"Reduced concentration of substrate" available can interfere with the "ability of an enzyme" to catalyse a reaction. The main use of enzymes is to increase "the rate of reactions".
<u>EXPLANATION:</u>
There are several factors that have an impact on the ability of an enzyme to catalyse a reaction.
These include temperature, pH levels, and the quantity of substrate as well as the reactant. When the "substrate concentration increases", the rate of the reaction also increases in the presence of an enzyme.
On the other hand, when the "substrate concentration is low", the enzyme cannot catalyse the reaction at a fast rate.
The definition of a light year is the unit of astronomical distance, though it is called a light year it is actually a measurement of distance, so the answer, "the time it takes light to travel 1 million km is the correct answer.
