Staphylococcus nuclease is an enzyme that catalyzes the hydrolysis of DNA.The reaction is catalyzed by Ca2+, Glu 43, and Arg 87. Explain how the metal catalyst facilitates this reaction. Recall that the nucleotides in DNA havephosphodiester linkages.

92.11

Progesterone is a female hormone that plays a critical role in the menstrual cycle by preparing the lining of the uterus for implantation of an egg. During W. S. Johnson's biomimetic synthesis of progesterone (a synthesis that draws inspiration from and mimics naturally occurring, biosynthetic pathways), one of the final reactions in the synthesis was believed to have proceeded via the following intermediate. Use resonance structures to explain why this intermediate is particularly stable. (J. Am. Chem. Soc. 1971, 93,4332-4334). SHAR

A researcher creates random copolymers of three nucleotides each by mixing polynucleotide phosphorylase with guanine and adenine nucleotides in a ratio of 5 guanine nucleotides to 1 adenine. Give the different copolymers produced and their theoretical proportions.

Please Provide the name of the following nitrogen-containing heterocyclic base for both of the following

Radioactive uracil can be used to label all the pyrimidine residues in DNA. Explain how this occurs, thinking about pyrimidine synthetic pathways.

Why Ranitidine is better than Cimetidine ? Please explain at your own words.

Write a DNA sequence that would encode the amino acid sequence valyl-tryptophanyl-lysyl-prolyl-phenylalanyl-threonine.

With the aid of the simple generic diagram, identify and explain how the type of chemical bonding stabilizes a secondary structure present in 3GRS (glutathione reductase).

2.7 Now that you have figured out the reaction mechanism, let's explore the action mechanism of the following drug. Notice that this molecule is composed of two chloroethylamine groups and therefore can react with two different nucleophiles. Complete the following reaction mechanism. R-N Cl CL + R'-NH₂ R"-NH₂ The above reaction is responsible for the activity of the drug. Because of its ability to react with two nucleophiles, the drug can create a bridge between two biologically active molecules and disrupt their activity. This process is known as 'cross-linking'. For example, it can react with two DNA strands and prevent their separation during replication. This will cause cytotoxicity and cell death. 2.8 Draw a scheme/cartoon to represent the general idea of chemical cross-linking described above.