A researcher designs an experiment to investigate the effect of environmental temperature on the function of an enzyme. For each trial included in the experiment, the researcher will add the enzyme and its substrate to an aqueous buffer solution and then measure the amount of product formed over 20 minutes. Which of the following must remain the same for all trials of this experiment?A. The initial concentration of the substrate B. The final concentration of the product C. The three-dimensional structure of the enzyme D. The temperature of the aqueous buffer solution

The initial concentration of the substrate(Keeping the initial substrate concentration steady permits the specialist to think about the response rates under various natural conditions. The response rates will furnish the scientist with data about the protein's capacity in various situations).
A substrate is a substance that is used to make a final product. It is changed and reformed during the process. Sometimes chemical groups are added or taken away.
In the cell, enzymes bind and change substrates into their final product. When the enzyme is bound to the substrate, it is known as an enzyme-substrate complex.
Substrate concentration is the amount of substrate present that can be turned into a product. The unit of measurement usually assigned to eggs is dozen. Substrate concentration can be measured in various ways. Since the substrates inside the cell are suspended in cellular fluid, the substrate concentration is most commonly measured in molar concentration, or molarity (M), which is moles per liter.
Hence,the correct answer is option A "the initial concentration of the substrate.