a purified pepsin was subjected to amino acid analysis. the amino acid present in the smallest amount was lysine, C6div4N2O2 and the amount of lysine was found to be 0.431g per 100g of protein. the minimum molecular mass of the protein is?

To determine the minimum molecular mass of the protein based on the amount of lysine present, we can follow a systematic approach. First, we need to understand the relationship between the mass of lysine and the total mass of the protein. Given that lysine constitutes 0.431 grams per 100 grams of protein, we can use this information to calculate the minimum molecular mass of the protein.

Understanding the Composition

Lysine has a molecular formula of C6H14N2O2, which means it contains 6 carbon atoms, 14 hydrogen atoms, 2 nitrogen atoms, and 2 oxygen atoms. To find its molecular mass, we can sum the atomic masses of each element:

• Carbon (C): 12.01 g/mol × 6 = 72.06 g/mol
• Hydrogen (H): 1.008 g/mol × 14 = 14.112 g/mol
• Nitrogen (N): 14.01 g/mol × 2 = 28.02 g/mol
• Oxygen (O): 16.00 g/mol × 2 = 32.00 g/mol

Now, adding these together gives us the molecular mass of lysine:

Molecular mass of lysine = 72.06 + 14.112 + 28.02 + 32.00 = 146.192 g/mol

Calculating the Minimum Molecular Mass of the Protein

Next, we can use the amount of lysine present in the protein to find the minimum molecular mass of the protein. Since 0.431 grams of lysine is found in 100 grams of protein, we can set up a proportion to find out how many grams of lysine would be present in 1 gram of protein:

Amount of lysine per gram of protein = 0.431 g / 100 g = 0.00431 g/g

Now, we can calculate how many grams of protein would contain 1 gram of lysine:

Protein required for 1 g of lysine = 1 g / 0.00431 g/g ≈ 232.5 g

Finding the Minimum Molecular Mass

Now that we know that 232.5 grams of protein contains 1 gram of lysine, we can calculate the minimum molecular mass of the protein based on the molecular mass of lysine:

Minimum molecular mass of protein = 232.5 g × (146.192 g/mol / 1 g) ≈ 34,000 g/mol

This calculation indicates that the minimum molecular mass of the protein is approximately 34,000 g/mol. This value provides insight into the size and complexity of the protein, which is essential for understanding its function and behavior in biological systems.

Final Thoughts

In summary, by analyzing the amount of lysine in the protein and using its molecular mass, we can derive the minimum molecular mass of the protein itself. This process illustrates the interconnectedness of amino acids and proteins, highlighting the importance of each component in the overall structure and function of biological molecules.