Don’t call them bad names, call them these names… Key terms to start… Don’t call them bad names, call them these names…

Definition time! Metabolism – the sum of all chemical reactions in a cell or organism Energy – the capacity to do work, the potential for change in a physical system Two states of energy: Kinetic – the energy of motion Potential – the stored energy an object possesses due to its position relative to other objects

More… Work – the transfer of energy, used to move an object against an opposing force Reaction types Anabolic reaction (endergonic) – when energy is required to build complex molecules from simple ones VERSUS Catabolic reaction (exergonic) – when energy is released by breaking up complex molecules into simpler ones

Adenosine Triphosphate ATP! Adenosine Triphosphate

ATP Structure ATP has the same overall structure of RNA, but has three (tri) phosphate groups [Recall: nucleic acids all have a nitrogenous base, a 5-C ringed sugar, and phosphate group(s)]

A Powerhouse… Is considered universal energy “currency” for the body Provides energy for movement of cells and within cells, for movement of substances across cell membranes against the concentration gradient, and all mediated endergonic reactions (see Table 1, p141) Allows for mechanical, transport, and chemical work

ATP + H2O  ADP + Pi ΔG = -30.5kJ/mol Why so energetic? The three negatively charged phosphate groups contain large amounts of energy Their electrons “mutually repel” each other and so these bonds are quite weak These bonds are easily broken by water through catalyzed hydrolysis ATP + H2O  ADP + Pi ΔG = -30.5kJ/mol

The Reaction

How does this really work? Energy Coupling – the transfer of energy from one reaction to another to drive the second reaction