Wellner, Daniel Department of Biochemistry, Cornell University Medical College, Ithaca, New York.
Show previous versions
- Chemical structure and activity
- Classification and nomenclature
- Control of enzyme activity
- Proenzyme activation
- Feedback inhibition and enzyme repression
- Enzyme induction
- Links to Primary Literature
- Additional Readings
A catalytic protein produced by living cells. Chemical reactions involved in the digestion of foods, the biosynthesis of macromolecules, the controlled release and utilization of chemical energy, and other processes characteristic of life are all catalyzed by enzymes (Fig. 1). Hundreds of reactions can proceed simultaneously within a living cell, and the cell contains a comparable number of individual enzymes, each of which controls the rate of one or more of these reactions. In the absence of enzymes, these reactions would not take place at a significant rate. Indeed, enzymes are such efficient catalysts that they accelerate chemical reactions measurably even at concentrations too low to be detected by most protein assays. In addition, enzymes promote the chemical processes of life without being themselves altered or destroyed. See also: Catalysis and catalysts; Cell biology; Cytochemistry; Protein
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Its dedicated editorial team is led by Sagan Award winner John Rennie. Contributors include more than 9000 highly qualified scientists and 42 Nobel Prize winners.
MORE THAN 8500 articles and Research Reviews covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 17,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information