Breakdown pathways, release energy. Breaking bonds include: hydrolysis, digestion (ex: digesting polymers), catabolic reactions
Require input of energy; building up things: dehydration synthesis, synthesis (ex: building polymers), anabolic reactions.
The portion of a systems; energy that can perform work when temperature and pressure are uniform throughout the system. (Delta G) When energy is released (exergonic), G is negative.
Combing Exergonic Reactions with Endergonic so the energy released in the exergonic is used to power the endergonic reaction.
Adenosine Triphosphate (ATP)
Made of the sugar ribose with the nitrogen base adenine and a chain of three phosphate groups bonded to it. If this has the same structure with only 2 phosphate groups it is ADP (DIphosphate). Requires energy to add another phosphate group. Bonds between phosphates can be broken through hydrolysis (adding an H2O), when this happens energy is release (exergonic reaction)
The adding of a phosphate group to another molecule, recipient of phosphate group is said to be phosphorylated.
Chemical agent that speeds up a reaction without being consumed by the reaction.
Biological catalysts. Usually proteins, they facilitate chemical reactions, are required for most biological reactions, highly specific. These are named for the reaction they catalyze- ends in "ase," ending follows what they catalyze.
Amount of energy required for starting a reaction. Enzymes reduce this requirement to start a reaction.
How Enzymes Work
Substrates bind to active site (site of enzyme that is specific to those enzymes). The enzyme works through: Synthesis- bring substrates (reactant an enzyme acts on) close together and in correct position. Digestion- active site binds substrate and puts stress on bonds that must be broken, making it easier to separate molecules.
Factors Affecting Enzyme Function
Enzyme Concentration, Substrate Concentration, temperature, pH, Salinity, Activators, Inhibitors
Activators: 1) Cofactors- non protein, small inorganic compounds & ions. 2) Coenzymes- non proteins, organic molecules, bind temporarily or permanently to enzyme near active site (ex: vitamins)
Inhibitor & Subsrate "compete" for active site. Reduce enzyme productivity by blocking substrates from active site. (ex: penicillin)
These do not directly compete with the substrate, they bind to another area of enzyme changing the shape of the enzyme and therefore the active site becomes less effective. (ex: anti-cancer drugs)
Inhibitor permanently binds to enzyme.
~Competitor: permanently binds to active site.
~Allosteric: permanently binds to allosteric site, permanently changes shape of enzyme.
Any case in which a protein's function at one site is affected by the binding of a regulatory molecule to a separate site. Can result in inhibition or stimulation
Stabilizes the shape that has functional active sites.
Stabilizes the shape that has a functional inactive site.
Regulation & coordination of production. A metabolic pathway is switched off by the inhibitory binding of its end product to an enzyme that acts early in the pathway. (ex: synthesis of amino acid, isoleucine from amino acid, threonine. Isoleucine becomes the allosteric inhibitor of the first step in the pathway.