The cell membrane is essential for a cell to maintain balance which we call

Homeostasis

Explanation:

Cell membrane (plasma membrane) is known to be a semi-permeable membrane that regulates the movement of substances in and out of the cell. Similarly, it is a phospholipid bilayer that separates the outer (external) environment from the inner cellular environment. Thus, plasma membrane maintains homeostasis by regulating the movement of materials or cell contents that can pass in or out of the cell on order to main balance equilibrium.

hydroxyl -oh

alcohols, always polar, can form hydrogen bonds with h2o molecules

carboxyl -cooh  

cargoxylic acids, has acidic properties which is a source of hydrogen ions, found in cells in ionized for with a charge of oh-1

carbonyl > co

ketone if within skeleton, aldehyde if group is at the end of skeleton, k & a may be structural isomers, it determines 2 sugars (ketose & aldose)

amino -nh2

amines, acts as a base, it can pick up h+ ions from surrounding solution, ionized with charge of 1+

methyl ch2

addition to rna/dna affects and gene expression

phosphate -opo3 ²⁻

organic phosphates, contributes to negative charge to, molecule that it is a part of, and potential to react with h20

sulfhydryl -sh

thiols, cross-linking stabilize the protein, and it is structure