How a cell turns carbon compounds into usable energy — and why oxygen changes the whole story.
ATP — adenosine triphosphate, a nucleotide. It distributes energy within the cell.
Energy is released when ATP is hydrolysed to ADP + Pᵢ, and required to build it back.
Active transport, anabolism (building macromolecules), and movement of the cell or its parts.
Cell respiration is a controlled chemical process that releases energy from carbon compounds to make ATP.
The principal substrates are glucose and fatty acids — though many organic compounds can be used.
Gas exchange is the physical diffusion of O₂ in and CO₂ out. Respiration is the chemistry that produces the ATP.
Tap any box to learn what happens there. Trace the path that needs oxygen — and the one that doesn't.
Each step of the pathway is one box. Start with glucose and follow the arrows down.
Aerobic respiration happens here. Tap a part to see what it does.
Tap a part on the left, or a button, to see its role in aerobic respiration.
Cells that need lots of energy — muscle, liver — are packed with mitochondria.
Anaerobic respiration only partially breaks down glucose — so the ATP yield is small (~2). Aerobic completely breaks it down (~34 more).
Respiration is one piece of your metabolism. Tap a concept to light up how it connects.
Catabolism breaks things down and releases energy; anabolism builds things up and needs energy. Cell respiration is catabolic — and the ATP it makes is exactly what powers anabolism.
Tap any concept to trace its connections · tap the background to reset
Drag each term from the bank into the gap it belongs in. Two terms don't fit anywhere — that's the trap.
Single best answer, Paper 1 style. Pick one — you'll see why.