The ratio of carbon dioxide produced to oxygen consumed is known as
**Core Concept**
The question is testing the understanding of the respiratory quotient (RQ), which is a measure of the ratio of carbon dioxide produced to oxygen consumed during cellular respiration. The RQ is an essential concept in respiratory physiology and is used to estimate the type of fuel being metabolized by the body.
**Why the Correct Answer is Right**
The respiratory quotient is calculated as the ratio of the volume of carbon dioxide produced (VCO2) to the volume of oxygen consumed (VO2) per unit time. This ratio is influenced by the type of fuel being metabolized, with carbohydrates having an RQ of approximately 1, fats having an RQ of 0.7, and proteins having an RQ of approximately 0.8. The RQ is an important parameter in understanding the metabolic state of an individual and is used in various clinical and research settings.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is likely an incorrect or incomplete answer choice.
* **Option B:** This option is not a valid answer choice for the RQ, which is a specific ratio of CO2 production to O2 consumption.
* **Option D:** This option is not a valid answer choice for the RQ, which is a specific ratio of CO2 production to O2 consumption.
**Clinical Pearl / High-Yield Fact**
The respiratory quotient can be used to estimate the type of fuel being metabolized by the body. For example, an RQ of 1 suggests that carbohydrates are being metabolized, while an RQ of 0.7 suggests that fats are being metabolized.
**Correct Answer: C. Respiratory Quotient (RQ)**