If the classe are pass/fail, then they don't show up on your GPA at all. If you do great in college algebra, nobody's going to care what your remedial grades were.
Chemistry is a LOT of math, like a lot a lot, and microbiology has a lot of chemistry in it, plus pharmacy stuff. So it's really worth going through the remedial math courses to get a really good foundation. I took three semesters of it, and it paid off immensely. I got my first 100 on a math test IN MY LIFE. I had to retake geometry in high school *and* chemistry, but I got As in both this time around.
Just study study study, do all your homework, read all the chapters the night before class. Take notes during class, then have a separate notebook to write them in neater after school (writing involves both sides of your brain so it can help you remember.) Take all the practice tests or quizzes you can find, and go to tutoring even if you think you're doing well. The secret to math is just ALL repetition. Good luck!!