Ch. 8 Key Concepts: - An organism's metabolism transforms matter and energy, subject to the laws of thermodynamics. - The free-energy change of a reaction tells us whether or not the reaction occurs spontaneously. - ATP powers cellular work by coupling exergonic reactions to endergonic reactions. - Enzymes speed up metabolic reactions by lowering energy barriers. - Regulation of enzyme activity helps control metabolism.
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| 2778262379 | cooperativity | A type of substrate binding to a multi-active site enzyme, in which the bindng of one substrate molecule facilitates the binding of subsequent substrate molecules. A graph of reaction rate vs. substrate concentration appears sigmoidal. Note that cooperativity can be found in other situations as well, for example, hemoglobin binds oxygen cooperatively. | 0 | |
| 2846187690 | catabolic pathways | Metabolic pathways that release energy by breaking down complex molecules into simpler compounds. | 1 | |
| 2846187691 | anabolic pathways | Metabolic pathways that consume energy to build complicated molecules from simpler ones. | 2 | |
| 2846187692 | bioenergetics | Flow of energy through an animal. Limits its behavior, growth, reproduction. | 3 | |
| 2846187693 | energy | Ability to do work | 4 | |
| 2846187694 | kinetic energy | Energy associated with motion. | 5 | |
| 2846187695 | thermal energy | Heat energy, the total kinetic and potential energy of all the particles in a substance. | 6 | |
| 2846187696 | potential energy | Stored energy that results from the position or shape of an object | 7 | |
| 2846187697 | chemical energy | Energy available in molecules for release in a chemical reaction; a form of potential energy. | 8 | |
| 2846187698 | thermodynamics | the study of conversions between thermal energy and other forms of energy | 9 | |
| 2846187699 | isolated system | A system that exchanges neither matter nor energy with its surroundings. | 10 | |
| 2846187700 | open system | A system in which both energy and matter are exchanged with the surroundings. | 11 | |
| 2846187701 | 1st law of thermodynamics | Energy cannot be created or destroyed | 12 | |
| 2846187702 | entropy | A measure of disorder, or randomness | 13 | |
| 2846187703 | 2nd law of thermodynamics | the state of entropy of the entire universe, as a closed isolated system, will always increase over time, the changes in the entropy in the universe can never be negative | 14 | |
| 2846187704 | free energy | Measures 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. | 15 | |
| 2846187705 | spontaneous change | Differences or change in a system that proceeds without a net input of energy from an outside source | 16 | |
| 2846187706 | exergonic reaction | Reaction that proceeds with a net release of free energy. | 17 | |
| 2846187707 | endergonic reaction | Reaction that absorbs free energy from its surroundings. | 18 | |
| 2846187708 | chemical work | The making and breaking of chemical bonds. Enables cells and organisms to grow, maintain a suitable internal environment, and store information needed for reproduction and other activities. | 19 | |
| 2846187709 | transport work | The pumping of substances across membranes against the direction of spontaneous movement | 20 | |
| 2846187710 | mechanical work | generate kinetic movement ex: cillia, flagella, muscle contraction | 21 | |
| 2846187711 | energy coupling | use the energy released from an exergonic reaction to provide the energy needed to drive an endergonic reaction forward | 22 | |
| 2846187712 | phosphorylated | a molecule that receives a phosphate group from ATP | 23 | |
| 2846187713 | enzyme | A type of protein that speeds up a chemical reaction in a living thing | 24 | |
| 2846187714 | catalyst | A substance that initiates or accelerates a chemical reaction without itself being affected | 25 | |
| 2846187715 | activation energy | the minimum amount of energy required to start a chemical reaction | 26 | |
| 2846187716 | induced fit | The change in shape of the active site of an enzyme so that it binds more snugly to the substrate, induced by entry of the substrate. | 27 | |
| 2846187717 | optimal conditions | the environmental conditions under which the enzyme works the best- ideal temperature, pH of an enzyme. Temperature is usually around 30-40 degrees celsius. pH is around 6-8, but has exceptions. | 28 | |
| 2846187718 | cofactors | Any nonprotein molecule or ion that is required for the proper functioning of an enzyme. Cofactors can be permanently bound to the active site or may bind loosely with the substrate during catalysis | 29 | |
| 2846187719 | coenzymes | An organic molecule that is a necessary participant in some enzymatic reactions; helps catalysis by donating or accepting electrons or functional groups; e.g., a vitamin, ATP, NAD+. | 30 | |
| 2846187720 | competitive inhibitors | An enzyme inhibitor that competes with substrate for binding at the active site of the enzyme. When the inhibitor is bound, no product can be made. | 31 | |
| 2846187721 | noncompetitive inhibitors | A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing its conformation so that it no longer binds to the substrate. | 32 | |
| 2846187722 | allosteric regulation | The modification of active-site activity through interactions of molecules with other specific sites on the enzyme | 33 | |
| 2846187724 | feedback inhibition | process in which a stimulus produces a response that opposes the original stimulus; also called negative feedback | 34 |
