This pertains to the structure of proteins. Secondary structures are stabilized by the presence of hydrogen bonds. The common types of secondary structures of proteins are the alpha helix and the beta sheets, each performing different functions.
Primary structure of protein is the peptide molecule comprised of peptide bonds. Once these peptide grows long enough, it will either be arranged into alpha helices or beta sheets stabilized by hydrogen bonds and this is the secondary structure. Once there is protein folding involved in the secondary structure of protein, then the folded protein is called the tertiary structure (or a protein subunit). When protein subunits come together to perform a specific function, then that is the quaternary structure.
Attached is a figure concerning the protein structures.
The skin will lose its elasticity since First-degree burns usually only affect the epidermis which isn’t where the nerves or glands are located
DNA is found in the nucleus of a cell. Depending on the type of cell, different parts of the DNA are used (example; if it's an eye cell, the DNA will use the segment that is dedicated to the functions of the eye). When a protein is needed, the DNA will split and in a process called transcription, the DNA messages are copied onto mRNA. The mRNA then leaves the nucleus through nuclear pores, and then travels through the cytoplasm to locate ribosomes which will produce the proteins needed to express whatever trait it codes for.
I believe it's aerobic exercise.