Answer:
Generally, most enzymes work best at the neutral pH of 7.<u>The specificity of their functions is determine by the 3-Dimensional shape of their active sites, and this is sensitive to low or high pH of the cells</u> Enzymes are examples of globular proteins with R-groups. <u>These R-groups could have positive or negative in charges,this refers to their ionizatio</u>n.
When the pH of a cell is very low in the containing organ, the hydrogen ion concentration of the medium is high( since pH is negative log of hydrogen ion concentration,) <u>The high hydrogen ion reacts by interacting with the R-group of the enzyme altering their ionization, which weakened the ionic bonds holding the 3-D structure of the enzyme molecules in shape.</u>
The loss of 3-D arrangement disrupts the active site ,and therefore denatures the globular protein structure of enzyme. This result to failure of the enzyme to from needed enzyme-substrate-complex of enzymatic reaction.Therefore the enzyme is no longer specific, thus function is lost.
Conversely, at a very high pH of the cells, the ionization of the R-group is also affected,and the enzymes specificity of action affected. However effective buffer system always prevented these functions in pH from taken place..