Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Protein Activity
Name: Russell
Status: Student
Grade:  9-12
Location: N/A
Country: United States
Date: July 2008


Question:
Cannot find a definite answer to the following question: Explain what is meant by biological activity of a protein?



Replies:
The biological function of a protein is either structural (collagen, for example), carrier (hemoglobin, for example), enzymatic (trypsin, for example), regulatory (receptor proteins and insulin, for example), mechanical (myosin, for example). Google "functions of proteins" for others.

Good luck,

Ron Baker, Ph.D.


In general, proteins are designed to 'attach' to biological molecules. They might attach to each other to form structural units in the cell, or they might attach to other biological molecules to do specific tasks (such as catalyze a chemical reaction). These functions are known as the protein's 'biological activity'.

A protein is like a long string that is folded around itself in a specific way. If the protein comes unfolded or is folded in the wrong way, it may no longer be able to perform its function. When this happens, we say it has lost its biological activity. In the case of chemical reactions, you can quantitatively measure how fast the reaction occurs, and measure a quantitative biological activity (for example, to compare two proteins' ability/speed to break down a sugar).

Some laboratory techniques that measure protein cannot tell if the protein is active or not -- they can only tell if the protein is present or how much there is. Thus, you may measure that protein is present in a sample, but if the protein has been degraded in some way, you may not measure any biological activity. That's why biologists make a distinction between amount of protein and biological activity.

Hope this helps,
Burr



Click here to return to the Molecular Biology Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory