BIOL 2050 1st Edition Lecture 12Outline of Last Lecture I. Active TransportII. Exocytosis and EndocytosisOutline of Current Lecture III. MetabolismIV. Energya. Orderb. Energy and MetabolismV. Enzymesa. RegulationCurrent Lecture-Cells are miniature chemical factories- Cells extract energy and apply energy to perform workMetabolism: totality of an organism’s chemical reactionsI. Interactions between chemicals II. Metabolic Pathwaysa. Catabolic pathway: releases energy by breaking down complex molecules into simpler compoundsi. Cellular respirationb. Anabolic Pathways: consumes energy to build complex moleculesi. Bioenergetics: study of energy managementii. Amino acids to proteinsEnergyI. Kinetic Energy: motionII. Heat (Thermal Energy): kinetic energy associated with random movement of atoms or moleculesIII. Potential Energy: energy that matter possesses IV. Chemical Energy: chemical reactions- Energy can be converted from one form to anotherV. Thermodynamics: study of energy transformationsa. First Law: the energy of the universe is constantThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.b. Second Law: every energy transfer or transformation increases the entropy (disorder) of the universeVI. Spontaneous Processes: occur without energy and can happen quickly or slowlyOrderCells are ordered structuresEvolution doesn’t violate laws of thermodynamicsI. Free Energy: energy that can do work when temperature and pressure are uniforma. ∆ G = ∆ H – T ∆ Si. G: change in free energyii. H: change in total energyiii. S: change in entropyiv. T: temperaturev. Only processes with negative G are spontaneous b. Measures a system’s instabilityc. Once equilibrium is reached work can no longer be performedd. More free energy= less stable and greater work capacitye. Spontaneous Change: can perform work only when its moving toward equilibriumFree Energy and MetabolismII. Exergonic Reaction: releases energy and is spontaneousIII. Endergonic Reaction: takes in energy and not spontaneousIV. Equilibrium: a. Cells are not at equilibriumi. Open systemsii. Catabolic pathways in cellsV. ATPa. Coupling exergonic to power endergonicb. Cell’s energy shuttlec. Composed of a ribose, three phosphate groups, and an adenine basei. Broken by hydrolysis and releases energyii. Phosphate group given ofiii. Phosphorylated intermediate: recipient of phosphate groupd. Regeneration i. ATP is renewable4ii. Add energy from catabolic processesEnzymesI. Catalyst: chemical agent that speeds up a chemical reactiona. Enzymes are the catalysts in biologyb. Lower Energy Activation barrieri. The initial energy needed to get a chemical reaction goingII. Substrate: reactant that an enzyme acts ona. Enzyme-substrate complex: a complex formed when an enzyme and substrate bindIII. Active Site: the region on the enzyme where the substrate bindsa. Induced fit: brings chemical groups of the active site into positions that enhance their ability to catalyze the reactionIV. An enzyme’s activity can be afected by a. Temperature and pH changesb. ChemicalsV. Cofactors: nonprotein enzyme helpersa. Ex. VitaminsVI. Inhibitorsa. Competitive Inhibitors: bind to the active site of an enzyme, competing with the substrateb. Noncompetitive Inhibitors: bind to another part of the enzyme and cause it to change shape so the active site is less efective.Regulation- Chemical chaos would result is a cell’s metabolic pathways were not tightly regulated- Cells switch genes that code for certain enzymes on or of Allosteric Regulation: may either inhibit or stimulate an enzyme’s activityCooperativity: amplifies enzyme activityFeedback Inhibition: shuts down pathway when enough product