You can use this guide to get started with your research for your enzyme research paper. 

In your report, you'll need to include citations to studies that support your writing, whether by providing contextual background for your hypothesis, or strengthening your interpretation of your results. You'll mostly be searching for primary literature to cite in your report, but secondary literature such as review articles can be helpful, too! Review articles can be helpful for that background information, and can also be a great source for you to find the relevant primary literature. 

It's helpful to keep in mind the differences between a primary article (presents original research findings; will almost always therefore have a 'methods' and a 'results' section) and a review article (provides an overview of already published research, and no new data; will typically not have a 'methods' or 'results' section; will often have the word "review' in the title of the article or journal). Take a look at the two articles linked below and see if you can quickly determine which is a primary article and which is a review article.