A plough (UK) or plow (US; both /ËplaÊ/) is a tool or farm implement used in farming for initial cultivation of soil in preparation for sowing seed or planting to loosen or turn the soil. Ploughs were traditionally drawn by working animals such as horses or cattle, but in modern times are drawn by tractors.
Polar/Nonpolar Regions. In a biological membrane, the phospholipids are organized into a bilayer, which serves as the framework in which the other components of the membrane are embedded.
Phospholipid has both hydrophilic region and a hydrophobic region. The membrane is a fluid structure with a mosaic of various proteins embedded in or attached to a double layer of phospholipids. Membrane proteins are dispersed, individually inserted into the phospholipid bilayer with their hydrophilic regions protruding.