How many of the following compound contain sulphur atom? Pyrrole, Furan, Thiophene, Cysteine, Tyrosine, Pyridine

The correct answer is 2.

To determine how many of the given compounds contain a sulfur atom, let us analyze the chemical structure and composition of each compound listed in the question:

1. Pyrrole: A five-membered aromatic heterocycle containing four carbon atoms and one nitrogen atom (${\text{C}}_4{\text{H}}_5\text{N}$). It does not contain sulfur.

2. Furan: A five-membered aromatic heterocycle containing four carbon atoms and one oxygen atom (${\text{C}}_4{\text{H}}_4\text{O}$). It does not contain sulfur.

3. Thiophene: A five-membered aromatic heterocycle containing four carbon atoms and one sulfur atom (${\text{C}}_4{\text{H}}_4\text{S}$). Contains sulfur.

4. Cysteine: A sulfur-containing amino acid with the chemical formula $\text{HOOC-CH(NH}{2}_{}\text{)-CH}{2}_{}\text{-SH}$. Contains sulfur.

5. Tyrosine: An aromatic amino acid with a side chain containing a para-hydroxybenzyl group (${\text{C}}_9{\text{H}}_{11}{\text{NO}}_3$). It does not contain sulfur.

6. Pyridine: A six-membered aromatic heterocycle containing five carbon atoms and one nitrogen atom (${\text{C}}_5{\text{H}}_5\text{N}$). It does not contain sulfur.

Out of the six compounds, exactly 2 compounds (Thiophene and Cysteine) contain a sulfur atom.