15 million people were self-employed in 2015, or 10.1 percent of all U.S. workers. Self-employment continues to be an important source of jobs in the United States. In 2015, 15.0 million people, or 10.1 percent of total U.S. employment, were self-employed, including those who had incorporated their businesses and those who had not.
DNA helicase is the enzyme that unwinds the DNA double helix by breaking the hydrogen bonds down the center of the strand. It begins at a site called the origin of replication, and it creates a replication fork by separating the two sides of the parental DNA.
Restriction enzymes, also known as restriction endonucleases, are enzymes that cut a DNA molecule at a particular place. They are essential tools for recombinant DNA technology. The enzyme scans a DNA molecule, looking for a particular sequence, usually of four to six nucleotides. Once it finds this recognition sequence, it stops and cuts the strands. This is known as enzyme digestion. On double stranded DNA the recognition sequence is on both strands, but runs in opposite directions.