Chap. 8 (Vocab) Flashcards
Metabolism
Reactions that occur in cells that provide the body with energy
Metabolic Pathway
- Chemical reactions in cell that convert molecules into products
- Each step is catalyzed by specific enzyme
Catabolic Pathway
Breaks down large molecules into smaller subunits, releasing energy
Anabolic Pathway
Uses energy to build up larger molecules from smaller subunits (biosynthetic pathway)
Bioenergetics
Study of how energy flows through living organisms
Energy
Capacity to cause change
Chemical Energy
Potential energy available for release in a chemical reaction
Thermodynamics
Study of energy transformation
Open System
Can exchange both matter and energy with its surroundings
Isolated System
Cannot exchange matter or energy with its surroundings
Entropy
Measure of randomness or disorder in a system
Spontaneous Process
- Occurs naturally without the need for any external energy input; it happens on its own under given conditions
- Increases entropy of universe
Free Energy
Amount of energy available within a system that can be used to perform work
Exergonic Reaction
- Chemical reaction that releases free energy
- Occurs spontaneously and has a negative change in Gibbs free energy
- Product has less energy than reactants
Endergonic Reaction
- Absorbs energy from its surroundings, resulting in a positive change in free energy
- Product has more energy than reactant
Energy Coupling
Use of energy released from an exergonic reaction to drive an endergonic reaction
Phosphorylated Intermediate
A molecule that gained a phosphate group during a biochemical reaction
Activation Energy
Initial energy needed to start a chemical reaction
Transition State
Unstable condition that reactants are in due to molecules absorbing energy to break bonds
Catalysis
Acceleration of a chemical reaction by a catalyst, by lowering Ea barrier
Substrate
Reactant on which an enzyme works
Enzyme-substrate Complex
Complex when enzyme binds to its substrate molecue
Active Site
Region on enzyme where substrate binds
Induced Fit
Enzymes bind to substrates and change shape to enhance ability to catalyze reaction
Cofactor
Non-protein chemical compound required for an enzyme’s role as a catalyst
Coenzyme
Organic molecule that helps enzymes catalyze biochemical reactions
Competitive Inhibitors
Bind to active site of enzyme, competing with substrate, reducing the enzyme’s activity
Noncompetitive Inhibitors
Bind to an enzyme at a site other than the active site, reducing the enzyme’s activity
Allosteric Regulation
Molecule binds to protein at one site and affects protein function at another site
Cooperativity
How binding of a ligand at one site on a macromolecule affects the binding of a ligand at another site on the same macromolecule
Ligand
Molecule that binds to another specific molecule, called a receptor, to initiate a cellular response by delivering a signal between cell
Feedback Inhibition
Regulates the activity of enzymes in a biochemical pathway
Potential Energy
Energy stored with potential to be released- due to location/structure
Kinetic Energy
Energy in motion and being used for movement
Thermal Energy
- Energy contained within a system due to the movement of its molecules
- Measure of kinetic energy
Heat
Thermal energy in transfer between objects
Closed System
Exchange of energy is allowed but not exchange of matter
Enzyme
Protein that speeds up chemical reactions by lowering the activation energy (catalytic protein)
Catalyst
Chemical agent that increases rate of reaction w/o being consumed by reaction
Ea barrier
Total energy required to push and accelerate the reaction
Inhibitor
Substance that reduces or prevents an enzyme from working properly
