What are the characteristics of carrier protein?

Carrier proteins are a type of cell membrane protein that is involved in transporting substances across the membrane. Carrier proteins have these characteristics: 

• Specificity: Carrier proteins exhibit specificity in the substances they transport. Each carrier protein is designed to recognize and bind to a particular type of molecule, such as ions, sugars, or amino acids.
• Selective binding: Carrier proteins have one or more specific binding sites that can recognize and interact specifically with their substrate molecules for selective transport.  
• Ability to interact with molecules on both sides of the membrane: Carrier proteins have one or more transmembrane domains made up of hydrophobic amino acids, which allow them to interact with molecules on either side of the plasma membrane. 
• Undergo conformational changes: On binding to their substrate molecule, carrier proteins undergo conformational changes in their 3-dimensional structure. This change, which is triggered by the transported molecule, allows the protein to carry the molecule across the membrane. 
• Exhibit saturation: There is a maximum rate at which carrier proteins can transport molecules. Once all the binding sites are occupied, they cannot bind to any more molecules, and increasing the concentration of the transported substance won’t increase the transport rate. 
• Have regulatory regions: The regulatory regions in carrier proteins help to regulate their transport activity by phosphorylating or dephosphorylating such regions.