respiratory quotient
Definition
- Noun:
- A physiological measurement: The respiratory quotient (RQ) is a dimensionless number representing the ratio of the volume of carbon dioxide produced (VCO₂) to the volume of oxygen consumed (VO₂) by an organism, tissue, or cell during respiration over a specific period.
Usage
- The respiratory quotient is a key indicator in metabolic studies.
- Scientists calculated the respiratory quotient to determine the primary fuel source being metabolized.
- An respiratory quotient of 1.0 typically indicates carbohydrate metabolism.
Examples
- Noun:
- Measuring the respiratory quotient helps physiologists understand an animal's energy metabolism.
- A shift in the respiratory quotient from 0.7 to 1.0 suggested the subject had switched from burning fat to burning sugars.
Advanced Usage
- "To have a respiratory quotient of...": Used to state the specific calculated value.
- During intense exercise, muscles can have a respiratory quotient approaching 1.0.
- In a research context, it is common to see "RQ" used as an abbreviation after the term has been defined.
- The respiratory quotient (RQ) was measured continuously.
Variants and Related Words
- RQ: The standard abbreviation for respiratory quotient.
- Respiratory Exchange Ratio (RER): A closely related term often used interchangeably with RQ in whole-body measurements, though technically RER can be influenced by non-metabolic factors like hyperventilation.
Synonyms
- Metabolic ratio: A more general term that can refer to the RQ or similar measurements.
- CO₂/O₂ ratio: A descriptive synonym that explicitly states the components of the quotient.
Notes on Different Meanings
- The term respiratory quotient has a single, specific scientific meaning in physiology and biochemistry. It does not have common idiomatic or figurative uses outside this technical context.
Noun
-
the ratio of the volume of carbon dioxide expired to the volume of oxygen consumed by an organism or cell in a given period of time
