DNA is a double-stranded helical macromolecule consisting of nucleotide monomers with backbone and four different bases adenine (A), cytosine (C), guanine (G) and thymine (T). In humans, DNA is located on the chromosomes in the nucleus of a cell, with a stretched length of about 2 meters. The total length of DNA present in all 1013 cells of an adult human is about 2 x 1013 meters, which equals to nearly 70 trips from earth to the sun and back. DNA encodes for proteins, and proteins act as ‘factory workers’ who actively carry out metabolic functions: for example, several different proteins are crucial in the process of DNA synthesis. These protein molecules make sure there is almost no error during DNA replication. Erroneous DNA carries altered genetic information, which can result in evolution, but also in cancer and genetic diseases. Ruthenium compounds are special synthetic molecules, which can mimic iron, selectively enter cancer cells, and thus are considered as new type candidates for anti-cancer pharmaceuticals. Dimeric ruthenium compounds that bind and insert into DNA selectively at AT region, blocking particular genes, thus prevent diseases, which may be interesting for future pharmaceutical development. Lysozyme, an antibacterial enzyme dissolves bacterial cell walls, leading to cell death. Structural rearrangements of human lysozyme upon pH variations were studied by NMR.