pH Stability and Buffer Systems in Biological Proteins

Mr. Andersen explains the importance of pH and buffers in maintaining stability in biological systems, particularly in blood. He discusses how buffer solutions work, the role of weak acids and conjugate bases, and the significance of equilibrium and pKa in buffer capacity. The video also covers Le Chatelier's Principle and its application in buffer solutions, as well as the biological importance of buffers in proteins and amino acids.

Why is it crucial for proteins in our blood to maintain a specific pH range?

• To make them more reactive

• To allow them to dissolve in blood

• To ensure they can carry oxygen and carbon dioxide effectively

• To prevent them from becoming too acidic

What happens when more protons are added to a buffer solution?

• The pH increases significantly

• The reaction shifts to the left

• The solution becomes more basic

• The buffer capacity decreases

Which factor is crucial for maintaining a stable pH in a buffer solution?

• High concentration of water

• High temperature

• Equal concentrations of weak acid and conjugate base

• Low pressure

What is the role of the equilibrium constant (pKa) in buffer solutions?

• It decreases the buffer's effectiveness

• It determines the color of the solution

• It helps in maintaining the pH close to the pKa value

• It increases the solubility of the buffer

How does adding a strong base affect a buffer solution?

• It shifts the reaction to the left

• It decreases the pH

• It increases the concentration of hydronium ions

• It shifts the reaction to the right

What happens to the pH if the concentration of the weak acid is much larger than its conjugate base?

• The buffer capacity increases

• The pH increases

• The pH decreases

• The pH remains constant

In a buffer solution, what does a pH value less than the pKa indicate?

• The buffer is ineffective

• More weak acid is present

• More base is present

• The solution is neutral

What color does Bromothymol blue turn in a neutral solution?

• Green

• Red

• Yellow

• Blue

Why is pH important for protein function in biological systems?

• It makes proteins more acidic

• It changes the behavior of amino acid side chains

• It increases protein size

• It affects the solubility of proteins

What is a key characteristic of a good buffer solution?

• High pressure

• Low temperature

• Equal pH and pKa values

• High concentration of water