1- All of the following are types of modifications thatcan result in an active, functional protein EXCEPT:
a. Covalent disulfide bonds between cysteine amino acids
b. Cleavage of proteins
c. Glycosylation
d. Addition of lipids to the N- or C-terminus
e. Amyloidosis
2- All of the following are reversible proteinmodifications EXCEPT:
a. Proteolysis
b. Phosphorylation
c. Acetylation
d. Methylation
e. Ubiquitination
3- How can protein-protein interactions regulateenzymes?
a. These interactions change the pH of the local environment,causing enzymes to be less efficient
b. These interactions change the conformation of the enzyme,which may inactivate the enzyme
c. These interactions change the enzyme’s amino acid sequence,which may enhance enzyme activity
d. These interactions prevent translation of the enzyme’s mRNA,leading to lower levels of the enzyme
e. These interactions send enzymes out of the cell, so that theycan no longer catalyze cellular processes
