respiratory quotient

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a number obtained by division.
achievement quotient the achievement age divided by the mental age, indicating progress in learning.
caloric quotient the heat evolved (in calories) divided by the oxygen consumed (in milligrams) in a metabolic process.
intelligence quotient IQ; a numerical expression of intellectual capacity obtained by multiplying the mental age of the subject, ascertained by testing, by 100 and dividing by the chronological age.
respiratory quotient RQ; the ratio of the volume of carbon dioxide given off by the body tissues to the volume of oxygen absorbed by them; usually equal to the corresponding volumes given off and taken up by the lungs. It varies with the fuel source used: for carbohydrates it is 1.0; for lipids 0.7; for proteins 0.8; and with overfeeding (lipogenesis) 1.0–1.3.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

res·pi·ra·to·ry quo·tient (R.Q., RQ),

the steady-state ratio of carbon dioxide produced by tissue metabolism to oxygen consumed in the same metabolism; for the whole body, normally about 0.82 under basal conditions; in the steady state, the respiratory quotient is equal to the respiratory exchange ratio.
Farlex Partner Medical Dictionary © Farlex 2012

respiratory quotient

n. Abbr. RQ
The ratio of the volume of carbon dioxide released to the volume of oxygen consumed by a body tissue or an organism in a given period.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

res·pi·ra·to·ry quo·tient

(RQ) (res'pir-ă-tōr-ē kwō'shĕnt)
The ratio of the carbon dioxide produced during tissue metabolism to the oxygen consumed; reflects net substrate oxidation; can be determined by indirect calorimetry.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

respiratory quotient (RQ)

the ratio of the volume of CO2 produced to the volume of O2 taken up in a given period of time. From RQ estimates it is possible to deduce what type of food is being oxidized. Carbohydrates have an RQ of 1.0, fats of 0.7 and proteins 0.9. An RQ lower than 0.7 indicates that organic acids such as malic acid are being oxidized (see CRASSULACEAN ACID METABOLISM): an RQ greater than 1.0 indicates that ANAEROBIC RESPIRATION is occurring.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
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