Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE enzyme ( id number, name text, location text, product text, chromosome text, omim number, porphyria text )
TABLE: CREATE TABLE medicine_enzyme_interaction ( enzyme_id number, medicine_id number, interaction_type text )
TABLE: CREATE TABLE medicine ( id number, name text, trade_name text, fda_approved text )

### Question ###
What are the names of enzymes whose product is not 'Heme'?

### Accurate SQL ###

SELECT name FROM enzyme WHERE product <> 'Heme'