CAMPBELL BIOLOGY CHAPTER 8 EXAM QUESTIONS AND ANSWERS

CAMPBELL BIOLOGY CHAPTER 8 EXAM QUESTIONS AND ANSWERS metabolism - answer- the totality of an organism's chemical reactions metabolic pathway - answer- a series of chemical reactions that begins with a specific molecule, which is then altered in a series of steps catalyzed by specific enzymes, resulting in a certain product catabolic pathway (breakdown pathway) - answer- metabolic pathway that releases energy by breaking down complex molecules into smaller, simpler compounds ex/ cellular respiration (organic fuels break down to CO₂ and water) anabolic pathway (biosynthetic pathways) - answer- metabolic pathway that consumes energy to build complex molecules from simpler ones ex/ protein from amino acids bioenergetics - answer- the study of how energy flows through living organisms energy - answer- the capacity to cause change; exists in various forms, some perform work; the ability to rearrange a collection of matter kinetic energy - answer- energy associated with motion heat (thermal energy) - answer- kinetic energy associated with the random movement of atoms or molecules potential energy - answer- energy that matter possesses because of its location or structure chemical energy - answer- the potential energy available for release in a chemical reaction due to the molecule's structure thermodynamics - answer- the study of energy transformations (system [matter under study, can be isolated/open] vs. surroundings) first law (of thermodynamics) - answer- The principle of conservation of energy: Energy can be transferred and transformed, but it cannot be created or destroyed. enthropy - answer- a measure of disorder, or randomness; (appears as increasing amounts of heat and less ordered forms of matter) second law (of thermodynamics) - answer- Every energy transfer or transformation increases the entropy (disorder) of the universe. ex/ bear making kinetic energy - produces heat and CO₂ (as it exhales) spontaneous process - answer- a process that can occur without an input of energy; it is "energetically favorable", it increases entropy of the universe; a process that is moving toward equilibrium ex/ water flowing downhill (Gibbs) free energy - answer- the portion of a system's energy that can perform work when temperature and pressure are uniform throughout the system, as in a living cell; measure of a system's instability (tendency to change to stability) (change in) free energy (∆G) - answer- ∆G = ∆H - T∆S ∆G = [final energy] - [initial energy] equilibrium - answer- maximum stability; ∆G = 0; a cell that is metabolically at this is dead exergonic reaction - answer- a spontaneous chem reaction with a net release of free energy (also some released as heat); ∆G 0; the greater the decrease, the greater the amount of work that can be done; reactants have higher free energy, products have less free energy endergonic reaction - answer- a nonspontaneous chem reaction that absorbs free energy from its surroundings; ∆G 0, the quantity of energy needed to drive the reaction ("get the reaction to go"); reactants have less free energy, products have more free energy chemical, transport, mechanical - answer- the three main kinds of work that a cell does/uses ATP for energy coupling (Rx coupling) - answer- the use of an exergonic process to drive an endergonic one; makes the overall process spontaneous; made possible with ATP hydrolysis · A+B → C+D ∆G = +5 (endergonic) · X+Y → Z+W ∆G = -7 (exergonic) · A+B+X+Y → C+D+Z+W ∆G = -2 (exergonic) ATP (adenosine triphosphate) - answer- ribose with nitrogenous base adenine and a chain of three phosphate groups; bonds broken through hydrolysis; cycles 7.3 kcal/mol - answer- energy given off in this exergonic reaction (therefore it would be -): ATP + H₂O → ADP + P + energy; energy need to drive this endergonic reaction: ADP + P + energy → ATP enzyme - answer- a macromolecule (protein) that acts as a catalyst (most ending in -ase); 1. lowers activation energy 2. not used up 3. specific for reaction catalyst - answer- a chemical agent that speeds up a reaction without being consumed by the reaction