
The ''Q''
10 temperature coefficient is a measure of temperature sensitivity based on the chemical reactions.
The ''Q''
10 is calculated as:
:
where;
: ''R'' is the rate
: ''T'' is the temperature in
Celsius
The degree Celsius is the unit of temperature on the Celsius temperature scale "Celsius temperature scale, also called centigrade temperature scale, scale based on 0 ° for the melting point of water and 100 ° for the boiling point ...
degrees or
kelvin
The kelvin (symbol: K) is the base unit for temperature in the International System of Units (SI). The Kelvin scale is an absolute temperature scale that starts at the lowest possible temperature (absolute zero), taken to be 0 K. By de ...
.
:
Rewriting this equation, the assumption behind ''Q''
10 is that the reaction rate ''R'' depends exponentially on temperature:
:
''Q''
10 is a unitless quantity, as it is the factor by which a rate changes, and is a useful way to express the temperature dependence of a process.
For most biological systems, the ''Q''
10 value is ~ 2 to 3.
In muscle performance

The temperature of a muscle has a significant effect on the velocity and power of the muscle contraction, with performance generally declining with decreasing temperatures and increasing with rising temperatures. The ''Q''
10 coefficient represents the degree of temperature dependence a muscle exhibits as measured by contraction rates.
A ''Q''
10 of 1.0 indicates thermal independence of a muscle whereas an increasing ''Q''
10 value indicates increasing thermal dependence. Values less than 1.0 indicate a negative or inverse thermal dependence, i.e., a decrease in muscle performance as temperature increases.
''Q''
10 values for biological processes vary with temperature. Decreasing muscle temperature results in a substantial decline of muscle performance such that a 10 degree Celsius temperature decrease results in at least a 50% decline in muscle performance.
Persons who have fallen into icy water may gradually lose the ability to swim or grasp safety lines due to this effect, although other effects such as
atrial fibrillation
Atrial fibrillation (AF, AFib or A-fib) is an Heart arrhythmia, abnormal heart rhythm (arrhythmia) characterized by fibrillation, rapid and irregular beating of the Atrium (heart), atrial chambers of the heart. It often begins as short periods ...
are a more immediate cause of drowning deaths. At some minimum temperature biological systems do not function at all, but performance increases with rising temperature (''Q''
10 of 2-4) to a maximum performance level and thermal independence (''Q''
10 of 1.0-1.5). With continued increase in temperature, performance decreases rapidly (''Q''
10 of 0.2-0.8) up to a maximum temperature at which all biological function again ceases.
Within vertebrates, different skeletal muscle activity has correspondingly different thermal dependencies. The rate of muscle twitch contractions and relaxations are thermally dependent (''Q''
10 of 2.0-2.5), whereas maximum contraction, e.g., tetanic contraction, is thermally independent.
Muscles of some ectothermic species. e.g., sharks, show less thermal dependence at lower temperatures than endothermic species
See also
*
Arrhenius equation
In physical chemistry, the Arrhenius equation is a formula for the temperature dependence of reaction rates. The equation was proposed by Svante Arrhenius in 1889, based on the work of Dutch chemist Jacobus Henricus van 't Hoff who had noted in 188 ...
*
Arrhenius plot
*
Isotonic (exercise physiology)
*
Isometric exercise
An isometric exercise is an exercise involving the static contraction of a muscle without any visible movement in the angle of the joint. The term "isometric" combines the Greek words ''isos'' (equal) and ''-metria'' (measuring), meaning that i ...
*
Skeletal striated muscle
Skeletal muscle (commonly referred to as muscle) is one of the three types of vertebrate muscle tissue, the others being cardiac muscle and smooth muscle. They are part of the somatic nervous system, voluntary muscular system and typically are a ...
*
Tetanic contraction
References
{{DEFAULTSORT:Q10 (Temperature Coefficient)
Ecological metrics
Chemical kinetics