The capsid is the protein shell that surrounds the core of a virus where its nucleic acid is located. The capsid is made up small sub units called capsomeres.
A virus consists of a nucleic acid which may either be RNA or DNA and is found in varying quantities in the virus. It is this nucleic acid that is vital to the virus' survival that is housed in the capsid.
A drug that targets the capsid and damages it will cause the nucleic acid to leak out of the virus and into the surrounding while other fluids foreign to the virus will get in rendering the virus totally impaired, and due to this the virus cannot survive but will speedily die.
Follicle cells in your scalp assemble proteins to build new hair. This most likely involves dehydration synthesis reactions.
Dehydration synthesis forms a peptide bond between amino acids and releases a water molecule. Amino acids connected via peptide bonds form a polypeptide chain, which then chemically interact with other polypeptides in order to create a complex three-dimensional structure of the protein.
Okay, biology isn't exactly my strongest subject (it never has been), but I'm pretty sure the answer is nucleotides. DNA is made up of nucleotides. Each nucleotide contains a phosphate group, a sugar group, and a nitrogen base. There are four different nitrogen bases: adenine (A), thymine (T), guanine (G), and cytosine (C). A always pairs with T, and G always pairs with C.