Atp is called the energy currency of the cell because
a glucose is made of atp
b atp catalyzes all metabolic reactions.
c atp allows one organelle to be exchanged for another
d most of the energy that drives metabolism is supplied by atp

regulation of gene expression. gene expression can be regulated by various cellular processes with the aim to control the amount and nature of the expressed genes. these regulatory proteins bind to dna and send signals that indirectly control the rate of gene expression

explanation:

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme