Order costs something. Every structure a cell maintains is paid for continuously, in a currency it holds only seconds of.
Cells do not run on glucose. They run on ATP — and they hold barely any of it, regenerating the entire pool many times a minute.
Dense, stable and transportable. Excellent for keeping energy; useless for spending it directly.
Small, soluble and immediately spendable. A typical cell turns over its own mass in ATP every day.
You hold only a few seconds' worth at any moment. Stop making it and the shortage is immediate.
Tap each part. The instability is the feature, not a flaw — and it comes from charge, not from the bond itself.
Tap the base, the sugar, any of the three phosphates, the terminal bond, or the charge panel.
Five steps that turn an impossible reaction into a spontaneous one, without breaking any thermodynamics.
One sign decides everything. But it decides direction only — never speed, and never whether the reaction will happen this century.
Products hold less free energy than reactants. Energy is released and the reaction can proceed unaided.
Products hold more. Energy must be supplied from outside, and no enzyme can substitute for it.
Glucose oxidising in air is spontaneous, yet sugar keeps for years. Direction and rate are separate questions.
Tap a node to light up its connections. The pink dashed link is the rule that makes ATP necessary at all.
Follow the left column downward: sunlight to glucose to ATP to work.
Drag a term into a gap, or tap a term and then tap a gap. Two terms belong nowhere.
The immediate energy currency of the cell is . A reaction with a negative change in is described as and is , whereas a reaction with a positive value is and will not proceed alone. Cells solve this by energy , in which the of ATP pays for the uphill reaction. Transferring the terminal phosphate group onto another molecule is called .
Single best answer. You get the reasoning as soon as you commit.
Biology by Bradford