LIFE 102 Lecture Notes - Lecture 8: Activation Energy, Sucrase, Chemical Energy
Document Summary
Atp (adenosine triphosphate) does work in the cell by energy coupling, the use of an exergonic process to drive an endergonic one. The bonds between the phosphate groups of atp"s tail can be broken by hydrolysis. Energy is released from atp when the terminal phosphate bond is broken. Atp is a renewable resource that is regenerated by addition of a phosphate group to adp. The energy to phosphorylate adp comes from catabolic reactions in the cell. The chemical potential energy temporarily stored in atp drives most cellular work. Energy for cellular work: endergonic, energy consuming process. A catalyst is a chemical agent that speeds up a reaction without being consumed by the reaction. Hydrolysis of sucrose by the enzyme sucrase is an example of an enzyme- catalyzed reaction. Every chemical reaction between molecules involves bond breaking and bond forming. The initial energy needed to start a chemical reaction is e(sub)a. Enzymes catalyze reactions by lowering activation energy barrier.
