Respirometer
Encyclopedia
A respirometer is a device used to measure the rate of respiration
of a living organism by measuring its rate of exchange of oxygen
and/or carbon dioxide
. They allow investigation into how factors such as age, chemicals or the effect of light affect the rate of respiration. Respirometers are designed to measure respiration either on the level of a whole animal (plant) or on the cellular level. These fields are covered by whole animal and cellular (or mitochondrial) respirometry
, respectively.
A simple whole animal respirometer designed to measure oxygen uptake or CO2 release consists of a sealed container with the living specimen together with a substance to absorb the carbon dioxide given off during respiration, such as soda lime
pellets or cotton
wads soaked with potassium hydroxide
. The oxygen uptake is detected by displacement of manometric fluid in a thin glass U-tube connected to the container. When the organism takes in oxygen it gives off an equal volume of carbon dioxide. As this is absorbed by the soda lime, air is sucked in from the U-tube to keep the pressure constant, displacing the liquid. The rate of change gives a direct and reasonably accurate reading for the organism's rate of respiration.
As changes in temperature or pressure can also affect the displacement of the manometric fluid, a second respirometer identical to the first except with a dead specimen (or something with the same mass as the specimen in place of the organism) is sometimes set up. Subtracting the displacement of the second respirometer from the first allows for control of these factors.
The set up of modern respirometers is described in more detail under respirometry
. A Respirometer may also be called an oxygraph. Suppliers for whole animal respirometers are e.g. Sable Systems
, Qubit Systems, or Challenge Technology; for mitochondrial respirometers Oroboros Instruments, Hansatech, or YSI.
Respiration (physiology)
'In physiology, respiration is defined as the transport of oxygen from the outside air to the cells within tissues, and the transport of carbon dioxide in the opposite direction...
of a living organism by measuring its rate of exchange of oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
and/or carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
. They allow investigation into how factors such as age, chemicals or the effect of light affect the rate of respiration. Respirometers are designed to measure respiration either on the level of a whole animal (plant) or on the cellular level. These fields are covered by whole animal and cellular (or mitochondrial) respirometry
Respirometry
Respirometry is a general term that encompass a number of techniques for obtaining estimates of the rates of metabolism of vertebrates, invertebrates, plants, tissues, cells, or microorganisms via an indirect measure of heat production ....
, respectively.
A simple whole animal respirometer designed to measure oxygen uptake or CO2 release consists of a sealed container with the living specimen together with a substance to absorb the carbon dioxide given off during respiration, such as soda lime
Soda lime
Soda lime is a mixture of chemicals, used in granular form in closed breathing environments, such as general anaesthesia, submarines, rebreathers and recompression chambers, to remove carbon dioxide from breathing gases to prevent CO2 retention and carbon dioxide poisoning.It is made by treating...
pellets or cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
wads soaked with potassium hydroxide
Potassium hydroxide
Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...
. The oxygen uptake is detected by displacement of manometric fluid in a thin glass U-tube connected to the container. When the organism takes in oxygen it gives off an equal volume of carbon dioxide. As this is absorbed by the soda lime, air is sucked in from the U-tube to keep the pressure constant, displacing the liquid. The rate of change gives a direct and reasonably accurate reading for the organism's rate of respiration.
As changes in temperature or pressure can also affect the displacement of the manometric fluid, a second respirometer identical to the first except with a dead specimen (or something with the same mass as the specimen in place of the organism) is sometimes set up. Subtracting the displacement of the second respirometer from the first allows for control of these factors.
The set up of modern respirometers is described in more detail under respirometry
Respirometry
Respirometry is a general term that encompass a number of techniques for obtaining estimates of the rates of metabolism of vertebrates, invertebrates, plants, tissues, cells, or microorganisms via an indirect measure of heat production ....
. A Respirometer may also be called an oxygraph. Suppliers for whole animal respirometers are e.g. Sable Systems
Sable Systems
Sable Systems develops and manufactures equipment for whole animal respirometry and offers courses in respirometry....
, Qubit Systems, or Challenge Technology; for mitochondrial respirometers Oroboros Instruments, Hansatech, or YSI.