Chapter 8

Last update by mayur on 03/27/2014
982321 People have viewed this Quiz
  • Share

Which of the following statements describes enzyme cooperativity?

A) A multi-enzyme complex contains all the enzymes of a metabolic pathway.

B) A product of a pathway serves as a competitive inhibitor of an early enzyme in the pathway.

C) A substrate molecule bound to an active site affects the active site of several subunits.

D) Several substrate molecules can be catalyzed by the same enzyme.

E) A substrate binds to an active site and inhibits cooperation between enzymes in a pathway.



Answer:

C) A substrate molecule bound to an active site affects the active site of several subunits.



View Chapter 8 as Flashcard Deck

Related Quiz Content
  • feldman2009
    Answered in Chapter 8

    Some enzymatic regulation is allosteric. In such cases, which of the following would usually be found? 

    A) cooperativity 

    B) feedback inhibition 

    C) both activating and inhibitoryactivity 

    D) an enzyme with more than one subunit 

    E) the need for cofactors 



    D) an enzyme with more than one subunit 



  • feldman2009
    Answered in Chapter 8

    Which of the following is an example of cooperativity? 

    A) the binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway 

    B) protein function at one site affected by binding at another of its active sites 

    C) a molecule binding at one unit of a tetramer allowing faster binding at each of the other three 

    D) the effect of increasing temperature on the rate of an enzymatic reaction 

    E) binding of an ATP molecule along with one of the substrate molecules in an active site 



    C) a molecule binding at one unit of a tetramer allowing faster binding at each of the other three 



  • feldman2009
    Answered in Chapter 8

    Among enzymes, kinases catalyze phosphorylation, while phosphatases catalyze removal of phosphate(s). A cell's use of these enzymes can therefore function as an on-off switch for various processes. Which of the following is probably involved? 

    A) the change in a protein's charge leading to a conformational change 

    B) the change in a protein's charge leading to cleavage 

    C) a change in the optimal pH at which a reaction will occur 

    D) a change in the optimal temperature at which a reaction will occur 

    E) the excision of one or more peptides 



    A) the change in a protein's charge leading to a conformational change 



  • feldman2009
    Answered in Chapter 8

    Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity? 

    A) cessation of all enzyme formation 

    B) compartmentalization of enzymes into defined organelles 

    C) exporting enzymes out of the cell 

    D) connecting enzymes into large aggregates 

    E) hydrophobic interactions 



    B) compartmentalization of enzymes into defined organelles 



  • feldman2009
    Answered in Chapter 8

    An important group of peripheral membrane proteins are enzymes, such as the 

    phospholipases that attack the head groups of phospholipids leading to the degradation of damaged membranes. What properties must these enzymes exhibit? 

    A) resistance to degradation 

    B) independence from cofactor interaction 

    C) water solubility 

    D) lipid solubility 

    E) membrane spanning domains

    C) water solubility 



  • feldman2009
    Answered in Chapter 8

    Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as 

    __________ is to __________. 

    A) exergonic; spontaneous 

    B) exergonic; endergonic 

    C) free energy; entropy 

    D) work; energy 

    E) entropy; enthalpy 

    B) exergonic; endergonic 



  • feldman2009
    Answered in Chapter 8

    Most cells cannot harness heat to perform work because 

    A) heat is not a form of energy. 

    B) cells do not have much heat; they are relatively cool. 

    C) temperature is usually uniform throughout a cell. 

    D) heat can never be used to do work. 

    E) heat denatures enzymes. 



    C) temperature is usually uniform throughout a cell. 



  • feldman2009
    Answered in Chapter 8

    If an enzyme is added to a solution where its substrate and product are in equilibrium, what would occur?

    A) Additional product would be formed.

    B) Additional substrate would be formed.

    C) The reaction would change from endergonic to exergonic.

    D) The free energy of the system would change.

    E) Nothing; the reaction would stay at equilibrium.



    E) Nothing; the reaction would stay at equilibrium.