GRE Subject Test: Biology : Understanding Protein and Enzyme Function
Study concepts, example questions & explanations for GRE Subject Test: Biology
All GRE Subject Test: Biology Resources
Example Questions
Example Question #11 : Understanding Protein And Enzyme Function
The activity of certain enzymes can be modulated via effector binding to __________ sites; regulation at these sites often results in a conformational changes that alters the activity level of the enzyme either positively or negatively without the effector binding to the active site.
competitive
active
allosteric
inhibitory
kinase
allosteric
The definition of allosteric enzyme regulation is that a cofactor or molecule binds and interacts with a site on the enzyme other than the active site. This often changes something about the shape of the enzyme which changes something about its interaction with its substrate, thus modulating how active the enzyme is.
Example Question #12 : Understanding Protein And Enzyme Function
I. Cytochrome c oxidase, an important enzyme in the electron transport chain, uses copper ions as cofactors.
II. Cofactors are always metal ions, such as iron and copper.
III. An enzyme will have a binding site specific for one type of cofactor.
IV. Some cofactors can be formed from vitamins C, B12, and K, and these cofactors then serve to facilitate electron transport in many biological processes.
I and IV
I, III, and IV
I only
I, II, and III
II and III
I and IV
Cofactors are not always metal ions, nor are enzymes limited to interactions with a single cofactor. Cofactors can be metal ions, but they can also be organic molecules, and an enzyme may be able to bind and be altered by many of them. The other two statements are true.
Certified Tutor
Certified Tutor
All GRE Subject Test: Biology Resources
