<span>Enzymes have three main characteristics. First, they increase the rate of a natural chemical reaction. Secondly, they typically only react with one specific substrate or reactant, and thirdly, enzyme activity is regulated and controlled within the cell through several different means, including regulation by inhibitors and activators. It is possible to group enzymes into different categories, including oxidases, transferases, hydrolases, lyaes, isomerases and ligases. In naming enzymes, the "-ase" suffix is often appended to the name of the substrate molecule upon which which the enzyme reacts. For example, the enzyme sucrase catalyzes the transformation of the sugar sucrose in to glucose and fructose. In this case, the "sucr-" suffix represents the molecule upon which the sucrase enzyme reacts. Not all enzymes are named according to this convention.</span>
Answer: 
Explanation:
Alpha Decay: In this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. The mass number is reduced by 4 units and atomic number is reduced by 2 units.
General representation of an element is given as:
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
General representation of alpha decay :
The balanced nuclear equation when the isotope Strontium-90 decays by Q- decay is :

F. hold on to their protons more strongly