Histidine Buffer Calculator
welcome to histidine buffer calculator, histidine buffer calculator allows you find the histidine buffer solution in fews steps. Enter the desire volume of buffer solution you want to make in letter, enter the concentration in mM and desire pH. click on calculate button and hence succesfully calculated the histidine buffer solution.
What is Histidine?
Histidine is an essential amino acid that plays a crucial role in protein structure and function. It has an imidazole side chain, making it a versatile component in enzyme active sites and metal ion binding sites. The chemical formula for histidine is C6H9N3O2.
What is a Histidine Buffer?
A histidine buffer is a solution that uses histidine and its conjugate acid/base forms to maintain a stable pH. This buffer is effective in maintaining the pH range where histidine can effectively donate and accept protons, typically around the pKa values of its ionizable groups. It is very important in biological and chemical reactions involving protein and amino acid. The histidine buffer calculator helps you precisely calculate the buffer solution based on the given formula..
Formula to Calculate Histidine Buffer
The Henderson-Hasselbalch equation is used to calculate the pH of a histidine buffer:
pH = pKa + log([Base form]/[Acid form])
For histidine, the relevant pKa values are approximately 1.8, 6.0, and 9.2, corresponding to the carboxyl group, the imidazole side chain, and the amino group, respectively.
Why is Histidine a Good Buffer?
- It has a pKa around 6.0, which is close to the physiological pH of 7.4, making it effective in biological systems.
- The imidazole side chain can participate in proton transfer reactions, allowing it to stabilize pH changes.
pH Values Where Histidine Serves as a Good Buffer
Histidine serves as a good buffer in the pH range of approximately 5.5 to 7.5, centered around the pKa of its imidazole side chain (pKa ≈ 6.0).
Why Histidine Acts as a Buffer
Histidine acts as a buffer because of its ability to accept and donate protons via its imidazole side chain, which has a pKa close to physiological pH. This allows histidine to stabilize pH changes in the solution.
Histidine Buffer Range and Preparation
The effective buffering range of histidine is approximately pH 5.5 to 7.5.
Histidine Buffer Preparation Tables
10 mM Histidine Buffer Preparation
- Dissolve histidine in water to achieve a final concentration of 10 mM.
- Adjust the pH to the desired value using HCl or NaOH.
- Dilute to the final volume with water.
Example Calculation:
- Desired volume: 1 L
- Desired concentration: 10 mM
Calculate the required amount of histidine:
Molecular weight of histidine = 155.16 g/mol Amount of histidine = 10 mM × 155.16 g/mol × 1 L = 1.5516 g
- Weigh out 1.5516 g of histidine and dissolve in approximately 900 mL of water.
- Adjust the pH using HCl or NaOH.
- Dilute to 1 L with water.
20 mM Histidine Buffer Preparation
- Dissolve histidine in water to achieve a final concentration of 20 mM.
- Adjust the pH to the desired value using HCl or NaOH.
- Dilute to the final volume with water.
Example Calculation:
- Desired volume: 1 L
- Desired concentration: 20 mM
Calculate the required amount of histidine:
Molecular weight of histidine = 155.16 g/mol Amount of histidine = 20 mM × 155.16 g/mol × 1 L = 3.1032 g
- Weigh out 3.1032 g of histidine and dissolve in approximately 900 mL of water.
- Adjust the pH using HCl or NaOH.
- Dilute to 1 L with water.
Summary of Preparation Steps
- Weigh out the appropriate amount of histidine based on the desired molarity.
- Dissolve histidine in a volume of water less than the final desired volume.
- Adjust the pH to the target value using HCl or NaOH.
- Add water to reach the final volume.
By following these steps, you can prepare histidine buffers of various concentrations and pH values suitable for your experimental needs.