 Marine invertebrates use symporters to transport against strong chemical gradients.Amino acids and sugars are taken up from sea water in the presence of extracellular sodium and is driven by the NA+/K+-ATPase pump.In the roots of plants, the H+/K+ symporters are only one member of a group of several symporters/antiporters that specifically allow only one charged hydrogen ion (more commonly known as a proton) and one charged K+ ion.