Protein molecules serve as transporters of molecules across the cell membrane.
Movement of molecules against their concentration gradients is a form of active transport.
Proteins are organic molecules which are made from amino acids linked together by peptide bonds.
Proteins embedded in the cell membranes serve as transport molecules as well as receptors.
Based on concentration gradients, proteins can function in passive or active transport.
Learn more about proteins at: https://brainly.com/question/10058019
