Question

answer all please

Assignment S (20 pts) Due on Friday (Nov. 22, 2019) at 9:05 AM structions: Please answer the following questions on a separate sheet of paper. Staple your answers to this cover sheet for submission. Please make sure your handwriting is legible. 196 pis) Paper is made from cellulose. What is the chemical structure of cellulose? Why does paper loose it shape and planar strength when soaked in water but not when soaked in oil? 2 pts) Using Fig. 7.2 from your text (or lecture PowerPoint), identify all epimers of D-allose. (6 pts) Consider the denaturation of DNA (going from a duplex to two single strands). This process has an unfavorable AG under standard conditions (T 298 K, pH- 7, 1M concentration). Explain the following observation in terms of the structure of DNA, noncovalent interactions, and thermodynamic parameters (free energy, enthalpy, and entropy): When the pH of an aqueous DNA solution is adjusted to 14, the DNA denatures at room temperature. 4) (6 pts) The molecule shown below is an antiviral prodrug. It is taken into the body and comverted to an active drug by phosphorylation. The active drug inhibits viral DNA replication to exert its antiviral effects. a) What natural nucleotide does the active drug mimic? b) Propose a mechanism for how the active drug inhibits viral DNA replication. NH2 NH2 N но- Active drug Prodrug

Answer 1

Question 1.

The chemical structure of cellulose can be drawn as follows.

CH,он Сң,он Hн он на н н он он Repeating cellulose unit

Paper is made up of cellulose and cellulose consists of strong hydrogen bonds that are attached to OH molecules. This is the reason why the paper is so stiff and rigid. But when water is added to paper, the hydrophilic cellulose has an affinity towards water molecules and ends up in decreasing the strength of its own hydrogen bonds. This is the reason why wet paper tears off (loses its shape and planar strength) easily. But when it comes to oil, cellulose has a very less affinity towards oil, hence even after the addition of oil, the hydrogen bonds present in the cellulose do not get disturbed.