Regulatory enzymes Allosteric enzymes:
A)are regulated primarily by covalent modification.
B)usually catalyze several different reactions within a metabolic pathway.
C)usually have more than one polypeptide chain.
D)usually have only one active site.
E)usually show strict Michaelis-Menten kinetics.
Regulatory enzymes Which of the following has not been shown to play a role in determining the specificity of protein kinases?
A)Disulfide bonds near the phosphorylation site
B)Primary sequence at phosphorylation site
C)Protein quaternary structure
D)Protein tertiary structure
E)Residues near the phosphorylation site
Regulatory enzymes How is trypsinogen converted to trypsin?
A)A protein kinase-catalyzed phosphorylation converts trypsinogen to trypsin.
B)An increase in Ca2+ concentration promotes the conversion.
C)Proteolysis of trypsinogen forms trypsin.
D)Trypsinogen dimers bind an allosteric modulator,cAMP,causing dissociation into active trypsin monomers.
E)Two inactive trypsinogen dimers pair to form an active trypsin tetramer.
Regulatory enzymes The allosteric enzyme ATCase is regulated by CTP,which binds to the T-state of ATCase.CTP is a: