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...
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...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 .
N fowleri has three stages of their cycle. In the amoeboid trophozoite stage, they are infectious and measure 10-35 µm long. The trophozoite transforms to a non-feeding flagellate when food sources are limited. Flagellates are motile and measure 10-20 µm in length. The amoeba or flagellate will form a cyst, the dormant stage, if the environment is too cold and not conducive to continued feeding and growth. When the organism is in the cyst stage, it has a single layered wall and only one nucleus. The cyst measures 7-1...
The notion of circadian rhythms was first documented in the eighteenth century when it was determined based on observation that the closing and opening of heliotrope plant leaves occurred independently of sunlight, which was recorded by the French astronomer de Mairan. It is clearly evident now that almost all surfaces of physiology exhibit rhythmic oscillations from the simplest of bacteria to us human beings (10). As a biological clock, circadian rhythms develop to accomplish a steady entrainment to environmental cycles such as light. Additionally, circadian rhythms also serve two main functions, which is to measure the duration of time and to track the time of the day. These two functions are intertwined with one another being that both
Our bodies go through these biological timers, and continue to do so if we accept them, or not. Supporting this, we look at sleep, where the cycle of non-REM to REM changes asymmetrically throughout our phases spent unconscious. Whereas a few lost hours of sleep left me exhausted the next day, bringing down energy that I had from the day before. However, all is not lost because the circadian rhythm can be reset if proper action is taken to make sure the body is getting what it needs; preparing for sleep, and allowing our anatomy the perfect
Circadian rhythms are endogenous and self sustaining in all animals and plants. These rhythms are present in the absence of environment clues such as light, temperature and social clues. In absence of clues, animals free run in constant darkness due to programmed genetic interactions. Some of the genes involve in this processes are Per, Clock and Cry. The expressions of these genes are tightly regulated at molecular level by proteins which bind to promoters and repressors to create a rhythm throughout the day. For example, bmal and clock bind to ebox region to produce cry and mper proteins (Hong and Chong, 2007). These proteins are concentration dependant which means high level binds to repressor region to avoid further transcription. Such oscillations work on close to 24 hour cycle in animals and plants. These processes occur without any environmental clues. In case the environment clues are introduced to animals, they tend to synchronize internal clock with external signals. One such example of synchronization is shown in dorsophilia which increase Tim protein at night and the presence of external light decrease the production of Tim protein. This results into phase delay in dorsophilia (Leuloup and Goldbeter, 2001).
Circadian rhythms are part of the daily lives of humans. They cue our levels of alertness, our need for sleep, and our time of waking. To better understand these rhythms, scientists from around the globe have participated in difficult research for years. As of yet, the research shows that light, hormones, exercise, age, and a variety of other factors are important in determining circadian rhythms. Perhaps in the future, scientists will be able to manipulate circadian rhythms so that people no longer feel fatigue. By then, maybe Tomas Izquierdo could finally get some long overdue sleep.
Just like all of Earth’s green, society too has found a simple way to use the sun to its fullest potential. Daylight Saving Time is a function that has allowed us to enjoy longer summer days simply by moving our clocks an hour ahead in the spring. This method had became something to consider since Ben Franklin idealized it. Of course it's not the same for everyone, depending on where you are may change when Daylight Saving Time occurs. Although some may say Daylight Saving Time is pointless, it is vital that DST has its benefits.
Talaro , K., & Chess, B. (2012). Foundations in microbiology. (8th ed., pp. 563-564). New York, NY:
Every person, animal, living creature has body functions that are controlled by internal cycles. Many of their functions are controlled differently than others. Most that function on circadian rhythms tend to be less active during the night and more active during the day. For example, many “species are remarkably diverse and flexible in their daily activity patterns, including a spectrum of diurnal, day-active, to nocturnal, night-active” (Phillips 2013). Birds fly, eat, etc. during the day and sleep at night. Then again there is the owl which is the opposite. They sleep during the day and perform actively during the night.
Our bodies rely on two different things to let our bodies know when we need to be asleep. One is called the circadian rhythm, which is the physical, mental and behavioral changes that follow a twenty four hour cycle, that revolves around the light and dark of the day. Basically, our bodies are like our own little clocks which are controlled by a part of the brain called the suprachiasmatic
...nvironmental Microbiology. New York: A John Wiley & Sons, Inc; 1992. pp. 125?156. Accessed December 2, 2013.
Microbes are everywhere in the biosphere, and their presence invariably affects the environment in which they grow. The effects
Every organism requires a specific environment in order to survive. Bacteria alike, different types of bacteria are able to survive and reproduce in different types of environment. Some factors that affect the growth of bacteria include temperature, presence of certain gases and pH of the medium it is in.
The energy extracted today by the burning of coal and petroleum products represents sunlight energy captured and stored by photosynthesis almost 200 million years ago. A third very interesting group of bacteria synthesize sugars, not by using sunlight’s energy, but by extracting energy from inorganic chemical compounds; In a (d) deep sea vent, chemoautotrophs, such as these (e) thermophilic bacteria, capture energy from inorganic compounds to produce organic compounds.
With the mentor Rekha Balachandran, her research project is astonishing to me due to the concentration on circadian rhythm. As my background in psychology and biology, I have acknowledged that circadian rhythm is known to play a significant role in human physiological wellness. Disruption in circadian rhythm could affect metabolism poorly with the involvement of eating disorder as well as difficulties in storing information in short-term memory; improper functioni...
In a majority of circadian rhythms there seems to be major components which include an endogenous component (which is regulated by an internal clock located in the hypothalamus) and an exogenous component. This exogenous component is made up of different clues in time in the world around us....