Which type of macromolecule is made up of subunits that are called amino acids?
a.) carbohydrate
b.) lipid
c.) nucleic acid
d.) protein

The macromolecule that is made up of subunits that are called amino acids are the protein. The answer is therefore letter D. The carbohydrates are made up of subunits called monosaccarides. The lipids are mades up of subunits referred to as the fatty acid while nucleic acid are made up of nucleotides.

Amino acids are the building blocks for proteins. They are organic compounds, and contain an amine, carboxyl, and a side chain. They fuse to form short chains called as peptides. Longer chains of amino acids are called as proteins. They contain C, H, O, and N as chief elements.

Single strand binding protein by peptide bond

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.