3.1 ATP: The Cell's Energy Currency

Notes

Cells power their work with ATP (adenosine triphosphate).

• ATP has the base adenine, the sugar ribose, and three phosphate groups.
• Breaking off the last phosphate releases energy and leaves ADP (adenosine diphosphate).
• Cells recharge ADP back into ATP using energy from food (cellular respiration).
• ATP powers active transport, muscle contraction, building molecules, and more.
• Autotrophs (producers) make their own food; heterotrophs (consumers) get food by eating other organisms.