Respiratory quotient-basic - class-XI

The respiratory quotient (R.Q) is the ratio of $CO _2$ produced to $O _2$ consumed, while food is being metabolized.
RQ = $CO _2$ eliminated / $O _2$ consumed
R.Q for proteins is less than 1 since, amount of $CO _2$ evolved is lesser than amount of $O _2$ consumed.
When organic acids are broken down as respiratory substrates under aerobic conditions the R.Q is more than one. Organic acids contain more oxygen than carbohydrates and therefore require less oxygen for their oxidation.
R.Q is equal to zero for CAM plants at night time since, no $CO _2$ is evolved and $O _2$ is continuously consumed.
Thus, option D is correct.

The respiratory quotient (RQ) is the ratio of $CO _2$ produced to $O _2$ consumed, while food is being metabolized.
RQ = $CO _2$ eliminated / $O _2$ consumed.
The value of RQ is infinity during anaerobic respiration, because $CO _2$ is produced but $O _2$ is not utilized. Thus, option B is correct and other options are incorrect.

The respiratory quotient (or RQ or respiratory coefficient), is a dimensionless number used in calculations of basal metabolic rate (BMR), when estimated from carbon dioxide production.
RQ = CO$ _{2}$ eliminated / O$ _{2}$ consumed. Thus, option A is incorrect. Photosynthetic coefficient is the specific light spectrum at which chlorophyll absorbs light. Thus, option B is wrong. Photosynthetic yield is the quantity of the end product of the photosynthesis. Thus, option C is wrong. The temperature coefficient (Q$ _{10}$) represents the factor by which the rate (R) of a reaction increases for every 10-degree rise in the temperature (T). The rate (R) may represent any measure of the progress of a process. Thus option D is correct.

CAM plants open their stomata only at night and absorbs $CO _2$, which then converted into malate by acidification. During night time oxygen is absorbed continuously but no $CO _2$ is evolved. There fore R.Q in night is zero. During day time, malate gets converted to $CO _2$ and $C _3$ photosynthesis occurs. During day time amount of $CO _2$ evolved is equal to the amount of $O _2$ absorbed. So, R.Q at day time is 1. So, in CAM plants, R.Q will be zero at night. Thus, option A is correct and other options are incorrect.

The respiratory quotient (R.Q) is the ratio of $CO _2$ produced to $O _2$ consumed, while food is being metabolized.
RQ = $CO _2$ eliminated / $O _2$ consumed
R.Q for proteins is less than 1. Because, amount of $O _2$ consumed is higher than amount of $CO _2$ eliminated. So, protein rich pulses have R.Q less than 1. Thus, option C is correct and other options are incorrect.

CAM plants open their stomata only at night and absorbs $CO _2$, which then converted into malate by acidification. During night time oxygen is absorbed continuously but no $CO _2$ is evolved. There fore R.Q in night is zero. During day time, malate gets converted to $CO _2$ and $C _3$ photosynthesis occurs. During day time amount of $CO _2$ evolved is equal to the amount of $O _2$ absorbed. So, R.Q at day time is 1. Since succulents are CAM plants, their R.Q at night is zero and day is 1. Thus, option D is correct and other options are incorrect.

In succulent plants, the stomata are open during night and during this time plants absorb carbon dioxide. During day time stomata are closed and no carbon dioxide is evolved. These plants respire during night time, when they can take oxygen through open stomata. The volume of carbon dioxide is less than typical aerobic respiration. In fact during night time, these plants fix carbon dioxide into organic acids. The respiratory substrates are incompletely oxidised and thus, respiratory quotient is less than one.

Respiratory quotient (RQ) is defined as the ratio between volume of carbon dioxide released to volume of oxygen absorbed. Opuntia is a succulent plant. Succulents open their stomata in night, when atmospheric carbon dioxide is fixed temporarily into organic acids like oxaloacetate and malate. During daytime the stomata are closed and organic acids are decarboxylated to release carbon dioxide which is used in the synthetic processes of photosynthesis. As there is no net evolution of carbon dioxide, the value of RQ is zero in succulents like Opuntia.

During aerobic respiration, $O _2$ is consumed and $CO _2$ is released. The ratio of the volume of $CO _2$ evolved to the volume of $O _2$ consumed in respiration is called the respiratory quotient (R.Q) or respiratory ratio. The respiratory quotient depends upon the type of respiratory substrate used during respiration. When carbohydrates are used as substrate and are completely oxidised, the RQ will be 1, because equal amounts of $CO _2$ and $O _2$ are evolved and consumed, respectively. When fats are used in respiration, the RQ is less than 1. When proteins are respiratory substrates the ratio would be about 0.9.

