Molecules to Metabolism in 8m from Dan Rott:
Or you could watch Intro to Molecular Biology from Alex Lee, or many assessment statements are covered by Stephanie Castle.
Interactive Metabolic Pathways Map: the latest edition of the iconic IUBMB-Sigma-Nicholson Metabolic Pathways Chart and here are other IUBMB Nicholson Minimaps.
In Crash Course Biology #1 – ‘that’s why Carbon is a Tramp’, Hank introduces us to the chemistry of life:
What’s in a molecule? – The science of macaroni salad from TED-Ed (3m 15s).