would agree with above poster and altho i made a post about this on another thread, i was obviously not clear enuff. so i hope it reads as i mean it to with this post.
depending on institution and their entry requirements, it's always wise to ask what u will need to ensure u can deliver and don't fall short come selection time.
access can be perfectly fine on its own with their level 2 maths/english components being seen as acceptable. then again, it may not be enuff.
posts here seem to suggest that the science based degrees can be more demanding and may well ask for an access as well as maths GCSE (or more, such as an A level) done separately and alongside...etc etc
best bet is, check with admissions to all the places u wanna apply to.
Edit** and to add that this does of course apply to access courses that DO have it as a requirement to do maths/english (ie, u don't pass unless u have both maths and english, whether thru prior study or thru the access)) and NOT those courses that don't have level 2 maths and english attached.