During aerobic respiration, $O _2$ is consumed and $CO _2$ is released. The ratio of the volume of $CO _2$ evolved to the volume of $O _2$ consumed in respiration is called the respiratory quotient  (RQ) or respiratory ratio. The respiratory quotient depends upon the type of respiratory substrate used during respiration. When carbohydrates are used as substrate and are completely oxidised, the RQ will be 1, because equal amounts of $CO _2$ and $O _2$ are evolved and consumed, respectively. When fats are used in respiration, the RQ is less than 1. When proteins are respiratory substrates the ratio would be about 0.9.

Respiratory quotient or R.Q is defined as the ratio of carbon dioxide evolved to oxygen taken in for respiratory break down of a substrate. The value of R.Q for oxidation of carbohydrates is unity and less than one for oxidation of fats and proteins. Thus if groundnut, which stores fats is used as respiratory substrate the value of R.Q will be less than one.

During aerobic respiration, $O _2$ is consumed and $CO _2$ is released. The ratio of the volume of $CO _2$ evolved to the volume of $O _2$ consumed in respiration is called the respiratory quotient (RQ) or respiratory ratio. Thus the following expression is used to calculate the value of RQ.
RQ= volume of $CO _2$ evolved/ volume of $O _2$ consumed.
The respiratory quotient depends upon the type of respiratory substrate used during respiration. When carbohydrates are used as substrate and are completely oxidised, the RQ will be 1, because equal amounts of $CO _2$ and $O _2$ are evolved and consumed, respectively. When fats are used in respiration, the RQ is less than 1. When proteins are respiratory substrates the ratio would be about 0.9.
Under conditions of starvation carbohydrates are not available and proteins or fats are used as cellular fuel and hence the expected value of RQ is less than unity.

R.Q. is the ratio of carbon dioxide evolved and the oxygen consumed during the process of respiration.

In succulent plants at night the stomata are open and carbon dioxide is fixed into organic acids. Thus at night there is no net carbon dioxide evolved. Hence, value of RQ is zero.

The respiratory quotient depends upon the type of respiratory substrate used during respiration. When fats are used in respiration, the RQ is less than 1. Groundnut and  castor seeds are fats storing seeds, the stored fats are mobilised during their seed germination. Hence, the RQ value is less than one for germinating groundnut and castor seeds.

R.Q. is the ratio of the volume of carbon dioxide evolved and oxygen consumed in respiration.

During aerobic respiration, $O _2$ is consumed and $CO _2$ is released. The ratio of the volume of $CO _2$ evolved to the volume of $O _2$ consumed in respiration is called the respiratory quotient (RQ) or respiratory ratio. Thus the following expression is used to calculate the value of RQ.
RQ= volume of $CO _2$ evolved/ volume of $O _2$ consumed.
At compensation point there is no net evolution of carbon dioxide. Hence, numerator in above expression is zero, giving the value of RQ as zero.

During the ripening of oil-seeds, when fats are formed from carbohydrates the respiratory quotient is greater than 1. This arises because part of the oxygen consumed in respiration is derived from carbohydrates.

During aerobic respiration, O$ _2$ is consumed and CO$ _2$ is released. The ratio of the volume of CO$ _2$ evolved to the volume of O$ _2$ consumed in respiration is called as the respiratory quotient (RQ) or respiratory ratio. Thus, the following expression is used to calculate the value of RQ.
RQ = volume of CO$ _2$ evolved/ volume of O$ _2$ consumed.
In an actively photosynthesizing tissue, the net volume of carbon dioxide evolved (i.e., volume of carbon dioxide produced in respiration minus that utilised in photosynthesis) is equal to net volume of oxygen (i.e., volume of oxygen consumed in respiration minus that evolved in photosynthesis). 

The respiratory quotient depends upon the type of respiratory substrate used during respiration. When organic acids are metabolised more carbon dioxide is evolved than oxygen consumed. Hence, the value of RQ is more than one.

Respiratory quotient (RQ) is defined as the volume of carbon dioxide released to the volume of oxygen absorbed during the process of aerobic respiration. 

Respiratory quotient is defined as the volume of carbon dioxide released to the volume of oxygen consumed during the respiration process. Its value is one for oxidation of carbohydrates and less than one for oxidation of fats and proteins. The value is more than one for oxidation of organic acids.

