Is there a differences between serum creatinine and ck-mb? i know they're both creatinine.

Creatine/creatinine: CK-MB (creatine kinase) is an enzyme that builds. Creatinine is a breakdown product of CREATINE. CK-MB adds phosphorus group to CREATINE (made by liver to provide energy) to make CREATINE PHOSPHATE (energy reserve molecule) which gets broken down at a constant rate to form CREATININE--a marker for kidney function. Meanwhile, CK-MB is marker for cardiac damage.