Every carbon out of glucose, and every electron it was holding — tracked from the cytosol to the matrix, before oxygen has appeared even once.
Respiration looks like a wall of names. It is much simpler read as bookkeeping: six carbons go in, six carbon dioxides come out, and the energy goes somewhere you need to be able to point to.
Burning glucose in one go would release its energy as heat. Dozens of small steps let a cell capture much of it instead.
They collect electrons and hydrogen at each oxidation step and deliver them to the chain. Reduced carriers are the real product here.
All six carbons are gone by the end of Krebs, but only four ATP have been made. The payoff is in the next lesson.
Tap each part. Location matters more than usual here — it explains what can run without oxygen and what cannot.
Tap the outer membrane, intermembrane space, cristae, matrix, the cytosol panel, or the DNA.
Five steps from glucose to the end of Krebs, counting every carbon and every carrier as you go. The last panel is the one to memorise.
Everything in this lesson uses the first mechanism, and it accounts for a small minority of the total yield. The second mechanism is the whole of the next lesson.
An enzyme hands a phosphate from a substrate straight to ADP. Four per glucose, and no oxygen needed.
Electrons from NADH power a proton pump; the gradient then drives ATP synthase. Around twenty-six ATP.
Without a final electron acceptor the carriers stay reduced, the chain backs up, and only the four direct ATP remain available.
Tap a node to light up its connections. The pink dashed link is the point of the whole lesson.
Read down the left column: glucose, pyruvate, acetyl CoA, Krebs.
Drag a term into a gap, or tap a term and then tap a gap. Two terms belong nowhere.
Glycolysis takes place in the and splits glucose into two molecules of , generating ATP by phosphorylation. Pyruvate then enters the mitochondrial , where it loses a carbon as carbon dioxide — a — to form . This joins a four-carbon molecule called to begin the Krebs cycle, whose main product is the reduced carrier .
Single best answer. You get the reasoning as soon as you commit.
Biology by Bradford