Bio Tool #7 · Membrane · SOL Module 2 & DE Bio 101 Unit 5
The membrane around your cells is not one thing. It is four macromolecule classes set into one thin sheet: lipids make the sheet, proteins do the work, carbohydrates label the outside, and nucleic acids decide what goes into it. Explore each part, then check yourself.
The colours are the ones used on the class board for carbohydrates, lipids, proteins and nucleic acids, so a tap here and a diagram in class point at the same thing. Nothing is submitted and no score leaves this iPad.
Outside the cell is on top, the cytoplasm is underneath, and the sheet runs between them. Tap any part of it to see what it is and what it does. Tap a class to see how much of the sheet that one class makes.
Showing all four classes together: the mosaic.
Tap any part of the membrane, or one of the parts listed above, to see what it is and what it does.
Eight questions on the ideas this unit makes hardest: moving things against a gradient, passive against active, what water does, what "mosaic" means, and how cells seal to each other. Each answer comes with the reasoning, right or wrong. About six minutes.
Draw the bilayer and set one piece of each of the four classes into it, each in its class colour: a phospholipid, a protein, a sugar chain on the outside, and label where the DNA instructions came from. Then draw a pump moving something uphill with an arrow for the energy it spends.
Then leave it. Run the check again another day, rested, and see which of these has moved.