Community Supported Agriculture (CSA) is an alternative model for the distribution of agricultural products directly from the farmer to the consumer, it consists of a group of people who form a cooperative to grow and consume food. Through this socio-economic model, consumers lend their support to producers, in exchange for a direct and regular delivery of biological products, that is, producers and consumers support each other and share the benefits and risks of food production.
The plasma membrane is made up by a phospholipid bilayer with embedded proteins that separates the internal contents of the cell from its surrounding environment. Only relatively small, non- polar materials can easily move through the lipid bilayer of the plasma membrane.