Anonymous
Anonymous asked in Science & MathematicsBiology · 1 decade ago

Fluid Mosaic Membrane Model?

These are my notes which I had to make myself from my textbook. See, my teacher DOES NOT teach us anything, and if we ask him a question he calls us idiots. Can someone make it simple for me to understand? Test tomorrow by the way.

-The fluid-mosaic model is a description of cell membrane structure in which phospholipids form a bilayer that has a fluid consistency and is studded with protein molecules.

-Lipids do not dissolve in water, thus causing a border around the cell. The edges of the border defines and contains the fluid lipid layer.

-Biochemists and electron microscopists gave researched intently on the subject and they have concluded that the cell membrane all contains a mosaic of different components scattered throughout it.

-For example, numerous protein molecules stud the phospholipid bilayer, and the phospholipid molecules and some of the proteins can drift sideways in the bilayer. This supports the idea that the phospholipid bilayer has a fluid consistency.

Update:

I need it to be put into simpler terms. The entire thing confuses me.

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  • 1 decade ago
    Best Answer

    Perhaps the easiest way to imagine the 'fluid mosaic model' is like the surface of a swimming pool.

    The surface exists because there are things that are incompatible next to each other. In the pool it's water and air. In a cell it's polar stuff (water and things that dissolve in water) and non-polar stuff (fats, lipids, oils, and the like). For a cell, the only place something non-polar is happy inside that two-layered membrane and shielded from all that nasty water.

    Some things aren't just one or another, but have a little bit of both. That is mostly what makes up the membrane - molecules with a polar head and a long non-polar tail. Cells use this to their advantage to make large proteins also with polar and non-polar parts so they too bob in the membrane but can have access to things on one side or another of it (and sometimes on both sides).

    Like floats bobbing in a pool, things stuck in a membrane aren't necessarily in one spot of the surface or another. Cells keep things anchored when they need to by attaching them to the cytoskeleton, but more often surface proteins just drift around the membrane as they like. This kind of movement by surface proteins in membranes is what first clued scientists in to the idea that the membrane must be fluid.

    Really small stuff can often sneak through the membrane on its own. Ions and big things can't make it across without help. And here is where the surface proteins play a big role: some of them act as gates, and because proteins can be made very specific to what fits them, with gates like this a cell can have a lot of control what stays in and what goes out. It can even spend energy to create conditions that would never normally occur because of diffusion and the like.

    That's the key notes as far as I can see. Hope that helps!

  • 1 decade ago

    Ok...

    Think of it this way:

    the cell membrane is made up of two sandwiched layers of phospholipids- fats(lipids) and water repel each other - this is how the membrane keeps the watery insides of the cell inside. If you can imagine a circle with two "tails" on it - this a phospholipid - there are two layers of these all through the membrane - hopefully your book has a picture - this is hard to describe!

    Think of the cell as a beach ball - the flexible fatty layer is like the vinyl the ball is made of. The inside of the ball is where all of the organelles would be. If you can imagine if the ball was filled with water - the membrane would flex and move with the contents.

    The membrane has lots of "gates" speckled through it (think like the beach ball had lots of the blow up holes in it). These gates (the protein molecules in the phospholipid bilayer) allow larger molecules like glucose and hormones through.

    Hopefully this helps some!

  • dandy
    Lv 4
    3 years ago

    This variety says that we trust the cellular membrane is type of a fluid and prefer a mosaic. The membrane is type of a fluid because the phospholipids bypass round one yet another freely. The membrane is type of a mosaic because the proteins make a progression contained in the exterior of the membrane.

  • 1 decade ago

    Fluid-mosaic model:

    1. The phospholipids in the membrane are free to move around each other like the molecules in a liquid can move around. In this way, the membrane is like a fluid.

    2. A mosaic is a picture made of a pattern of tiles. The proteins embedded in the membrane make a pattern in the membrane. In this way, the membrane is like a mosaic.

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  • Anonymous
    1 decade ago

    What would you like to know?

    Phospholipids have a water loving side and a water hating side. The water hating side points inwards away from the water, the water loving side points outwards. This creates a bilayer.

    The lipids are not rigid and can move about.

    Proteins in the membrane can also move about.

    if you need something specific explained just ask.

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