Changing environmental conditions, such as temperature or PH, can effect enzyme shape how would this alter the enzymes function?

Raising the temperature will denature an enzyme so that it is no longer functional. Lowering the temperature will reduce the rate of the reaction so low as to make it seem non-functional. Altering the pH above or below its optimum pH will also reduce the enzyme's activity, and at extremes the enzyme may be permanently denatured.