Living Environment - Why Do Phospholipids Form a Double Layer?

Michael Anazco                                                 Ms. Gappelberg (period 7)

Living Environment                                                        October 24, 2017        

Textbook Cell Membrane

Read Pages 77-80 and do the formative assessment questions 1 & 2 on p.80.                 

Formative Assessment

1. Why do phospholipids form a double layer?

Phospholipids form a double layer to intersperses with a variety of other molecules.

Also, because the heads are polar molecules  (form hydrogen bonds ) with water molecules found outside the cell and in the cytoplasm and they arrange on the outer layers of the cell membrane. In contrast the tails are nonpolar and (cannot form hydrogen bonds)  are found in between the polar heads in the middle of the cell membrane. The tails bond to each other (face each other).

      2.    Explain how membrane receptors transmit messages across the cell membrane.

Membrane receptors transmit messages across the cell membrane by detecting a cell and then taking action in response. The cell receptors recognizes and binds to only certain molecules to ensure only the right molecules go in inside the cell and to keep the membrane balanced. The receptor binds to a signal molecule outside the cell and changes it shape completely (even the parts inside the cell). The molecules inside the cell start to a complicated chain inside the cell to tell the cell how to act and what to do.

...