Government scientistscontinue to study the bodies of the aliens whose spacecraft
ID: 5380 • Letter: G
Question
Government scientistscontinue to study the bodies of the aliens whose spacecraft crashedin Roswell, NM in 1947. Among other things, the scientists haveinvestigated the structure of the genetic material isolated fromthe aliens’ cells. This material is similar in some ways toDNA in its chemical makeup. It contains in abundance the 4-carbonsugar erythrose and a molar equivalent of phosphate groups.Additionally, it contains six nitrogenous bases: adenine (A),guanine (G), cytosine (C), uracil (U), inosine (I), and2-thiouracil (S2U).These bases exist in the following proportions:
(C + U +S2U) = (A + G +I)
U = G S2U = A C = I
X-ray diffraction studieshave established a regularity to the molecule and a constantdiameter of
a. Based on the data described above, propose ageneral structural model for this molecule. Describe itbriefly.
b. What base-pairingproperties must exist for each of the bases in thismodel?
c. Is 2-thiouracil apurine or a pyrimidine?
d. Is inosine a purine or apyrimidine?
Explanation / Answer
i'm leaning towards a triple- helix structure because of thenumber of nitrogenous bases and the way the proportions addup. Uracil and Inosine would have be able to base pair with oneother base while the rest can base pair with 2 different bases andbe in the center. inosine is a purine and -thiouracil is a pyramidine. the base pairing goes something like this: U A U I S2U I U G G I C I at least that way the proportions seem to work out. then again, i might have no idea what i'mdoing!Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.