Question

the cell membrane: key information
read and highlight this passage of information using the highlighter tool.

1. use yellow to highlight the function(s) of the cell membrane

there are 2 functions discussed on this slide.
the cell membrane is the \gatekeeper\ of the cell. it controls what can be transported into the cell and what can exit the cell. this is important in keeping the cell functional and healthy. for example, waste products need to be removed from the cell, while molecules like glucose need to be brought into the cell. the cell membrane also has an important function in cell signaling. this is how cells communicate with each other and with their external environment.
the cell membrane is largely formed of a phospholipid bilayer. \bi\ means two, so \bilayer\ means that there are two layers of phospholipids. the hydrophilic phosphate heads of the phospholipids face outwards and the hydrophobic fatty acid tails face inwards, opposite other fatty acid tails. this hydrophobic region inside the cell membrane makes it hard for polar molecules and ions to pass through directly. large molecules also cannot \slip through\ the phospholipid bilayer.

Explanation:

The text states that the cell - membrane controls transport into and out of the cell and is involved in cell signaling. These are the two functions to highlight.

Answer:

The cell membrane is the "gatekeeper" of the cell. It controls what can be transported into the cell and what can exit the cell. The cell membrane also has an important function in cell signaling.