I used KhanAcademy and I thought it was sufficient. The MCAT will only test you on how to apply the basics, so I believe KhanAcademy should suffice for those topics that you are a little rusty on.
In my opinion it would be tough to find a recorded lecture for Molecular Bio online. If you want more detail just open up a book, I'd either go with TBR Bio II or a Molecular Bio Text book. I am using the TBR book ans its super detailed, its perfect.
Try the University of Berkley Podcast. They have recorded lectures on cell bio and I think tons of molecular bio topics are covered. Also, I would know all the major biology lab techniques, as they are pretty high yield for the MCAT (western and southern blotting, PCR, in-situ-hybridization, etc.)
heres the link for the MCB (molecular and cell biology) podcasts at Berkley