| Term | Definition |
|---|
| Potential energy | energy of position |
| Kinetic energy | energy of motion |
| Metabolism | all of the chemical reactions that occur within an organism |
| Anabolic reaction | synthesis; the combining of atoms or molecules to form new and larger molecules |
| Catabolic reaction | breakdown of more complex substances into simpler ones with release of energy |
| 1st Law of Thermodynamics | the law that states that energy cannot be created nor destroyed |
| 2nd Law of Thermodynamics | spontaneous reactions proceed with an increase in disorder (entropy) |
| Total energy | usable energy + unusable energy |
| Enthalpy (H) | total energy |
| Free Energy (G) | usable energy that can do work ex. requirement for all the chemical reactions of cell growth, cell division, maintenance of cell health |
| Entropy (S) | usable energy, measures the amount of disorder in the system x the absolute temperature (T) |
| Exergonic Reactions | (catabolic reactions) breakdown an ordered reactant, releasing free energy ex. complex molecules- free energy + small molecules |
| Endergonic reaction | (anabolic reaction) requires or consumes free energy ex. free energy + small molecules - large molecules |
| chemical equilibrium | balance between forward and reverse reactions (static state), no net change |
| Adenosine Triphosphate | An organic compound containing adenine, ribose, and three phosphate groups; captures and transfers the free energy, needed to do chemical work |
| Synthetic work | building of macromolecules |
| Concentration work | concentration of chemical gradients |
| Electrical work | created by the movement of electrical ions across a gradient |
| Rate | the speed at which it move towards equilibrium |
| Catalyst | substances that speed up reactions without being permanently altered |
| Enzymes | molecules usually proteins or nucleic acids that act as catalysts in biochemical reactions |
| Activation energy | the energy needed to change the reactants into unstabe molecular forms |
| enzyme-catalyzed reactions | reactants substrate molecules bind to a particular site on the enzyme |
| enzyme orient substrates | part of activation energy needed to start a reaction, used to bring together specific atoms between which bonds are to form ex. citrate |
| Enzyme strain in substrate | an enzyme can cause bonds in the substrate to stretch, putting it in an unstable transition state ex. lysozyme |
| Enzymes temporarily add chemical groups to substrates | side chains of amino acids may be a participant in making substrates chemically active ex. chymotrypsin |
| Acid-Base catalysis | acidic or basic side chains of teh amino acid forming the active site may transfer H+ ions to or from the bond substrate, destabilizing the covalent bond in the substrate permitting it to break |
| covalent catalysis | functional group in a side chain forms a temporary covalent bond with part of the substrate |
| metal ion catalysis | metal ions, firmly bound to side chains of the enzyme, can gain or lose electrons without detaching from the enzyme, makes them important participants in oxidation-reduction reactions, involve loss or gain of electrons |
| Induced Fit | 3-D shapes of enzymes shape caused by substrate binding |
| Prosthetic groups | distinctive, non-amino acids atoms or molecular groupings that permanently bound to their enzymes |
| Co-Factors | inorganic ions that bind to certain enzymes ex. Copper, Zinc |
| Co enzyme | carbon-containing molecule, required the action of enzymes, small compared to the enzyme to temporarily bind (organic, vitamins) |
| competitive inhibitor | compete with the natural substrate for the active site (reversible) |
| Non-competitive inhibitor | bind to the enzyme at a site distinct from the active site, causes a change in the shape of the enzyme that alters the active site, bind substrate molecules (reversible) |
| Allostery | change in enzyme shape due to non-competitive inhibitor binding , refers to any change in a proteins tertiary or quaternary induced by non-covalent binding of a ligand |
| Inactive form | a shape that cannot bind the substrate but can bind an inhibitor |
| active form | can be stabilized by binding of an activator to a third site on the enztme |
| Catalytic subunit | active site is present on one , subunit of a protein's quaternary structure which has the active site |
| Regulatory subunits | regulatory sites for activators and/or inhibitors are on different polypeptide sequences |
| Commitment Step | 1st step in a pathway, once the enzyme-catalyzed reaction occurs, "ball is rolling" and the other reactions happen in sequence leading to the end-product |
| Feedback inhibition/end-product inhibition | a present at a high concentration, some of it binds to an allosteric site on the commitment step enzyme, causing it to become inactive |
| Isozymes | that catalyzes the same reaction but has different chemical composition and physical properties |
Combine with other sets
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