As a consequence of their ability to thrive in extreme conditions, the Archaea have become increasingly valuable. For example, the DNA polymerase of Thermus aquaticus, an Archaea found in the Yellowstone hot springs, is a heat tolerant enzyme that is crucially important in modern molecular biology laboratories, because of its use in the polymerase chain reaction. Archaea have also become important for commercial purposes. Their enzymes, sometimes called extremozymes, have made their way into
laundry detergent, for example, where they digest proteins and lipids in hot water or cold, and in extremely alkaline conditions, thus helping to remove life's little messes. see also Cell, Eukaryotic; Eubacteria; Polymerase Chain Reaction; Ribosome.
Cynthia A. Needham
Madigan, Michael T., John M. Martinko, and Jack Parker. Brock Biology of Microorganisms, 9th ed., Upper Saddle River, NJ: Prentice Hall, 2000.
Campbell, Neil A. Biology, 4th ed. Menlo Park, CA: Benjamin Cummings, 1996.
Madigan, Michael T., and Barry Marrs. "Extremophiles." Scientific American (April, 1997): 82-87.
Attention deficit/hyperactivity disorder (ADHD) is a condition characterized by inattention and/or impulsivity and hyperactivity that begins in children prior to the age of seven. Their inattention leads to daydreaming, distractibility, and difficulties sustaining effort on a single task for a prolonged period of time. Their impulsivity disrupts classrooms and creates problems with peers, as they blurt out answers, interrupt others, or shift from schoolwork to inappropriate activities. Their hyperactivity is frustrating to those around them and poorly tolerated at school. Children with ADHD show academic underachievement and conduct problems. As they grow older, they are at risk for low self-esteem, poor peer relationships, conflict with parents, delinquency, smoking, and substance abuse.
Was this article helpful?