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Unformatted text preview: Chapter Eight: An I nt roduction to Metabolism Definitions 1) Bioluminescence: is a process by which the energy stored in certain organic molecules is converted to light. 2) Bioenergetics: is the study of how energy flows through living organisms. Notes- ATP is short for adenosine t riphosphate.- ATP contains the sugar ribose, with the nitrogenous base adenine and a chain of three phosphate groups bonded to it.- The breaking down of ATP into ADP and HOPO 3 2- is exergonic and releases 7.3 kcal of energy per mole of ATP. The recipient of the HOPO 3 2- (phosphate group) is said to be phosphorylated.- All three phosphate groups in an ATP molecule are negatively charged. These like charges are crowded together, and their mutual repulsion contributes to the instability of this region of the ATP molecule.- Metabolism: I t is the totality of an organisms chemical reactions. A metabolic pathway begins with a specific molecule, which is then altered in a series of defined steps, resulting in a certain product. Types of metabolic pathways: o Catabolic pathways: These are the degradative processes or breakdown pathways. They are exergonic reactions: They proceed with a net release of free energy. The products of the process are more stable than the reactants. The products are less organized than the reactants. They are said to be (down-hill) reactions. o Anabolic pathways: These are the processes that consume energy to build complicated molecules from simpler ones. They are also called biosynthetic pathways. They are endergonic reactions: They absorb free energy from their surroundings. The products of the process are less stable than the reactants. The products are more organized than the reactants. They are said to be (up-hill) reactions. If a chemical process is exergonic, then the reverse process must be endergonic. Energy coupling: is the use of an exergonic process to drive an endergonic one....
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- Spring '11
- Organic Molecules