ABSTRACT. Collapse of Mount Pinatubo's edifice during its explosive eruptions on June 15, 1991, created a 2.5-kilometer-wide caldera. By early September 1991, a lake began to form on the caldera floor, mainly by spring discharge from the walls of the caldera augmented by rainfall and surface runoff.igure 1. Progressive development of the Pinatubo caldera lake. A, Pinatubo caldera on August 1, 1991, before the caldera lake began to form (photographed from the northwest by T. Casadevall, USGS). B, Pinatubo caldera lake as seen on September 10, 1991 (photographed from the northwest by T. Pierson, USGS).
Enzymes are central to every biochemical process that occurs in the body. Most enzymes are proteins . There are exceptions, however. For example, there are catalytic ribonucleic acid (RNA) molecules called ribozymes that are involved in RNA processing, and, in 1994, the first DNA enzyme was engineered.
Primase is an enzyme that synthesizes short RNA sequences called primers. These primers serve as a starting point for DNA synthesis. Since primase produces RNA molecules, the enzyme is a type of RNA polymerase.Primase functions by synthesizing short RNA sequences that are complementary to a single-stranded piece of DNA, which serves as its template.hese primers serve as a starting point for DNA synthesis. Since primase produces RNA molecules, the enzyme is a type of RNA polymerase. Primase functions by synthesizing short RNA sequences that are complementary to a single-stranded piece of DNA, which serves as its template.