These macromolecules are polar [polar: having different ends] because they are formed by head to tail condensation of polar monomers. Let's look at the three major classes of macromolecules to see how this works, and let's begin with carbohydrates.
Bostwick Steel Lath Company advertisement for steel truss loop type metal lath in 1920. A lath or slat is a thin, narrow strip of straight-grained wood used under roof shingles or tiles, on lath and plaster walls and ceilings to hold plaster, and in lattice and trellis work.
Platinum is a soft, dense, ductile metal that is very resistant to corrosion. It is used to make jewelry, wire, electrical contacts and laboratory vessels. Platinum expands at nearly the same rate as soda-lime-silica glass, so it is used to make sealed electrodes in glass systems.