Apples, like all living organisms, contain many different enzymes. However, eating fresh apples -- with or without their skins -- doesn't provide you with enzymes that benefit your health. Although apples contain many healthy components, you neither need nor can you utilize the enzymes in fresh apples.
Enzymes are large proteins that participate in biochemical reactions, helping to regulate and speed reactions that take place in living organisms, without being changed themselves, explain Mary Campbell and Shawn Farrell in their book "Biochemistry." Your cells depend upon many different types of enzymes to maintain function. For instance, you secrete digestive enzymes into your gastrointestinal tract to help you break down food. Your cells also produce many enzymes that work together to help cells communicate with one another, generate energy and engage in a wide variety of functions.
All living cells contain enzymes; apple cells are no exception. When you eat an apple, you ingest the cells comprising the apple and therefore ingest the enzymes. However, there's no scientific evidence to suggest that the enzymes in a fresh apple have any effect whatsoever upon your body. Apple enzymes participate in apple-related reactions, and enzymes are very specific with regard to function, explain Reginald Garrett and Charles Grisham in their book "Biochemistry." This means you can't anticipate that an apple enzyme will have activity in a human.
Another important consideration with regard to the enzymes you consume in food is that your stomach is very acidic. Enzymes are quite sensitive to acid; only very few, and none of those found in apples, are able to withstand strongly acidic environments. When you eat an apple, the acid in your stomach reacts with the enzymes in the apple and denatures them so they no longer function as they once did. You then digest them like any other dietary protein.
Generally speaking, humans don't need supplemental enzymes. Your digestive tract produces all the enzymes you need to break down your food; digestive enzyme deficiencies are rare, although lactose intolerance is an exception. As for the enzymes your cells use outside the digestive tract, there's no evidence to suggest that you can get enzymes out of the stomach or intestine and into the cells, rendering the enzymes in your food essentially useless except as a source of energy, like any other dietary protein.