Final answer:
Carboxypeptidase is the enzyme among the options that does not assist in the breakdown of carbohydrates; it is involved in protein digestion instead.
Step-by-step explanation:
The enzyme that is not involved in the breakdown of carbohydrates among the given options is carboxypeptidase. Brush border enzymes like dextrinase, glucoamylase, lactase, and sucrase assist in the hydrolysis of carbohydrates. Carboxypeptidase, on the other hand, is involved in protein digestion, not carbohydrate digestion. Therefore, the correct answer is 'e) Carboxypeptidase'.