respiratory quotient

Thân thiện

A scientist calculates the respiratory quotient of a plant in a sealed chamber.

Definition

1. 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.

Học thuật

Noun

1. 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