Circadian Clocks Essay example -- Biology

What is a circadian clock? A circadian clock is an internal biological clock that is found in almost all organisms, which regulates many metabolic processes. This biological clock allows organisms to adjust physiologically to changes in the environment. It is also influential in an organism’s behavior based on environmental differences. What do circadian clocks regulate? In plants, circadian clocks control flowering, response to seasons, and photosynthesis such as the opening and closing of the stomata. In mammals, circadian clocks manage sleeping, waking, feeding, and controlling whether an animal is nocturnal (most active at night) or diurnal (most active during the day). In cyanobacteria, circadian clocks regulate nitrogen fixation. In general, circadian clocks direct cell replication, amino acid uptake, and carbohydrate synthesis. Why are circadian clocks important? Circadian clocks are an integral part of everyday life for most all organisms on Earth. They regulate the most important functions in each organism. Without these biological clocks, processes such as metabolism would be completely disorganized and all of our bodies would go entirely awry. Life as we know it today would not exist in the regular predictable pattern. It’s as easy as Kai A, B, C! General Info about Cyanobacteria: (the organisms studied in this experiment) * Cyanobacteria are among the oldest organisms on Earth * They are very diverse: different species of cyanobacteria can survive in a broad range of environmental conditions * Even though cyanobacteria are unicellular, they perform many metabolic activities: photosynthesis, carbon fixation, and nitrogen fixation * Their circadi... ...rol the growth of tumors. Studies like this may eventually even lead to a cure for cancer! References Ditty, J.L, S.B. Williams and S.S. Golden. 2003. "A Cyanobacterial Circadian Timing Mechanism." The Annual Review of Genetics 37:513-517. Available at . Golden, Susan S. 2003. "Timekeeping in bacteria: the cyanobacterial circadian clock." Current Opinion in Microbiology 6:535-540. Available at . Johnson, Carl H. and Martin Egli. 2004."Visualizing a biological clockwork's cogs." Nature Structural & Molecular Biology 11(7):584-585. Available at . Vakonakis, Ionannis and Andy C. LiWang. 2004. "Structure of the C-terminal domain of the clock protein KaiA in complex with a KaiC-derived peptide: Implications for KaiC regulation." PNAS 101(30):10925-10930. Available at .