R.Q stands for respiratory quotient or respiratory ratio. It is the volume of CO$ _2$evolved to the volume of O$ _2$ consumed. It depends upon the type of respiratory substrate used during respiration. When carbohydrates are used as a substrate and are oxidized completely the RQ is 1.  For fats, it is less than 1 and for proteins, it is 0.9.

Respiratory quotient (RQ) is defined as volume of carbon dioxide released to volume of oxygen absorbed during the process of aerobic respiration of a substrate. 

Our food contains three main constituents: carbohydrates, fats and proteins. The amount of energy released when one gram of any of these food elements is burned is known as calorific value. Thus calorific value of food indicates as to how much is the energy value of food which the human body can gain through metabolism. It is usually given in kcal/gm. Fats form the most concentrated source of energy in our diet. 1 gram of fat yields 9.5 kcal of energy which is the highest among the food components. 1 gram of carbohydrates and proteins yield almost similar amount of energy which is equal to 4 kcal. 

Respiratory Quotient (R.Q.) is the ratio of the volume of CO$ _{2}$ released to the volume of O$ _{2}$ consumed in a respiration process. It depends on the nature of the substrate and its capacity of using O$ _{2}$ and releasing CO$ _{2}$. For example, glucose consumes 6 CO$ _{2}$ and releases 6 O$ _{2}$, so its R.Q. is 1.

The Respiratory Quotient (R.Q.) is the ratio of CO2 produced to O2 consumed. For carbohydrates, the ratio is 1:1, resulting in an R.Q. of 1.

Respiratory quotient or R.Q. is the ratio of volume of CO$ _2$ produced to volume of O$ _2$ consumed during cellular respiration. It is measured by Ganong's Respirometer. R.Q. for carbohydrates is 1, organic acid is >1 and fats and proteins is <1.

Compensation point is the value of a factor where the rate of photosynthesis is equal to the rate of respiration.  At this point, carbon dioxide released from respiration is equivalent to that which is taken up during photosynthesis. When the light intensity increases, the compensation point is reached. When light intensity is increased beyond the compensation point, the rate of photosynthesis increases proportionally until the point of light saturation is reached. Beyond light saturation point, the rate of photosynthesis is no longer affected by light intensity. Compensation point varies in different species of plants. It even varies in response to changes in temperature and other environmental factors.

The respiratory quotient depends on the type of respiratory substrate which is to release energy for the synthesis of ATP. If the respiratory substrate is a lipid, it consists carbon-hydrogen bonds mean more ATP is produced from them in respiration. This also means more oxygen is required to break them down, so has an RQ of less than one and if the substrate is glucose the RQ is 1.

R.Q. is the ratio of amount of CO$ _2$ produced to the amount of O$ _2$ consumed by the cell for respiration. R.Q. value of protein is 0.8 as the volume of carbon dioxide released is less than the amount of oxygen. Carbohydrates, organic acid and starch have R.Q. of 1 or greater than 1.

Respiratory quotient is the value, which depends upon the oxidation of respiratory substrate. It is calculated by amount of $CO _2$ eliminated to that of $O _2$ consumed.

Organic acids have more volume of $CO _2$ liberated during respiration than the volume of $O _2$ used. Therefore, the R.Q. value will be greater than one. E.g., R.Q of oxalic acid is 4.

The respiratory quotient is used in calculations of BMR when estimated from carbon dioxide production. It is calculated from the ratio of carbon dioxide produced by the body to oxygen consumed by the body. A  value of 0.7 indicates that lipids are being metabolized, 0.8 for proteins, and 1.0 for carbohydrates. RQ can be used as an indicator of over or underfeeding. Underfeeding, which forces the body to utilize fat stores, will lower the RQ and is marked by an RQ below 0.85, while overfeeding, which causes lipogenesis, will increase it and is indicated by RQ greater than 1.0.

Succulents do not evolve carbon dioxide during the night (when their stomata are open) as the same is in carbon fixation. They also change carbohydrates to organic acids which utilise oxygen but do not evolve carbon dioxide.

RQ slightly more than unity is found when organic acids are broken down as respiratory substrates under aerobic conditions, e.g. for the breakdown of oxalic acid liberation of $CO _2$ is more than $O _2$.
$RQ=\frac{4{CO} _{2}}{{O} _{2}}=4.0$.

If RQ value is more than 1, the respiration would be aerobic and anaerobic respiration.

When the RQ value is less than one for fats,  as fats consume more oxygen for respiration than carbohydrates.

