The sugar moiety present in DNA molecule is:

Question

Accepted Answer

The sugar moiety present in a DNA molecule is $\beta$-D-2 deoxyribose, which is why Option 1 is the correct answer. Here is a detailed explanation:

1. **Explanation for Option 1 ($\beta$-D-2 deoxyribose):**
   - DNA, or deoxyribonucleic acid, is composed of nucleotides, each of which contains a phosphate group, a nitrogenous base, and a sugar molecule. The sugar in DNA is a five-carbon sugar known as $\beta$-D-2 deoxyribose.
   - The term "deoxy" refers to the absence of an oxygen atom at the 2' position of the ribose sugar. In ribose, the sugar found in RNA, there is an -OH (hydroxyl) group at the 2' position, whereas in deoxyribose, this is replaced by a hydrogen atom, hence the name "deoxy."
   - This structural difference is crucial for the stability and function of DNA, as the absence of the 2' hydroxyl group makes DNA less reactive and more stable than RNA, which is essential for its role in long-term genetic information storage.

2. **Explanation for why the other options are incorrect:**

- **Option 2 ($\beta$-D-ribose):**
     - $\beta$-D-ribose is the sugar found in RNA (ribonucleic acid), not DNA. RNA is similar to DNA but contains ribose instead of deoxyribose. The presence of the hydroxyl group at the 2' position in ribose makes RNA more reactive and less stable than DNA, which is why ribose is not the sugar in DNA.

- **Option 3 ($\beta$-D-Glucopyranose):**
     - $\beta$-D-Glucopyranose is a form of glucose, a six-carbon sugar, and is not involved in the structure of nucleic acids like DNA or RNA. It is commonly found in carbohydrates such as starch and cellulose, not in the genetic material of cells.

- **Option 4 ($\beta$-D-fructofuranose):**
     - $\beta$-D-fructofuranose is a form of fructose, another six-carbon sugar, and is also not part of the structure of DNA. Fructose is typically found in fruits and is a component of sucrose (table sugar), but it does not play a role in the structure of nucleic acids.

In summary, the correct sugar moiety in DNA is $\beta$-D-2 deoxyribose, making Option 1 the correct answer. The other options describe sugars that are not part of DNA's structure.