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.
Base metal is a catch-all term in the jewelry industry for metals used in costume jewelry. In metal working, base metal is any metal that is not one of the noble or precious metals. 1/10 10kt GF: 1/10 of the total weight must be 10kt gold.