keep a civil tongue in one's head. Speak politely, as in The teacher won't allow swearing; she says we must keep a civil tongue in our heads. This expression uses tongue in the sense of a manner of speaking, a usage dating from the 1400s. An early cautionary version was Keep a good tongue in your head, lest it hurt your teeth (1595). See also: civil, head, keep, tongue. n. a civil servant.
Phospholipids serve a major function in the cells of all organisms: they form the phospholipid membranes that surround the cell and intracellular organelles such as the mitochondria. The cell membrane is a fluid, semi-permeable bilayer that separates the cell's contents from the environment, see animation below.hospholipids serve a major function in the cells of all organisms: they form the phospholipid membranes that surround the cell and intracellular organelles such as the mitochondria. The cell membrane is a fluid, semi-permeable bilayer that separates the cell's contents from the environment, see animation below.
Best Answer: The usual phospholipid that we encounter is those found in the cell membrane, namely the membrane phospholipid. They are the predominant lipids of cell membrane. They can act as: 1) reservoir of intracellular protein messengers such as phosphoinositol biphosphate. just now. Report Abuse. Phospholipids make up the structure of the lipid bilayer found in the membrane of cells. Primarily, it's main job is to keep the things that are on the inside of a cell inside, and keep what things are outside the cell on the outside.