Why don't lipid bilayers do this instead?
>>16816598they already do that, don't they?
i know next to nothing about science but i doubt this thread will get an answer from someone who does>Why don't lipid bilayers do this instead?apparently sometimes they do, look up tail interdigitation, picrelsome googling says that there are a bunch of factors that determine whether the tails of a membrane will interdigitate or not like pressure/temperature/tail length etc, but the reason why organisms don't have interdigitated membranes is because it increases their fluidity and ion conductance, which i guess would be disadvantageous for maintaining homeostasis
>>16816598"Instead" of what? Not doing "that". They do do that already doh. It's called a "Phospholipid Bi-layer".
>>16816797tard
>>16816598Chemical Biologist here. Good question. The polar heads don't take up as much space as in the typical cartoon representation. If the lipids were arranged as drawn it would leave gaps between the polar heads.
>>16816598Don't know for sure, but consider a soap bubble, in how the surface tension causes the shape to always be tight and round. If for every external lipid's hydrophilic end is separated from each other by the internal lipid's hydrophobic tails, that's not really minimized tension. The external water pulls on the external lipid's hydrophobic ends, so all your external red balls in the pic are being pulled out and tightened together. The same can be said for the internal lipids and the internal water. So my guess is that the water outside is pulling the outside lipids outward and together, while the water inside is pulling the inside lipids inward and together. I'm seeing it as more like two magnets tugging on opposite ends of the bilayer, making both layers taut.
>>16816905As an example, imagine gathering a large faggot of pencils, half of which are upside down and mixed in the bundle. Notice that holding them all makes a very wide circle in your hands. Then imagine that instead the rightside up and upside down pens were pulled apart and gathered like the lipid bilayer, and notice that when holding them all, the circle is much narrower, and the heads of the pens are all closer together
>>16816598they do. depens on concentration and other conditions
>>16817005when an amphiphile is in water by itself does it fly around like a jet since its being repulsed and attracted in one direction?
>>16817866all particles in a fluid are sorta moving around like a jet, but my guess here would be that the head will tend to be on the side of the direction of motion yeah, but I doubt it affects something like average speed
>>16816598Phospholipid bilayer structure is more due to electrostatic interaction than pressure under normal circumstances. Think of em like a bunch of little "magnets", with the "magnet poles" being the head and the ENDS of the tails."Push" a little more (ex: higher delta p) and the lipids you depicted will actually decouple/form a channel. This is how the membrane "zipper" proteins (SNAP/SNARE or viral spikes) work, more or lessAlso, in practice, cell membranes are almost never empty. Tons of proteins span one or both sides, as do certain molecules (ex: ethanol and early anesthetics), if only temporarily (uS). In fact, the pressure within a bilayer membrane can be measurable increased compared to the environment (hypothesized how general anesthetics work, by "jamming" recepters/pores shut) and still remain intact due to said electrostatic effects.
>>16816633>based "knows nothing but is curious about everything honest and passionate learner on a journey"-anon senpai :3
>>16816598because that would just be a layer and not a bi-layer
