Respuesta :
Answer:
- In water, phospholipids spontaneously arrange into a bilayer
- Steroids in cell membranes allow the membrane to be more fluid
- Phospholipid bilayers surround all eukaryotic cells
- Both plant and animal cell membranes are considered fluid mosaics
Explanation:
All living things (i.e.. both eukaryotic and eukaryotic organisms) are composed of cells, and all cells have cell membranes. In an aqueous environment, phospholipids spontaneously form bilayers: hydrophilic heads of phospholipids face the water environment at the surface of the bilayer, while hydrophobic fatty acid chains are shielded from the water in the interior. Steroids are lipids that intercalate into the bilayer of the cell plasma membrane, reducing the fluidity of the membrane. Integral membrane proteins may have different biological roles. For example, permeases are integral membrane proteins that facilitate the diffusion of certain molecules (e.g., glucose) across the cell membrane by passive transport. Both plant and animal cell membranes are considered fluid mosaics where different types of molecules (e.g., phospholipids, cholesterol, proteins, etc) are constantly moving across the membrane.