The rate of passive transport depends on the permeability of the cell membrane, which, in turn, depends on the organization and characteristics of the membrane lipids and proteins. The four main kinds of passive transport are diffusion, facilitated diffusion, filtration and osmosis.
DEFINITION of 'Privately Owned'. A company that is not publicly traded on a securities exchange. The majority of companies are privately owned, usually by either one individual or by a small group of individuals. Although offering securities for sale to the public can be a good way to obtain large amounts of financing, public ownership requires considerable effort to ensure compliance with securities regulations.
As of 2016, the largest ten privately owned companies are the following (the revenue is based on 2015 data): 10 - Mars Revenue: $33 billion Founded by Frank C. Mars in 1911, Mars Incorporated is owned by Mars family. Apart from food and beverages ...