When an enzyme catalyzes a reaction:
a. substrate(s bind in the active site
b. products bind in the active site
c. the shape of the enzyme remains unchanged
d. the enzyme is consumed by thereaction?

Substrates bind in the active site. They fit like lock and key.

Because the earth is not round ,but it may seem round when viewed from ,our planet but true some points earth is not round was an oblate spheroid -a square that it squashed as globe however is not even a perfect oblate spheroid.in fact isaac newton's first proposed that earth was not perfectly round but it was an oblate spheroid instead.that mean a square that is squashed as its poles and swollen at the

Mg is used to measure mass