Concept explainers
To explain: The reason why the degradation of protein by proteosomes requires ATP.
Concept introduction:
Proteolysis has the enzymes proteases that catalyze the breakdown of the proteins into smaller amino acids or polypeptides. It is an exergonic process which involves a positive energy flow from the system to the surroundings.
Explanation of Solution
Explanation:
ATP is the energy currency of the cell which can be renewed. In a cell when catabolism occurs, the energy is released. Ubiquitin functions to target the proteins for the protein degradation by using the proteosomes. This process is catalyzed by utilizing mainly three enzymes- ubiquitin-activating enzymes, ubiquitin-conjugating enzymes and ubiquitin-protein ligase.
Even though the proteolysis is an exergonic process, the proteosomes requires ATP for the protein degradation by linking to the ubiquitin covalently. This is due to the following reasons:
- For the first step of protein ubiquitination reactions, ATP is utilized in order to activate the ubiquitin for linking them to the target protein with the help of ubiquitin-activating enzymes.
- Also, the ATP is utilized for the protein denaturation as it goes into the proteosomes.
Want to see more full solutions like this?
Chapter 21 Solutions
Biochemistry 410/411 Textbook - 5th Edition - Custom Texas A&M University
- BiochemistryBiochemistryISBN:9781319114671Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.Publisher:W. H. FreemanLehninger Principles of BiochemistryBiochemistryISBN:9781464126116Author:David L. Nelson, Michael M. CoxPublisher:W. H. FreemanFundamentals of Biochemistry: Life at the Molecul...BiochemistryISBN:9781118918401Author:Donald Voet, Judith G. Voet, Charlotte W. PrattPublisher:WILEY
- BiochemistryBiochemistryISBN:9781305961135Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougalPublisher:Cengage LearningBiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage LearningFundamentals of General, Organic, and Biological ...BiochemistryISBN:9780134015187Author:John E. McMurry, David S. Ballantine, Carl A. Hoeger, Virginia E. PetersonPublisher:PEARSON