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Definition
| The collection of chemical reactions that occur in an organism. |
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| Release energy by breaking down complex molecules to simpler compounds. (degradative process) |
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| What kind of metabolic pathway is cellular respiration? |
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Definition
| Catablosim, the sugar glucose and other organic fuels are broken down to carbon dioxide and water. |
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| Consume energy to build complicated molecules from simpler ones. |
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| the study of how organisms manage their energy resources. |
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| The capacity to do work; to move matter against opposing forces, such as gravity and friction. |
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| Energy of motion; anything that moves. |
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| Stored energy; energy that matter possesses because of its location or structure. |
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| a form of potential energy; it is stored in molecules as a result of the arrangement of the atoms in those molecules. |
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| What do organisms transform? |
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Definition
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Definition
| The study of the energy transformations that occur in a collection of matter. |
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Term
| First Law of Thermodynamics |
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Definition
| (energy of the universe is constant) Energy can be transferred and transformed, but it cannot be created or destroyed. This law is also known as the PRINCIPLE OF CONSERVATION of ENERGY. |
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| Second Law of Thermodynamics |
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Definition
| Every energy transfer or transformation INCREASES the entropy of the universe. |
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Definition
| a measure of disorder; randomness |
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Definition
| a change that can occur with outside help, it can occur on its own....When a spontaneous process occurs in a system, the stability of that system INCREASES. |
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Definition
| the portion of a system's energy that can perform work when temperature is uniformed. |
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Definition
| The free energy of the system DECREASES (change in G<0); the system becomes MORE STABLE; the released free energy can be harnessed to do work. |
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Term
| What are teh two components related to Free energy (G)? |
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Definition
| G = H - TS ; H(system's total energy), S(entropy), T(temperature in Kelvin K=C + 273) |
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Term
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Definition
| Free energy can be viewed as a measure of a system's instability; its tendency to change to a more stable state. |
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Term
| Systems that tend to change sponatneously to a more stable state have: |
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Definition
| high energy, low entropy, or both. |
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Term
| Versatile criterion for spontaneous change: |
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Definition
| IN ANY SPONTANEOUS PROCESS, THE FREE ENERGY OF A SYSTEM DECREASES. |
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Definition
| a state of maximum stability; Change in G=0 |
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Term
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Definition
| net release of free energy; (-) free energy; exergonic rxns are those that occur spontaneously |
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Term
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Definition
| absorbs free energy from its surroundings..becuase it stores free energy, it is (+). these rxns are NONspontaneous |
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Term
| what happens to reactions in a closed system? |
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Definition
| it eventually reaches equilibrium adn can do no work; a cell that reaches metabolic equilibrium is dead... |
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Term
| Metabolic Disequiilibrium |
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Definition
| A cell can maintain disequilibrium because it is an open system so it has a constant flow of materials in and out of the cell. |
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Term
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Definition
| It powers cellular work by coupling exergonic reactions to endergonic reactions. |
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Term
| what are the products of ATP in hydrolysis? |
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Definition
| ADP and Pi (inorganic phosphate)..PHOSPHORYLATED, the recipient of the phospahte group. |
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Definition
| Catabolic pathways drive the regeneration of ATP from ADP and phosphate. |
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Definition
| a chemical agent that changes the rate of a reaction without being consumed by the reaction. |
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Term
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Definition
| a catalytic protein; enzymes speed up metabolic reactions by lowering energy barriers. |
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Term
| Free Energy of Activation (ACTIVATION ENERGY) |
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Definition
| the energy required to break bonds in the reactant molecules. We can think of activation energy as the amount of energy need to push the reactants over an energy barrier, or hill, so that the "downhill" part of the reaction can begin. |
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Term
| Enzymes and Activation Energy |
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Definition
| Heat speeds a reaction; but high temperature denatures proteins and kills cells. Organisms must therefore use an alternative: a CATALYST. |
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Term
| What does an enzyme do to a reaction? |
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Definition
| It speeds a reaction by lowering the EA(activation barrier) so that the precipice of the transition state is within reach even at moderate temperatures. |
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Term
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Definition
| The reactant an enzyme acts on. Enzymes are substrate specific. The enzyme binds to its substrate (or substrates, when there are 2 or more reactants). When enzyme and substrate are joined, the catalytic action of the enzyme converts the substrate to the product of the reaction. |
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Term
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Definition
| the restricted region of the enzyme molecule that actually binds to the substrate. IT is typically a pocket or groove on the surface of the protein. |
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Term
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Definition
| 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. |
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Term
| what are two environmental factors that are important in the activity of an enzyme? |
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Definition
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Term
| What are the optimal temperatures for enzymes, at which its reaction rate is fastest. |
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Definition
| In human enzymes, it is 35-40 degrees celsius (close to human body temp.) In bacteria that live in hot springs, it is about 70 degrees Celsius or higher. |
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Term
| what are the optimal pH values for enzymes? |
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Definition
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Term
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Definition
| 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; many cofactors are inorganic. |
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Term
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Definition
| when the cofactor is an organic molecule. Most vitamins are coenzymes. Cofactors funtion so that catalysis can take place. |
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Term
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Definition
| Reversible(binds by weak bonds) inhibitors that mimcs the normal substrate and competes for admission into the active site. It reduces the productivity of enzymes by blocking substrates from the active sites. This inhibition can be overcome by INCREASING the concentration of substrate. |
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Term
| Noncompetitive inhibitors |
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Definition
| Impede enzymatic reactions by binding to another part of the enzyme, which causes the enzyme molecule to change its shape/conformation, making the active site unreceptive to substrate, or leaves the enzyme to be less effective at catalyzing. |
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Term
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Definition
| a specific receptor site on some part of an enzyme molecule remote from the active site. |
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Term
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Definition
| a method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of any enzyme within that pathway. (feedback inhibition prevents the cell from wasting chemical resources to synthesize more than is necessary) |
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Term
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Definition
| An interaction of the constituent subunits of a protein whereby a conformational change in one subunit is transmitted to all others. |
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Term
| What do higher levels of organization result in? |
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Definition
| The emergence of new properties. Organization is the key to the chemistry of life. |
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