What 3 functions do proteins have in a plasma membrane?*

Explanation:

Proteins in the plasma membrane have several functions based on their components, location etc. For instance, if the protein transcends the entire plasma membrane it could be a transport protein, responsible for the import and export of certain molecules between the cell and the extracellular matrix (ECM). If the proteins are resting at the surface of the cell, facing the ECM, their role could be to detect components in the ECM, relaying a series of messages back to the nucleus so that the cell can ‘decide’ what it should do with this information (is it being told it should undergo apoptosis, should it begin to divide, should it migrate?). As well as this, it could be involved in the detection of foreign bodies such as pathogens. This is an extremely job for these proteins because if the cell does come in contact with a pathogen, the cell can use these proteins to engulf the pathogen and through a series of steps, present the antigen on their major histocompatibility complexes (either 1 or 2 depending on the cell type) or HLA’s for human cells. Thus it can be concluded that protein functions vary widely in the plasma membrane and due to the vast number of proteins that can be found there, it’s difficult to narrow down the exact main of functions of all these proteins put together.

answer:

the water molecules are transferred from the roots to the stem or top parts of the tall tree because of important properties of water which are adhesion, cohesion and capillary action. cohesion is the property of water molecules keeps water molecules in a combined state by sharing of bonds between them at the atomic level. adhesion allows the interaction of water molecules with other substances or substrate. adhesion will cause the attachment of water molecules to the wall of the vessel (xylem) of the plant. capillary action occurs when the adhesive force to the vessel wall is stronger than the cohesive force between water molecules. capillary action mimics the transfer of water from a tube or pipe. in this way water utilizes its property to transfer water from down to top level of the plant.