Question

question ①
the fluid mosaic model is ultimately the best depiction of the cell membrane because ______.

answer

• it shows the membrane as a sandwich, with lipid on the outside and protein in the middle
• it shows the membrane as being made of mostly carbohydrates, with few lipids and proteins
• it shows the membrane as having a hydrophilic layer on the outside and a hydrophobic layer on the inside
• it shows that the phospholipids and proteins within the layers are able to move
• it proposes that a layer of protein coats the outside of the membrane
• i dont know yet

Explanation:

The fluid mosaic model of the cell membrane emphasizes the fluidity of the membrane, where phospholipids and proteins can move within the bilayer. Let's analyze each option:

• Option 1: The fluid mosaic model doesn't show lipids on the outside and protein in the middle; the lipid bilayer has proteins embedded or associated, so this is incorrect.
• Option 2: Cell membranes are mainly lipids (phospholipids) and proteins, with carbohydrates as a minor component, so this is incorrect.
• Option 3: The phospholipid bilayer has a hydrophilic (not hydrophobic) layer on the outside (due to phosphate heads) and hydrophobic tails inside, so this is incorrect.
• Option 4: The fluid mosaic model shows that phospholipids (in the bilayer) and proteins within the layers are able to move (lateral movement, etc.), which is a key feature of the model. This matches the correct understanding.
• Option 5: The fluid mosaic model doesn't propose a protein layer covering the outside; it has proteins embedded or spanning the lipid bilayer, so this is incorrect.

Answer:

The fourth option (It shows that the phospholipids and proteins within the layers are able to move)