Semi-conservative DNA replication means that one stand is new DNA and the other contains a newly synthesized strand.
That is a chemical change or reaction.
Its renewed again and again by natural water cycle
i had this question and it was price
hope this helps
Protein
Proteins are the most versatile
macromolecules in living systems and they play important roles in essentially
all biological processes. Protein makes up the capsid of a virus. The infective
extracellular form of a virus known as a virion contains at
least one unique protein synthesized by specific genes in the nucleic acid of
that virus. In almost all viruses, at least one of these proteins forms a shell
(called a capsid) around the nucleic acid. Certain viruses also have other
proteins internal to the capsid. Some of these proteins act as enzymes during
the synthesis of viral nucleic acids.