Biological clock

Timekeeping mechanism [³] that it is thought that a creature comprises it with the biological clock (hit result get out, and is biological clock ^{[1] [2]}) by nature [¹]. I say biological clock (there is not a sea bream get out and is) [³] [²], the physiological clock (physiolosical clock) [¹]. I affect it in the period of sleep and the action of the creature. According to the suprachiasmatic nucleus of the brain, I am considered in the mammals. A well known biological clock has circadian rhythm.

Table of contents

General statement

The biological clock is structure measuring time considered that a creature comprises it by nature. Biological clocks do not usually come up in the consciousness of the person. However, I have a big influence on a period or the action of the sleep, and the action of the nocturnal diurnal animal is controlled in a biological clock. For example, gastric acid and a degrading enzyme are prepared for before a diet beforehand, but these depend on a life clock, too, and the life clock is indispensable if I let you show the ability of the individual to the maximum. In addition, share limited space in the insects by bringing time lag at activity time, and increase the opportunities of the encounter with similar opposite sex, and perform "distribution with "the time living apart" that is important to animal survival at the time of the action" (Okayama University Kenji Tomioka); [⁴].

A biological clock is known to surely exist from looking at the position of the sun when a bird migrates, and being able to establish a direction (sun compass) [¹]; [⁵]. Besides, a bee is separated from the outside world, and I am assumed in the den where the light of the day does not enter by a friend because the method to tell a friend about a direction of the honey by a dance makes a direction at the time of the sun a standard when clock mechanism intervenes there [²]. In addition, the phenomenon that the formation of a flower, the bud of the plant is influenced on a long day has close relation to clock mechanism [²].

The interest of the biologist in biological clock increased from about 1960 [²]. It was similar in Japan, and a study became active, and a creature rhythm society for the study was created in the 1970s and developed into Biological Society in Japan time in the 1990s.

Circadian rhythm

Some biological clocks are known, but, for example, with circadian rhythm (circadian rhythm), the photoperiodicity (photoperiodic) [⁵]. There is the thing of the unit (age unit) as seen in the flowering of excursion, the plant of ferry, the fish of the bird with the thing of a second, the share unit by the periodic variation of the reduction degree of the oxidation-reduction coenzyme, the thing having a long it in the period when there are again heartbeat, brain waves of the heart [²] with the thing in a period having a short it when there are states [²] from the thing which is short in a period to a long thing in a season, too [²]. But there is known to be not only the periodic thing but also the thing called "timer type biological clock" (hourglass type biological clock) to show only progress of a given period of time [¹].

It is diurnal mechanism that is particularly well known [²]. I separate an animal, a plant from natural environments, and, in the cause of the steady light not to change in time, the density of the discharge material of the animal knows that clock mechanism is inherent in the animals and plants on a day because there are many things indicating the lap rhythm [²]. But I do not know it in detail where is the mechanism in what kind of form, structure [²]. But the lap rhythm system does not move exactly in a period for 24 hours on the internal day of the creature. It slips off in the direction delayed little by little (in many cases). I call it "circadian rhythm" (circadian rhythm) "circadian rhythm" for such a reason [²]. Because there are the light and shade by having sunshine or not, noon, night as for the creature living in the natural world, I revise the gap of the biological clock using it [²].

Even if the life clock of the creature interrupts environmental influence, I can continue the rhythm of the period for approximately 24 hours. The life rhythm in a period is confirmed for 24 hours even if I keep this not to be able to judge time from a rat experiment from information of temperature and the brightness under the temperature, the brightness of the constant condition [⁴].

Place of the biological clock

 

Suprachiasmatic nucleus

The existence place of the biological clock varies according to an animal, and there is it to a suprachiasmatic nucleus in a little of the part where the optic nerve of right and left intersects in the mammals. The rhythm of the night and day of 24 hours disappeared in the rats that a suprachiasmatic nucleus was destroyed, but other conspicuous obstacle was not seen. From this, thought to be the organ which a suprachiasmatic nucleus is specialized as a life clock, and functions [⁴].

Structure of the life clock

One organic one to take a biological clock on holds the function of the biological clock, and protein generated in that plays a role as the pendulum, but is finished in around several minutes when I cannot do more than one by one of the intracellular chemical reaction. I restrain the work of the clock gene making protein so that a clock gene creates the protein taking the role of this pendulum, and there is not too much protein same as oneself when this protein increases. In other words, a reaction advances in the direction that protein decreases if protein increases in a cell, and the protein reacts to the direction to increase when protein decreases. "Negative feedback mechanism" means this. Because intracellular protein performs the increase and decrease (vibration) in a period for approximately 24 hours, by this work, the creature plays a role as the clock. The mechanism of this life clock was common to a eukaryote from mold to Homo sapiens [⁴].

Footnote

1. ^ ^{a b c d e} Iwanami biology dictionary
2. ^ ^{a b c d e f g h i j k l} The ^m Encyclopaedia Britannica [biological clock]
3. The ^ ^{a b} Koujien sixth edition [biological clock]
4. ^ ^{a b c d} "some the Newton separate volume time revised edition" (Newton press May 15, 2013)
5. ^ ^{a b} digital vast address spring

Allied item

• Melatonin
• Circadian rhythm sleep disorder
  • Sleep aspect progress syndrome、Sleep aspect retreat syndrome、Non-24 hours sleep awakening syndrome、Jet lag
• Light therapy
• Stomach clock

It is acquired by "https://ja.wikipedia.org/w/index.php?title= biological clock &oldid=59531352"

This article is taken from the Japanese Wikipedia Biological clock

This article is distributed by cc-by-sa or GFDL license in accordance with the provisions of Wikipedia.

Wikipedia and Tranpedia does not guarantee the accuracy of this document. See our disclaimer for more information.

In addition, Tranpedia is simply not responsible for any show is only by translating the writings of foreign licenses that are compatible with CC-BY-SA license information.