The cell membrane is

Question

important for
maintaining
homeostasis, because it
controls what enters
and leaves a cell.
1. Sketch the
phospholipid bilayer of a cell membrane below and label the
polar heads and nonpolar tails.

Answer 1

To sketch the phospholipid bilayer of a cell membrane, you can follow these instructions:

1. Draw two parallel lines to represent the bilayer. The space between the two lines represents the interior of the membrane.

2. Draw the phospholipid molecules. Each molecule consists of a "head" and two "tails":

   • For the polar heads, draw small circles or ovals facing outward (towards the exterior of the cell on the top line and towards the interior of the cell on the bottom line).
   • For the nonpolar tails, draw two wavy lines extending inward from each head, pointing toward each other in the center gap.

Here’s a basic sketch guideline:

    (Head)      (Head)
     O          O
      \        /
      ~~~~~~~~
      ~~~~~~~~
      /        \
     O          O
    (Tail)    (Tail)

Labeling:

• Label the polar heads as "Polar Heads" (the O shapes).
• Label the nonpolar tails as "Nonpolar Tails" (the wavy lines).

Make sure to emphasize that the heads face the aqueous environments both inside and outside the cell, while the tails face each other, creating a hydrophobic interior. This arrangement is crucial for the membrane's function in maintaining homeostasis by regulating what enters and exits the cell.