Question

Eric made a physical model of a cell membrane by putting one zip-top plastic bag inside another. He punched some straws through the plastic so that they led from outside the outer bag to the inside of the inner bag.

Which of the following features of a cell membrane can be seen using Eric's physical model?

Proteins and other molecules can move around within the cell membrane.
A cell membrane is made of two layers.
Some molecules can pass directly through the cell membrane.
Pores and proteins in the cell membrane allow passage through it.

Answer 1

Pores and proteins in the cell membrane allow passage through it.

A cell membrane is made of two layers.

Answer 2

A cell membrane is made of two layers.

The cell membrane is composed by a phospholipid bilayer where the interior side is hydrophobic and non-polar, while the outside is hydrophilic and polar

Pores and proteins in the cell membrane allow passage through it.

The pores and proteins in the cell membrane have several functions such as, for example, cell signaling (proteins) and selective transport (pores)