Term
| the 3 stages of generating energy from the oxidation of food |
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Definition
1: digestion (large molecules being broken down into smaller molecules)
2: numerous small molecules being degraded into a few simple units that play a central role in metabolism; most of these simple units are converted into acetyl CoA
3: producing ATP from the complete oxidation of acetyl CoA; this involves the citric acid cycle and oxidative phosphorylation |
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Term
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Definition
| large molecules being broken down into smaller molecules |
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Term
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Definition
-tricarboxylic acid (TCA) cycle
-Krebs cycle |
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Term
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Definition
| the extraction of energy from fuels |
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Term
| depiction of the stages of catabolism |
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Definition
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Term
| 3 things living organisms need energy for |
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Definition
1: mechanical work in muscle contraction and cellular movements
2: active transport of molecules and ions
3: synthesis of macromolecules and other biomolecules from simple precursors |
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Term
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Definition
| photosynthetic organisms that obtain energy by trapping sunlight in a chemical form |
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Term
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Definition
| organisms that obtain energy thru the oxidation of C fuels |
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Term
| some basic principles that underlie energy flow in all living systems |
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Definition
1: fuels are degraded and large molecules are constructed step by step in a series of linked rxns called metabolic pathways
2: an energy currency common to all life forms, ATP, links energy releasing pathways with energy requiring pathways
3: the oxidation of C fuels powers the formation of ATP
4: although there are many metabolic pathways, a limited number of types of reactions and particular intermediates are common to many pathways
5: metabolic pathways are highly regulated to allow the efficient use of fuels and to coordinate biosynthetic processes |
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Term
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Definition
| series of linked rxns in which fuels are degraded and large molecules are constructed |
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Term
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Definition
links energy releasing pathways with energy requiring pathways
this is the energy currency |
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Term
| what powers the formation of ATP? |
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Definition
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Term
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Definition
| a linked series of chemical rxns that begins with a particular biomolecule and converts it into some other required biomolecule in a carefully defined fasion |
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Term
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Definition
| defined metabolic pathways in the cell |
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Term
| 2 broad classes of metabolic pathways |
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Definition
1: those that convert energy from fuel into biologically useful forms (catabolic)
2: those that require input of energy to proceed (anabolic) |
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Term
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Definition
| breaking down fuels to release cellular energy |
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Term
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Definition
| using energy to synthesize biomolecules |
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Term
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Definition
| can be either anabolic or catabolic, depending on conditions in the cell |
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Term
| an important principle of metabolism |
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Definition
| although biosynthetic and degradative pathways often have rxns in common, the regulated, irreversible reactions of each pathway are almost always distinct from each other |
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Term
| how anabolic and catabolic rxns interact |
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Definition
| energy released from catabolic rxns is used to power anabolic rxns |
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Term
| 2 criteria a metabolic pathway has to meet |
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Definition
1: the individual rxns must be specific
2: the entire set of rxns that constitute the pathway must be thermodynamically favored |
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Term
| the nature of a rxn depends on... |
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Definition
-the nature of the reactants and products
-the concentrations of reactants and products |
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Term
| a thermodynamically unfavorable rxn can be driven by... |
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Definition
| a thermodynamically favorable rxn |
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Term
| ATP can be thought of as... |
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Definition
| the currency that facilitates the commerce of the cell (metabolism) |
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Term
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Definition
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Term
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Definition
| adenine with a triphosphate unit attached |
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Term
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Definition
| because its triphosphate unit contains 2 phosphoanhydride linkages |
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Term
| phosphoanhydride linkages |
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Definition
| formed between 2 phosphoryl groups accompanied by the loss of a water molecule |
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Term
| how energy is released from ATP |
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
| phosphates that can be released from ATP hydrolysis |
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Definition
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Term
| when ATP is formed from ADP and Pi in chemotrophs |
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Definition
| when fuel molecules are oxidized |
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Term
| when ATP is formed from ADP and Pi in phototrophs |
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Definition
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Term
| how an otherwise unfavorable rxn can be made possible |
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Definition
| by coupling it to ATP hydrolysis |
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Term
| standard free energy of hydrolysis |
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Definition
| the energy released when the phosphorylated compound transfers the phosphoryl group to water under standard conditions |
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Term
| magnitude of ΔG⁰' vs. phosphoryl-transfer potential |
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Definition
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Term
| factors that differentiate the stability of the reactants and products |
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Definition
1: electrostatic repulsion
2: resonance stabilization
3: increase in entropy
4: stabilization due to hydration |
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Term
| how electrostatic repulsion affects stability of reactants and products |
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Definition
| ATP has 4 negative charges in close proximity to each other; the repulsion between them is reduced when ATP is hydrolyzed |
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Term
| how resonance stabilization affects stability of reactants and products |
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Definition
| phosphate has greater resonance stabilization when released from ATP |
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Term
| how increase in entropy affects stability of reactants and products |
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Definition
| products of ATP hydrolysis have 2 molecules instead of 1 |
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Term
| how stabilization due to hydration affects stability of reactants and products |
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Definition
| water binds to ADP and Pi, making the synthesis of ATP less favorable |
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Term
| why ATP is an efficient carrier of phosphoryl groups |
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Definition
| because its phosphoryl-transfer potential is intermediate among the biologically important phosphorylated molecules |
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Term
| characteristics of phosphate and its esters that render it useful for biochemical systems |
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Definition
1: they are thermodynamically unstable, but kinetically stable, thus their energy can be manipulated by enzymes
2: the stability of phosphate esters is due to the negative charges that make them resistant to hydrolysis in the absence of enzymes
3: their kinetic stability makes them ideal regulatory molecules, added to proteins by kinases and removed only by phosphatases |
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Term
| one of the primary roles of catabolism |
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Definition
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Term
| is ATP an immediate or ling term donor of free energy? |
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Definition
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Term
| the fundamental mode of energy exchange in biological systems |
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Definition
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Term
| depiction of the ATP-ADP cycle |
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Definition
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Term
| some things that require ATP |
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Definition
-motion
-active transport
-biosynthesis
-signal amplification |
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Term
| some things that turn ADP into ATP |
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Definition
-oxidation of fuel molecules
-photosynthesis |
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Term
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Definition
| rxns where one atom loses electrons (oxidation) and another gains electrons (reduction) |
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Term
| reduction of a C atom vs. free energy released by its oxidation |
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Definition
proportional
the more reduced it tis to begin with, the higher the free energy released by its oxidation |
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Term
| why fats are more efficient fuels than carbohydrates |
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Definition
| because the C's in fats are more reduced |
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Term
| what happens to the energy of oxidation in ATP synthesis? |
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Definition
| it is initially trapped as a high-phosphoryl-transfer-potential compound and then used to form ATP |
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Term
| what C oxidation energy is used for in the formation of ATP |
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Definition
-creating a compound with high phosphoryl-transfer potential
-creating an ion gradient |
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