A cell membrane protects a cell from it's surroundings. The cell membrane controls the movement of substances from the outside and inside of cells and organelles.
I believe that the youth movement originated with the baby boomers, the huge generation born after the world war II. By 1970, 58.2 % of the population in America was under the age of 35 years. The economic boom of the 1950s meant more families could afford to send their children to College. College life gave the young people a sense of freedom and independence. It was on college campuses across the nation that youth protest movements began and reached their peak.