On the online TurboTax edition for self-employed workers, I could not locate where I could enter itemized expenses. I added them up and actually had difficulty locating where I could enter this cumulative amount.
I am slightly disappointed that it was not more obvious.
In TurboTax you are only required to put the totals for your different types of expenses. The actual T2125 form also only requires totals as well. If the CRA needs more information about a particular expense, they will request that information from you.