Greetings, so the cell membrane primary component will be lipids, this is what gives the prominent feature that the cell membrane semi permeable and is "leaky' to allows molecules to diffuses inside and out of the cell through various mechanisms. However, the cell membrane does contain proteins (transmembrane proteins) that not only aid in the structure of the membrane but holds numerous other effects such as transport of molecules, protection of various bacteria such as gram negatives, cell signaling and signal cascade, etc.
