Inside a cell

GradualStudent wrote

If anyone really wondering what each of the cellular structures are and what they are doing I be happy to give a brief overview of the video.

That would be appreciated. I'm reading Darwin's Dangerous Idea and he briefly mentions the origin of eukaryotes and it has had my wondering about the workings and about mitochondria. I was actually thinking that the video was an explanation. So if you could augment the visuals I would dig it. And just so you know, I'm a complete layperson so you might go right over my head.

I had another thought along the same vein as the size difference between the structures in a cell and the cell's fluid.

The cells of the fluid can't be always touching each other at rest like a box filled with styrofoam packing chips because they're hot.

This heat would manifest itself as translational kinetic energy, with the fluid molecules in constant motion transfering energy between themselves and anything else they hit.

So, two questions:

1) Can I assume this translational kinetic energy is used as a motive force by cell structures that need to move from point to point? And by 'point to point' I don't mean like navigating in a sea, I mean by transfering from one molecular binding point to another, being pushed not at random but by an eddy current of sorts within the cell.

2) What is the ration of molecule to non-molecule in a human cell at 98.6 degrees farenheit?

GradualStudent wrote

Renaissanceman,

Good question. There is one thing that you have to remember cells are composed of 90%+ of water. Even the smallest of proteins in the cell is many times greater than a water molecules. So it would be more appropriate to think of the structures as being bulldozers pushing through the small plastic beads. The bulldozer will win. Also keep in mind that the container for the fluid -the cell membrane- is a fluid structure as well and thus as the water is forced out of the way the membrane can expand or rather deflect to accomidate the displacement.

Literally composed of water, or composed of a compound made mostly of water? I... keep visualizing a lubricating fluid, like a gel or slime... mostly water but with no sticky bits to cause friction. Like shoving through a room filled with platic balls covered with oil.

I'm also having trouble with the Bulldozer metaphor. Bulldozers are powerful... whereas the molecules in a cell should be more collaborative... I.E. not powering their way along with decisive force (Like a bulldozer does), but being pushed and helped like a shrimp in the tide.

Pin

I will keep the explaination as non-technical as possible (One of my strong suits). The opening is simply the inside of a blood vessel. The red shooting through the middle is actually red blood cells and the whiteish-blue blobs on the sides are white blood cells. Next it goes into a closeup of the cellular surfaces (between wbc and the blood vessel lining cell). What it is showing is the contact between recognition proteins between the two. It then moves to an extreme closeup of the "fluid mosaic" cell membrane. So you are seeing the lipids and all the associated proteins (ones that simply rest on the surface and those that are imbeded in the membrane itself). The important part of that scene is the movement contact between the two proteins which causes the release of a enzyme called a transcription factor that escentially activates the protein production process within the cell.

Then the video shows a flyin scence towards the inside of the cell. The structure that are being passed are most likely microfibral (proteins that act as the cells skeleton). What is then showed is how these structures are made, a process which is a simple addition of the exact same protein piece onto the end one after another. It then shows how these are taken apart by the use of an enzyme. Then it is on the the assembly and disassembly of a microtubule, composed of two proteins (in the video blue and green) that always line up one after the other ABABAB etc. Microtubules are for transport around the cell but the transport is external on the tube not in the tube. Which is shown in the next scene with the transport protein. I would explain the walking mechanism but that would take a lot long. Needless to say it work in a similar method to Actin and Myocin in muscles and requires ATP for the the movement. The blob being transported is a vacuole (a membrane enveloped pack of proteins, carbohydrates, etc.).

The next major scenes are simply the protein translation and production process. Messanger RNA from the nucleus are translated by ribosomes to produce a new protein. The new protein in this case is going to a mitochondrian. The next translation and protein production takes place at the golgi bodies or golgi apparatus (same thing note: big blobby structure in video). This is where proteins and everything else is packaged in a vacuole for transport. Finally what is seen is the release of a protein vacuole by merging the cellular membrane with that of the vacuole and the release of another protein which causes the wbc to squeeze between the two lining cells. Most likely this whole video is showing a wbc response to a body cell signaling an infection.

Hope thats not to complex although it may be a little long.

Renassiance

The liquid is literally water. Mind you there are ions floating around but as these are soluable they would move freely with the water. The "gel" you are thinking of does not exist at this level. I say it doesnt exist because the cause of the "gelling" is the very protein structures shown in the video especially the microfibrals, microfilaments, and microtubules among others.

You asked before if the kinetic movement of the water resulted in cell movement this is only partially true. The proteins i mentioned have connections to the cellular membrane so in order to create movement the cell builds these structure in one direction forcing the cell wall outward and breaking them down on the other side creating the whole vaccuum situation. In other words the gel is moved from one side of the cell to the other, repeat as many time as necessary to get to desired location.

