Tsirkadnye rhythms. The measurement of time independent of temperature

you are: Tsirkadnye rhythms

One of intriguing features tsirkadnyh rhythms - that the length of the period largely practically does not depend on temperature (fig. 12.4). From the functional point of view it it is no wonder as any hours would be a bad measuring instrument of time if speed of their course depended on such external factors as temperature fluctuations!

And still it is difficult to imagine the biological mechanism of indemnification of temperature; therefore the number of basic schemes which could be logically offered for an explanation of rhythms, is limited. As the majority of metabolic reactions strongly depends on temperatures, in one of theories it is supposed that in hours there are two different processes, subject to the temperature influence one of which at its increase is accelerated, and another is slowed down. As a result of this internal indemnification speed of a course of hours can be independent of temperature.

Other theory takes away a leading role lipidam in a membrane. If lipidy contain fat acids with a long chain which differ on length, and also on number and position of double communications degree of a saturation and length of chains of fat acids can regulate fluidity of a membrane. Shorter chains and nonsaturation lower temperature of hardening of liquid fats. Changes in fat acids of membranes occur in situ in reply to temperature changes, promoting maintenance concerning constant fluidity of membranes in a wide range of temperatures.

Some researchers believe that changes in length of chains and in saturation degree membrannyh lipidov occur and throughout each daily cycle and make a mechanism part ' hours '. If it so to us it will be clear how time measurement could be rather independent of temperature.