Chapter 8 Introduction to metabolism Flashcards
Bioenergetics
(1) The overall flow and trans- formation of energy in an organism. (2) The study of how energy flows through organisms
kinetic energy
The energy associated with the relative motion of objects. moving matter can perform work by imparting motion to other matter
Thermal energy
Kinetic energy due to the random motion of atoms and molecules; energy in its most random form
Heat
Thermal energy in transfer from one body of matter to another
Potential energy
The energy that matter possesses as a result of its location or spatial arrangement (structure)
Chemical energy
Energy available in molecules for release in a chemical reaction; a form of potential energy
Metabolism
The totality of an organism’s chemical reactions, consisting of catabolic and anabolic pathways, which manage the material and energy resources of the organism
Metabolism
The totality of an organism’s chemical reactions, consisting of catabolic and anabolic pathways, which manage the material and energy resources of the organism
Metabolic pathway
A series of chemical reactions that either builds a complex molecule (anabolic pathway) or breaks down a complex molecule to simpler molecules (catabolic pathway).
Catabolic pathway
A metabolic pathway that releases energy by breaking down complex molecules to simpler molecules
Anabolic pathway
A metabolic pathway that consumes energy to synthesize a complex molecule from simpler molecules
Thermodynamics
The study of energy transformations that occur in a collection of matter
First law of Thermodynamics
The principle of conservation of energy: Energy can be transferred and transformed, but it cannot be created or destroyed
Second law of Thermodynamics
The principle stating that every energy transfer or transformation increases the entropy of the universe. Usable forms of energy are at least partly converted to heat
Entropy
A measure of molecular disorder, or randomness
Spontaneous process
A process that occurs without an overall input of energy; a process that is energetically favorable
Free energy
The portion of a biological system’s energy that can perform work when temperature and pressure are uniform throughout the system. The change in free energy of a system (∆G) is calculated by the equation ∆G = ∆H - T∆S, where ∆H is the change in enthalpy (in biological systems, equivalent to total energy), ∆T is the absolute temperature, and ∆S is the change in entropy
Exergonic reaction
A spontaneous chemical reaction in which there is a net release of free energy
Endergonic reaction
A non-spontaneous chemical reaction in which free energy is absorbed from the surroundings
ATP (adenosine tri-phospahte)
n adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells
Phosphorylated intermediate
A molecule (often a reactant) with a phosphate group covalently bound to it, making it more reactive (less stable) than the unphosphorylated molecule.
Enzyme
A macromolecule serving as a catalyst, a chemical agent that increases the rate of a reaction without being consumed by the reaction. Most enzymes are proteins
Catalysis
A process by which a chemical agent called a catalyst selectively increases the rate of a reaction without being consumed by the reaction
Energy coupling
In cellular metabolism, the use of energy released from an exergonic reaction to drive an endergonic reaction
