Ochem is looked heavily upon my adcoms because it is most challenging couse in the prereq's, at least according to my premed advisor.
If you have enough time to might want to take it again, but if you do make sure you get an A. However, if you are science major and will be taking more difficult courses such as Biochem you probably don't need to take it again if you do well in more advanced science courses.
Good Luck.