BSC 114: Chapter 8
26 Cards in this Set
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Metabolism
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All the chemical changes that occur in an organism.
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Metabolic pathway
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Begins with a specific molecule, which is then altered in a series of defined steps, resulting in a certain product. Each step of the pathway is catalyzed by a specific enzyme.
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Enzymes
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Serve as catalysts ( chemical agents that change the rate of a reaction without being consumed by the reaction)
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Catabolic pathway
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Breaks down complex molecules to simpler compounds ( from proteins to amino acids) down hill reaction
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Anabolic pathway
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Consume energy to build complex or complicated molecules from simpler ones ( synthesis of proteins from amino acids) sometimes called biosynthesis pathways. Uphill reaction
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Energy coupling
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Interaction between catabolic and anabolic pathways
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Energy
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The capacity to do work. The ability to rearrange a collection of matter ( eg. Your cells expend ______ moving substances across membranes )
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Kinetic energy
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When energy is associated with the relative motion of objects. A pool player uses the motion of the cue stick to push the cue ball, which in turn moves the other balls.
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Potential energy
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An object not presently moving may still posses energy. Energy possessed because of its location or structure. Water behind a dam.
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Chemical energy
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The potential energy available for release in a chemical reaction. (Ex. Molecules store energy because of the arrangement of their atoms) refers to potential energy available for release In a chemical reaction.
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Dehydration reactions
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Catabolic pathways release energy by breaking down complex molecules
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Thermodynamics
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The study of energy transformations that occur in a collection of matter is called _____?
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1st law of thermodynamics
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Energy can be transferred and transformed but it can not be created or destroyed. AKA conservation of energy. (Eg. An electric company does not make energy but it converts it to a form we can use. ) ( putting gas in your car)
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2nd law of thermodynamics
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Every energy transfer or transformation increases the entropy of the universe. ( entropy is a measure of disorder) entropy is less apparent in biological systems because a great deal of energy is lost through heat. (Driving your car using the gas)
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Heat
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____Is energy in a random state, we have not created or destroyed energy. Biological systems are not very effective because a great deal of energy is lost through _____?
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Free energy (G)
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The portion of a systems energy that can perform work when temperature and pressure are uniform throughout the system, as in a living cell. (G) one way to determine whether metabolic reactions are spontaneous is by measuring _____?
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The change in free energy (delta G)
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Delta G= delta H - T delta S
Delta H symbolizes the change in the systems enthalpy ( total energy)
Delta S symbolizes the change in the systems entropy.
T is the absolute temperature in kelvin (K) units.
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Delta G
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When we know this we can predict whether the reaction is spontaneous (without outside energy) spontaneous doesn't necessarily mean fast, simply that it can occur eventually without energy.
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Spontaneous reactions
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Have a negative delta G value (delta G < 0)
( process that have a positive or zero Delta G are never _________)
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Equilibrium
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Max stability
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Reversible
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Most chemical reactions are _______( and proceed forward and backward at the same rate)
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Exergonic reaction
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Negative delta G. Reactions proceed with a net release of free energy ("energy outward") because the chemical mixture loses free energy. ( G decrease) spontaneous
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Endergonic reaction
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Positive delta G. Reactions absorb free energy from the environment (energy Inward) stores free energy. Non spontaneous
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ATP ( adenosine triphosphate)
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___contains the sugar ribose, with the nitrogenous base adenine and the energy of ____ is stored in the bonds between three phosphate groups. The source of energy that drives cellular work is _____
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Triphosphate
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The ____ tail is highly unstable
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Phosphorylated
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A molecule that receives the phosphate is____
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BSC 114: STUDY GUIDE