When a new response is submitted via the File Upload Form, the data is saved in a Google Spreadsheet while the files are saved in your Google Drive. The first row is the header containing the question titles while the other rows are answers, one row per response.
Later, if you edit the form design and add, edit or update form fields, the header row of the Google Spreadsheet will be updated as well.
However, as you may notice, the order of columns in the Google spreadsheet may not be the same as the order in your Google Form. If this is an issue, you can manually move the entire columns to the correct position in the spreadsheet.
When a new response is received, the data will automatically go into the right columns.