Best I can express is from a biology 101 college textbook.
1. Enzyme must have the proper shape to bind the substrates in its active site. (Lock and key)
2. Once molded around the substrates, enzyme facilitates the catalysis reaction. Lowers the energy barrier allowing chemical bonds to be rearranged.
3. The combined “product” of the two substrates is then released from the enzyme.
4. The enzyme is not permanently changed, so it can be recycled to perform reactive task again and again.