spells it in “Moby Dick”

    “There seems some ground to imagine that the great Kraken of Bishop Pontoppodan may ultimately resolve itself into Squid. The manner in which the Bishop describes it, as alternately rising and sinking, with some other particulars he narrates, in all this the two correspond. But much abatement is necessary with respect to the incredible bulk he assigns it.”

    3. The corrections were made because I couldn’t get the whole quote that I was responding to to be boldface.

    4. The “Bishop” is an ardent supporter of Barack Obama and is very happy to live long enough to see an african-american President

  45. #45 Bishop Pontoppodan
    May 31, 2008

    Allow me to introduce to you the concept of Self-Organizing Systems.

    Ever notice any of that gigantic body of work?

    The “Bishop” has been studying self-organizing systems for at least 10 years. You must revisit your definition of “organization”.

    These organelles are unevolvable for one simple reason. Living systems are made up of structures and processes integrated in such a way that they not only support each other, but they contribute to the overall function of the living system. This type of organization, in which means are adapted to ends and multiple structures and processes perform multiple functions, all of which contribute to the overall functioning of the organism are unattainable by any kind of random process or chance occurrence. It requires insight and insight means intelligence. There’s simply no way to get around that basic point.

  46. #46 Owlmirror
    May 31, 2008

    The “Bishop” has been studying self-organizing systems for at least 10 years.

    The “Bishop” is almost certainly Charlie Wagner, who has been busily posting for quite a few years now on various fora to tell cellular biologists, biochemists, evolutionary biologists, geneticists, developmental biologists and even, for that matter, cosmologists, that they are ALL DOIN IT WRONG.

    He’s the perfect example that one does not need to be right-wing or religious to be a science kook.

  47. #47 Steve Zara
    May 31, 2008

    The “Bishop” has been studying self-organizing systems for at least 10 years. You must revisit your definition of “organization”.

    The “Steve” has been studying such systems since my Ph.D. in the mid 80s. It has been a disconcertingly long time.

    The internal structures of organelles may well need to be refined by proteins, but you get complex structures “for free” under the right conditions. The links to self-assembly and self-organisation are appropriate. We see such complexity even in non-biological systems.

  48. #48 Tim
    May 31, 2008

    David, how could you read my earlier comment as pro ID? Organelles are as they are because their constituent molecules and the function they serve require it. At least that’s my layman’s understanding of it, which may be sufficient for someone who’s not involved in the life sciences professionally or academically.

  49. #49 Autumn
    June 1, 2008

    Bishop, you are working backwards.
    The existence of these organelles is fascinating, but it is not so unexpected given what was present to work with.

    Don’t try to work backward to find out whether something is amazing, instead try to imagine the prior state, and ask what could happen to it.
    Suddenly things that were inconcievable become rather mundane.