I know y'all were dying for some more metabolic diagrams. Honestly, this dry erase board thing is working out pretty danged well. And then snapping a digital photo preserves it for later studying after I wipe it clean. I suppose I could use software for it but for a non-digital native that can remember when computers first came out (they used cassette tapes!), I prefer the feel of the pen in my hand.
Here's glycolysis in all its glory. 10 simple steps and you convert Glucose to Pyruvate without any oxygen. It drives the brain and red blood cells as that's pretty much it for them as far as fuel goes. Skeletal muscle can use both depending on the fiber type (fast twitch use glucose as it's faster and doesn't need oxygen, slow twitch use fat as it lasts longer). Cardiac muscle on the other hand uses more fat (70%ish fat vs 30%ish glucose if my memory from my research days holds true)