“The acetyl-CoA enters the Krebs cycle, which takes place in the matrix of the mitochondrion in eukaryotic cells,” I read aloud, and then paused, trying to wrap my mind around what I had just read. “Oh, right, mitochondrion. That’s the power producing organelle thingy, isn’t it.” “Yes,” said my teenaged son, from the quicksand of his own fatigue. He was just barely on the surface, poor guy, having been dragged out of bed after a 12-hour stint of sleeping to review his biology homework. (Most people would bounce around like caffeinated pixies after snoozing for 12 hours, but when you are a 15-year-old boy and growing at a fantastic rate, 12 hours feels like a catnap.)
“Eukaryotic cells. I keep forgetting –”
Briefly, wearily, my son explained the difference between eukaryotic cells and prokaryotic cells — “think you-karyotic” — and subsided back into his coma.
“OK, so the Krebs cycle has five phases,” I read, returning to the massive textbook on my lap. “In step one, the acetic acid subunit of acetyl CoA is combined with oxaloacetate. …”
The Christmas tree twinkled in the corner. A fire snapped in the grate. We ought to have been playing board games or reading novels, but unfortunately the Krebs Cycle required our attention whether we wanted to give it or not.
It had long been family policy for the children to do their schoolwork without much adult involvement, apart from advice and occasional proofreading. The theory was that if they struggled and conquered, they’d have the satisfaction of knowing that their achievements were their own. Yet belatedly it had become obvious that this laisse faire policy did not benefit everyone. A child who begins to flounder in math or science, disciplines where knowledge is cumulative, risks drowning later in the academic year — and needs support.
So while the decorations were still up, the boy and I were retraversing a semester’s worth of biochemistry. I was reading aloud, and he was taking notes, and in this way we hoped to solidify his hold on material that I myself hadn’t encountered since the early days of President Reagan’s first term.
Did I remember any of it? No, I did not! Did having the book on my lap, with its diagrams and photographs and bold-faced vocabulary cause the mysterious process of cell respiration to become clear to me? No, it did not.
As I read aloud to my stupefied son, I might have been uttering words from a text in Sumerian: “This causes a carbonyl group to be released as carbon dioxide and a thioester bond is formed in its place between the former alpha-ketoglutarate and coenzyme A –”
“What?”
“Do you want me to reread that bit?”
“Um, can you start at the top again? I think I drifted off.”
As I opened my mouth to remonstrate, the boy’s 17-year-old sister strolled over with an amused look on her face.
“You can’t blame him, Mummy,” she said. “He’s sitting by the fire in a soft armchair listening to you read from a biology textbook. You might as well shoot him with tranquilizer darts!”
The boy gave a wan smile. “That would be more fun, considering,” he said. At least he’d be asleep.
Meghan Cox Gurdon’s column appears on Sunday and Thursday. She can be contacted at [email protected].
