Carboxypeptidase, which sequentially removes carboxyl-terminal amino acid residues from its peptide substrates, is a single polypeptide of 307 amino acids. The two essential catalytic groups in the active site arefurnished by Arg 145 and Glu 270 .(a) If the carboxypeptidase chain were a perfect α helix, how far apart (in Å) would Arg 145 and Glu 270 be? (b) Explain how the two amino acid residues can catalyze a reaction occurring in the space of a few angstroms

Aside from asymmetric hydrogenation (Section 29.4), various more strategies for the production of optically active amino acids are currently accessible. How may a process like the Strecker synthesis be modified to produce chiral amino acids?

Which of the following statements comparing the synthesis of pyrimidines vs. purines is correct? (A) Both types of nucleotides are formed by constructing the nitrogenous base step-by-step on a phosphorylated ribose foundation.(B) Aspartate serves as a nitrogen donor only for purines, while pyrimidines use only glutamine as a nitrogen donor. (C) Both pathways require the synthesis of 5-phophoribosyl-1-pyrophosphate.(D) During the de novo synthesis of both types of nucleotides, nucleosides are formed first and then phosphates are added to the 5’ carbon of ribose.(E) Ribonucleotide reductase is used to form dNTPs from pyrimidine NTPs but not purines.

What is the first thing that must occur in order for the catalysis of the peptide bond to begin. What is a specificity pocket? What are the preferences of chymotrypsin due to its specificity pocket?

1. A) Explain this statement, “Most enzymes are gene-encoded proteins, but most enzymes are not only protein". B) You recently isolated a new enzyme in your lab, and you named it "lipidase 1120". As a temporary name, this is fine. Who is responsible for assigning a formal name, and on what criteria will that name be assigned?

6) Proteins can be modified by phosphorylation, which adds a phosphate group to the hydroxyl group of serine, threonine, or tyrosine residues. The R-group for phosphoserine is shown at right. A) The image below is an Isoelectric focusing strip that shows the unphosphorylated protein-of-interest (in blue). To which side of the unphosphorylated protein would you expect to see the phosphorylated protein? (Draw an arrow to indicate direction). Briefly justify your answer. un-phosphorylatable: Low pH Justify: B) To study the effects of phosphorylation, researchers often mutate a Ser/Thr to appear as though it is always phosphorylated or never phosphorylated at a particular site. What amino acid substitution should you use to preserve similar dimensions as Ser (or Thr) but make the side chain appear to be: constitutively (always) phosphorylated: Justify: Ser or Thr → O O=P-O O I CH₂ Ser or Thr➜ Phosphoserine High pH

A family of proteins known as cupredoxins contain a single redoxactive Cu ion coordinated by a Cys, a Met, and two His residues. The reduction potentials of cupredoxins range from about 0.15 V to 0.68 V. What does this information reveal about the role of the protein component of the cupredoxins?

The catalytic triad consists of Asp, His, and Ser. What would be an alternative for histidine and how would we draw the interactions in a mechanism?

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?

Can you please describe the specific components that each of these structures are comprised of ( alpha helices and beta sheets) in more detail? Also, what do the different colors represent?  Your reply will be greatly appreciated.  The ligand that was assigned to me is tadalafil.