Question

explain the fluid mosaic model
use the correct terms to complete the sentences that explain how the fluid mosaic model of a membrane works.

1. in membranes (click to select) associate to form two layers.
2. larger (click to select) float within the bilayer.
3. integral membrane proteins (click to select) in a membrane.

Explanation:

1. In the fluid mosaic model, phospholipids (lipids with a phosphate group) have a hydrophilic head and hydrophobic tails. The hydrophobic tails face inward, and hydrophilic heads face outward, associating to form a bilayer (two - layer) structure. So for the first blank, the term is "phospholipids".
2. Proteins are larger molecules compared to phospholipids in the membrane. These proteins (like peripheral and integral proteins) float within the phospholipid bilayer. So for the second blank, the term is "proteins".
3. Integral membrane proteins are embedded within the phospholipid bilayer. Some span the entire membrane (transmembrane proteins), while others are partially embedded. So for the third blank, a suitable term is "are embedded" (or other similar terms like "are inserted" depending on the context, but "are embedded" is a common description for integral membrane proteins in the fluid mosaic model).

Answer:

1. In membranes, $\boldsymbol{\text{phospholipids}}$ associate to form two layers.
2. Larger $\boldsymbol{\text{proteins}}$ float within the bilayer.
3. Integral membrane proteins $\boldsymbol{\text{are embedded}}$ in a membrane.