Yes, you may access the Business Expenses section in one of two ways:
First, log into TurboTax and open your return. You should see "Personal Info" in the TurboTax header.
1) Go to My Account >> Tools >> Topic Search. Type in "schedule c", click the topic in the list, then click "GO". Continue with Step 3 below.
2) Click the Business tab, Business Income & Expenses, and "I'll choose what I work on." Click Update beside Business Income and Expenses.
3) Click Edit beside the business you wish to work on.
4) Scroll down to Business Expenses and click Update beside Other Common Business Expenses.
Most taxpayers choose to enter major purchases under $2,500 as Other Miscellaneous Expenses with a custom category (see screenshot below - click to enlarge).