Question

What is correct about enzymes they are most active at ph=7.0 they all are amino acids they all are proteins they are most active at temperature of 0c?

Answer 1

They are most active at optimum pH (5-7).
Not all enzymes are amino acids some nucleic acids are also act as enzymes.
All enzymes are proteins but all proteins are not enzymes.
They are active at optimum temperature (298k-310k).