Fatty acids from Glycolipids and phospholipids, on the other hand, have two hydrophobic chains that are too bulky to fit into the a spherical shape as micelles do. Thus, they preferred to form glycolipids and phospholipids as lipid bilayers, which are discussed in the next section.
DNA Helicase-The enzyme responsible for separating the two strands of DNA in a helix so that they can be copied during DNA replication. DNA Ligase-The enzyme responsible for sealing together breaks or nicks in a DNA strand. Responsible for patching together Okazaki fragments on the lagging strand during DNA replication.
Of these photoproducts, the most important is the pyrimidine dimer formed between adjacent pyrimidine molecules on the same strand of DNA, which can interrupt both the transcription and the replication of the DNA. The formation of a dimer can be reversed by two repair mechanisms: photoreactivation and dark repair. Systematic quantitative study of photoreactivation, the more important of the two mechanisms, has suggested a two-step reaction scheme (4).