Newsdate: March 1, 2030. A unique creature has been discovered du...

Question

Newsdate: March 1, 2030. A unique creature has been discovered during exploration of outer space. Recently, its genetic material has been isolated and analyzed. This material is similar in some ways to DNA in its chemical makeup. It contains in abundance the 4-carbon sugar erythrose and a molar equivalent of phosphate groups. In addition, it contains six nitrogenous bases: adenine (A), guanine (G), thymine (T), cytosine (C), hypoxanthine (H), and xanthine (X). These bases exist in the following relative proportions:

A =T = H and C = G = X

X-ray diffraction studies have established a regularity in the molecule and a constant diameter of about 30 Å. Together, these data have suggested a model for the structure of this molecule.

Propose a general model of this molecule. Describe it briefly.

Accepted Answer

Hi everyone. Let's look at our next question. It says using chroma to graphic methods. Irwin charge off at his colleagues separated the four bases in DNA samples obtained from various organisms. They found out that the amount of adenine residues is proportional to blank residues and the amount of guanine residues is proportional to blank residues. Well luckily this is a pretty straightforward easy question for us. Um We know that the amount of adenine residues since we know what adnan pairs with adenine pairs with timing. So the amount of adding residues he found was proportional to timing residues. So let's look at our answer choices and we see only choice C. Has timing first. So again if time was of the essence on a test I'd go ahead and select choice C. Um That will just walk through this a little more thoroughly. Um Then we say the amount of guanine residues is proportional to and of course guanine pairs with cytosine and therefore charge A. Found the amount of guanine residues was proportional to the amount of cytosine residues. So we see that's indeed correct in choice C. When we look at our other answer choices, um choice A. Has cited even timing but in the wrong order that's why that's not correct. Choice B has uracil in it as does choice see uracil is the base found in RNA instead of timing so you wouldn't find yourself and D. N. A. So that rules out those two. And again that was important because it later led to be that key a key element in the discovery of the structure of D. N. A. When it was seen that those bases were always found in proportional amounts, Leading to that discovery that they were always paired in that double helix later on, of course, but Charge A. Found that the amount of adnan residues are proportional to choice c thiamine residues and the amount of guanine residues is proportional to cytosine residues. See you in the next video.

Key Concepts

Nucleic Acid Structure

Base Pairing Rules

Molecular Structure and X-ray Diffraction

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