Human ribonucleotide reductase has two allosteric sites, the S site and the A site. What is the function of each? How does this compare with the E. Coli enzyme discussed in the text?

What type of protein structure does the active form of Catechol-oxidase most likely possess?

In studies using repeating copolymers, AC . . . incorporates threonine and histidine, and CAACAA . . . incorporates glutamine, asparagine, and threonine. What triplet code can definitely be assigned to threonine?

The biosynthetic pathway for the two amino acides E and H is shown schematically in the Figure below: A W E 2 Z H How would this pathway change if C was mutated and non-functional?

Treating a solution of ribonuclease with 2-mercaptoethanol and urea denatures the enzyme. If the 2-mercaptoethanol is removed, followed by the removal of urea, the ability of the enzyme solution to hydrolyse RNA is reduced by about 99%. What is the most plausible explanation for this observation?   a. All of the RNase molecules have about 1% of their usual activity, due to changes to the organisation of disulphide bonds   b. Random formation of disulphide bonds mean about 1% of the RNase molecules are 100% active whereas 99% have no activity   c. Deprotonation of histidine in the active site of the enzyme means that only about 1% of the enzyme molecules are active   d. Deprotonation of histidine in the active site of the enzyme means that all of the enzyme molecules have 1% of their usual activity

Given the following diagram of how protein AWESOME1 binds to it's target DNA, describe the potential effects of each of the 5 mutations shown below. The wild-type sequence of a helix #1 is also shown in the blue box, and all the mutations are in helix #1 (see numbers for identifying particular residues). a helix #1 R(1)-V-I-L-Y-F-W-I-M-Y-F-S-H-Y-W-R(16) #1 Predict the consequence of the following mutations: 1) Arg(1) to Glu 2) Arg(1) to Ala 3) Phe(6) to lle 4) Trp(7) to Phe 5) Met(9) to Pro in