IIT JEE , AIEEE Forum - Chemistry , Physical Chemistry

shannyc

In detail how does pH effects amylase activity and explain the value of the zero time control

dev_22oct

The enzyme used in this lab exercise is amylase, which is commonly found in saliva and germinating seeds. It catalyzes the breakdown of starch. When amylase reacts with starch, it cuts off the disaccharide maltose (two glucose molecules linked together). As the reaction progresses, less starch will be present and more sugar (maltose) will be present. In lab, the activity of amylase was observed by using iodine. Remember, iodine reacts with starch to form a dark brown/purple color. As amylase breaks down starch, less and less starch will be present and the color of the solution (if iodine is added) will become lighter and lighter. The color change was observed using spot-plates as illustrated on the diagram below.

dev_22oct

Effects of pH

Enzymes are affected by changes in pH. The most favorable pH value - the point where the enzyme is most active - is known as the optimum pH. This is graphically illustrated in Figure 14.

Extremely high or low pH values generally result in complete loss of activity for most enzymes. pH is also a factor in the stability of enzymes. As with activity, for each enzyme there is also a region of pH optimal stability.

dev_22oct

a control is a standard condition which includes all the factor thought to be significant, except one, so that details of its effect may be discovered by comparison.

krishna.gopal

Good answer dev. well done.

drish

YEAH ITS VERY GOOD!!!!!!!!!!!!

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Effects of pH