ck

Ck is an abbreviation that can refer to several distinct concepts depending on the context. The term is used in biochemistry, fashion, and software, among other fields, and there is no single defining topic associated with it.

In biochemistry, CK stands for creatine kinase, an enzyme that catalyzes the transfer of a phosphate group from ATP to creatine, forming phosphocreatine and ADP. This reaction helps buffer and supply energy in tissues with high and fluctuating energy needs, such as muscle and brain. CK has three major isoforms: CK-MM (muscle type), CK-BB (brain and other tissues), and CK-MB (heart muscle). Clinically, measuring CK activity in blood can aid in diagnosing muscle damage and myocardial injury, though modern practice often relies more on troponin tests. Factors such as intense exercise, muscle injury, and certain diseases can elevate CK levels.

In fashion, CK refers to Calvin Klein, an American fashion brand founded in 1968. The brand is widely recognized by its initials, which appear on clothing, fragrances, and marketing materials. Calvin Klein has played a significant role in contemporary fashion and is known for its minimalist aesthetic and global presence.

In software, CKEditor is a popular open-source rich-text editor used in web applications. Developed by CKSource, it provides a customizable editing interface for integrating text editing capabilities into websites and content management systems. The project is commonly abbreviated as CK in developer discussions and documentation.

See also CK (disambiguation) for other uses of the term.