Mitochondria
Advanced companion to Meet the Cell Squad, sung directly about mitochondria: double-membrane organelles whose folded inner membrane (cristae) hosts the electron transport chain, producing roughly thirty ATP per glucose, carrying their own circular DNA inherited only from the mother, and descended from free-living bacteria engulfed roughly two billion years ago. Structured as an escalating count of folds, protons, and ATP.
One fold in my inner membrane makes one crista, more surface for the work, Two membranes wrap around me, an outer wall and a folded inner one, Add the Krebs cycle turning twice for every glucose that arrives, Three carbon dioxide molecules escape for every pyruvate broken down inside.
Count the electrons riding down my electron transport chain in single file, Four protein complexes pass them along, pumping hydrogen ions out the door, Ten protons cross for every pair of electrons pushed along that chain, Around thirty ATP molecules can rise from one whole glucose by the time I'm done.
A muscle cell holds a few hundred of me, a liver cell holds a thousand more, A heart cell packs in even more, beating nonstop, needing power to spare, Count my own circle of DNA, separate from the nucleus, passed down only from your mother, About two billion years ago I was a free bacterium, swallowed whole and never let go.
Fold by fold, proton by proton, ATP by ATP, the count keeps climbing higher, One glucose in, around thirty ATP out, the numbers add up fast, I'm mitochondria, the powerhouse, born from a bacterium billions of years back, Counting energy out for every cell that needs the fire, generation after generation.
Advanced companion to: Meet the Cell Squad (Mito), sung about the real cell biology directly rather than through character persona.
Key Concepts: Mitochondria have two membranes; the inner membrane folds into cristae, increasing surface area for the electron transport chain | The Krebs cycle and electron transport chain together yield roughly thirty ATP molecules per glucose | Mitochondria carry their own small circular DNA, inherited only from the mother | Endosymbiotic theory: mitochondria descend from free-living bacteria engulfed by an ancestral cell roughly two billion years ago | Cells with high energy demands (muscle, liver, heart) contain far more mitochondria than low-demand cells
Key Words: mitochondria, cristae, electron transport chain, ATP, mitochondrial DNA, endosymbiotic theory