01:119:115 Lecture Notes - Lecture 7: Activation Energy, Endergonic Reaction, Ribose
Document Summary
Metabolism: sum of all chemical reactions of organism- maintains homeostasis. Metabolic pathway begins with specific molecule and ends with product. 2 types of metabolic pathways: catabolic pathway: breaking down complex molecules to simpler ones. Heat (thermal energy): random movement of atoms or molecules. First law of thermodynamics: energy cannot be created or destroyed only converted from one form to another. Second law of thermodynamics: every energy transfer or transformation increases entropy. Light energy enters ecosystem and heat energy exits. Total energy in universe is constant but total energy available to do work decreases over time. Gibbs free energy=h + ts=energy available to do work kj/mole. Delta g < 0 = energy released, disorder from order. Delta g > 0 = energy add to cause reaction; nonspontaneous. Adenosine triphosphate: ribose (5 carbon sugar), adenine (nitrogenous base), 3 phosphate groups. Atp drives endergonic reaction by phosphorylation (transfers phosphate group to reactant) Enzymes speed up reactions by lowering energy barriers.