Part of Lesson Plan: Making Cheese

Activity Overview / Details

Students read the background on how cheese is made.  Things to emphasize with students:

Cheese is created when enzymes break down the protein casein found in milk.

The enzyme found in the calf's stomachs is called rennin, which is produced only when they are young and nursing. This enzyme specializes in breaking casein and other similar proteins.  Alternatively, the recombinant kind is called chymosin, and is produced when the gene for rennin is inserted into a fungus, and grown in large quantities.  Without these enzymes, you can rely on bacteria to produce enzymes that will also cleave the protein.

The enzymes are specialized proteins that are coded for in DNA.  These proteins, like others, may only be produced in specialized cells.