As for the ratio of molecule to non-molecule; I don't really know. I would assume (which is never good) that it would be similar to water if only because cells and our bodies as a whole have a similar density. (Although I could be very wrong on this)

Although the bulldozer metaphor might be less than satisfactory, it is still apt. When cells use these structures they often have to expend ATP to do so much like diesel for the bulldozer. Also the movement of most sturctures, proteins, other molecules within the cell are conducted not with purpose as "collaboration" would imply but rather by diffusion or sheer dumb luck. This is the reason why cells must maintain large amount of free materials within the cell i.e. amino acids, sugars, ions, ATP, etc (the cellular method of hedging your bets).

Edit: Spelling and grammar

GradualStudent wrote

Pin

I will keep the explaination as non-technical as possible (One of my strong suits). The opening is simply the inside of a blood vessel. The red shooting through the middle is actually red blood cells and the whiteish-blue blobs on the sides are white blood cells. Next it goes into a closeup of the cellular surfaces (between wbc and the blood vessel lining cell). What it is showing is the contact between recognition proteins between the two. It then moves to an extreme closeup of the "fluid mosaic" cell membrane. So you are seeing the lipids and all the associated proteins (ones that simply rest on the surface and those that are imbeded in the membrane itself). The important part of that scene is the movement contact between the two proteins which causes the release of a enzyme called a transcription factor that escentially activates the protein production process within the cell.

Then the video shows a flyin scence towards the inside of the cell. The structure that are being passed are most likely microfibral (proteins that act as the cells skeleton). What is then showed is how these structures are made, a process which is a simple addition of the exact same protein piece onto the end one after another. It then shows how these are taken apart by the use of an enzyme. Then it is on the the assembly and disassembly of a microtubule, composed of two proteins (in the video blue and green) that always line up one after the other ABABAB etc. Microtubules are for transport around the cell but the transport is external on the tube not in the tube. Which is shown in the next scene with the transport protein. I would explain the walking mechanism but that would take a lot long. Needless to say it work in a similar method to Actin and Myocin in muscles and requires ATP for the the movement. The blob being transported is a vacuole (a membrane enveloped pack of proteins, carbohydrates, etc.).

The next major scenes are simply the protein translation and production process. Messanger RNA from the nucleus are translated by ribosomes to produce a new protein. The new protein in this case is going to a mitochondrian. The next translation and protein production takes place at the golgi bodies or golgi apparatus (same thing note: big blobby structure in video). This is where proteins and everything else is packaged in a vacuole for transport. Finally what is seen is the release of a protein vacuole by merging the cellular membrane with that of the vacuole and the release of another protein which causes the wbc to squeeze between the two lining cells. Most likely this whole video is showing a wbc response to a body cell signaling an infection.

Hope thats not to complex although it may be a little long.

Cool, thanks! I wouldn't say it was too long or complicated especially considering the complexity of the things you are describing. I had to look up a few things like ATP but that is a reflection of my own lack of edumacation. I think I understand it as much as I can at this point.

your welcome

I got to head out to class now and contribute (as little as possible to get a good grade) to the fascinating (very much so) but exceeding boring to read (drying paint is more fun) world of paleobiolgy papers. Ill reply to anything that needs replying to later.

Edit: spelling

GradualStudent wrote

Although the bulldozer metaphor might be less than satisfactory, it is still apt. When cells are these structure they often have to expend ATP to do so much like diesel for the bulldozer. Also the movement of most sturctures, proteins, other molecules within the cell are conducted not with purpose as "collaboration" would imply but rather by diffusion or sheer dumb luck. This is the reason why cells must maintain large amount of free materials within the cell i.e. amino acids, sugars, ions, ATP, etc (the cellular method of hedging your bets).

Yes! Exactly! I wasn't implying movement by intent, I was implying movement by sheer dumb luck, but luck with serendipity in the presence of something shoving it along in one direction, as opposed to random motion.

Hmm, good point about the water, there really isn't any 'extra space' in water at body temperature. The molecules just aren't 'sticky' and move freely, jostling their way along through the vibratory energy of heat and the movement of the other water molecules.

I need to go to college. Thinking about it, the individual molecules of water would have a shell of negative charge, and would just glide off each other like two magnets pushing their like poles against each other. Likewise, the 'space' between them is only the distance required to keep the magnetic force in balance with the average translational kinetic energy of the molecules. You need to add a LOT of heat to impart enough energy to seperate the molecules any distance... but then, why is there air?

Someday, I'll have an epiphany... and suddenly believe that I actually understand the universe. On that day, I'll also realize that I don't understand the universe at all... the rabbit hole is deep!

[Eva]

hang around, gradualstudent....you have quite a way with words....

TheAmazingPinball wrote

I'm glad I finished reading the rest of the posts before I said the same thing. Has myst always been this much of a tool or am I just noticing now because he's on my radar?

Anyway, welcome Gradual and cool video. :cheers:

Meh, he's been a butt-wad for awhile, but at least he used to pretend to be atheist. He's been pikin' to be a Mod for nigh on a year, and is one of the last possible candidates I can think of.
edit: Welcome, Grad!