If the respiratory substrate is fat/carbohydrate, then RQ of the respiring cells will be less than 1.

Explanation

To determine whether the respiratory quotient (RQ) of respiring cells using fat or carbohydrate as a substrate will be less than 1, we can follow these steps:

### Step 1: Understand the Concept of RQ
RQ, or Respiratory Quotient, is defined as the ratio of the volume of carbon dioxide (CO2) produced to the volume of oxygen (O2) consumed during respiration. It can be mathematically expressed as:

\[ RQ = \frac{CO2 \text{ produced}}{O2 \text{ consumed}} \]

### Step 2: Analyze the RQ for Carbohydrates
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