Membrane structure and transport

Question 1

Fluid Mosaic

Answer 1

1. Fluid means the membrane is in constant motion. Phospholipids and proteins are free to move within the membrane
2. Phospholipids are held by weak hydrophobic interactions, hence can move about rapidly by diffusion in their own layers
3. Unsaturated fatty acids of phospholipids have kinks that keeps the molecules from packing together, hence, increasing membrane fluidity
4. Mosaic means that proteins are embedded within the phospholipid bilayer randomly. Proteins can be either extrinsic or intrinsic

Question 2

Differences between facilitated diffusion and osmosis

Answer 2

1. Facilitated diffusion requires channel proteins while osmosis does not
2. Facilitated diffusion involves the passive movement of polar molecules and charged ions while osmosis involves the net movement of water molecules