i was wondering whether having a gap/break before a kin 1Y03/YY3 lab is necessary. otherwise i'd move a lecture immediately before the lab to free up my schedule. i know bio/chem labs require a prep period. do all labs take prep time?

Nope, there's no prep for Kin labs. It helps to read the lab beforehand so you know what you'll cover. However, there's no need for a break before it or after it for that matter .