The respiratory quotient (RQ) is the ratio of 
RQ = CO$ _{2}$ eliminated / O$ _{2}$ consumed.
When carbohydrates are being oxidized in the organism and the requisite oxygen is available, the RQ is 1. In the oxidation of fats, the RQ is 0.7 and in the oxidation of proteins, 0.8. Whenever the substrate is protein, RQ is always less than one (0.5-0.9). So, in germinating seeds, when protein is aerobically oxidized, the R.Q value will be less than one. Thus, option A is correct and other options are incorrect.

The respiratory quotient (RQ) is the ratio of CO$ _{2}$ produced to O$ _{2}$ consumed while food is being metabolized.
RQ = CO$ _{2}$ eliminated/O$ _{2}$ consumed.
The respiratory quotient for carbohydrate metabolism can be demonstrated by the chemical equation for oxidation of glucose.
C$ _{6}$H$ _{12}$O$ _{6}$ + 6 O$ _{2}$ 6 CO$ _{2}$+ 6 H$ _{2}$O
Because the gas exchange in this reaction is equal, the respiratory quotient for carbohydrates is: RQ = 6 CO2 / 6 O2 = 1. Thus, option A is wrong.
The chemical composition of fats differs from that of carbohydrates in that fats contain considerably fewer oxygen atoms in proportion to atoms of carbon and hydrogen. The substrate utilization of palmitic acid is:
C$ _{16}$H$ _{32}$O$ _{2}$ + 23 O$ _{2}$ 16 CO$ _{2}$ + 16 H$ _{2}$O
Thus, the RQ for palmitic acid is approximately 0.7. RQ = 16 CO$ _{2}$ / 23 O$ _{2}$ = 0.696. Thus, option B is wrong.
The respiratory quotient for protein metabolism can be demonstrated by the chemical equation for oxidation of albumin:
C$ _{72}$H$ _{11}$2N$ _{18}$O$ _{2}$S + 77 O$ _{2}$ 63 CO$ _{2}$ + 38 H$ _{2}$O + SO$ _{3}$ + 9 CO(NH$ _{2}$)2
The RQ for protein is approximately 0.8. RQ = 63 CO$ _{2}$/ 77O$ _{2}$ = 0.8. Thus, option C is wrong.
In case of organic fats, volume of CO$ _{2}$ given out during respiration is more than the volume of O$ _{2}$ used. Thus, option D is correct.

RQ value = volume of CO$ _2$ evolved/volume of O$ _2$ consumed.

The utilization of oxygen is nill in anaerobic respiration. Hence the R.Q. value is infinity. 

During aerobic respiration, ${O} _{2}$ is consumed and ${CO} _{2}$ is released. The ratio of the volume of ${CO} _{2}$ evolved to the volume of ${O} _{2}$ consumed in respiration over a period of time is called as respiratory quotient (RQ) or respiratory ratio.
$RQ=\frac{Volume,, of,, {CO} _{2} ,,evolved}{Volume ,,of ,,{O} _{2} ,,consumed}$.

The various organic substances such as carbohydrates, fats and proteins are respired completely to carbon dioxide and water are called respiratory substrates. Under natural conditions only carbohydrates are used. Glucose being the simplest monosaccharide hexose molecule acts as the chief respiratory substrate. 

The compensation point is the light intensity on the light curve for which the rate of photosynthesis is equal to the rate of respiration in the plant cell i.e., the rate of cellular fixation of Carbon dioxide through photosynthetic pathway is equal to the respiratory release of Carbon-dioxide and the release of Oxygen by photosynthesis is equals to the rate of consumption by respiration in a plant cell. At the compensation point, the organism is not building any biomass nor consuming any biomass.

The respiratory quotient (R.Q) is the ration of the volume of the CO$ _{2}$ released to the volume of the O$ _{2}$ utilized by a substrate during the process of respiration. It solely depends on the nature of the substrate. The R.Q. reflect the nature of the substrate, for example, R.Q. 1 indicated that glucose is the respiratory substrate.

The volume of carbon dioxide released and oxygen consumed in the process of respiration is called as respiratory quotient or R.Q of that substrate.

Respiratory quotient (RQ) is the ratio of the volume of carbon dioxide released to the volume of oxygen taken in respiration in the given period of time at standard temperature and pressure. 

During aerobic respiration, $O _2$ is consumed and $CO _2$ is released. The ratio of the volume of $CO _2$ evolved to the volume of $O _2$ consumed in respiration is called the respiratory quotient (R.Q) or respiratory ratio.  Thus the following expression is used to calculate the value of R.Q.
RQ= volume of $CO _2$ evolved/ volume of $O _2$ consumed.