When you take cells or tissue pieces and grind them with an acid in a mortar and pestle, all the small biomolecules dissolve in the acid. Proteins, polysaccharides and nucleic acids are insoluble in mineral acid and get precipitated. The acid soluble compounds include amino acids, nucleosides, small sugars etc. When one adds a phosphate group to a nucleoside one gets another acid soluble biomolecule called

Options

A. Nitrogen base
B. Adenine
C. Sugar phosphate
D. Nucleotide

Answer

To solve the question, we need to understand the relationship between nucleosides and nucleotides. Here’s a step-by-step breakdown:

### Step 1: Understanding Nucleosides
- A nucleoside is composed of two main components: a nitrogenous base (which can be adenine, guanine, thymine, cytosine, or uracil) and a sugar molecule (which can be ribose for RNA or deoxyribose for DNA).

### Step 2: Adding a Phosphate Group
- When a phosphate group is added to a nucleoside, it modifies the structure of the nucleoside. The phosphate group is a key component that distinguishes nucleotides from nucleosides.

### Step 3: Defining Nucleotides
- A nucleotide is defined as a nucleoside with an attached phosphate group. Therefore, when you add a phosphate group to a nucleoside, you form a nucleotide.

### Step 4: Characteristics of Nucleotides
- Nucleotides are acid-soluble biomolecules and play a crucial role in the formation of nucleic acids (DNA and RNA). They consist of the nitrogenous base, the sugar, and the phosphate group.

### Conclusion
- Thus, when one adds a phosphate group to a nucleoside, the resulting acid-soluble biomolecule is called a **nucleotide**.

---