Intro to Metabolism

• kinases


  Enzymes that catalyze the transfer of a phosphate group from a high-energy molecule (such as ATP) to a substrate molecule, typically a protein, lipid, or nucleotide. This phosphorylation often regulates the activity of the substrate.
• phosphorylases


  Enzymes that catalyze the addition of a phosphate group to a molecule, typically using inorganic phosphate as the phosphoryl group donor.
• synthases


  Enzymes that catalyze the synthesis of complex molecules from simpler ones, often without the requirement of ATP or other high-energy molecules.
• Synthetases


  Similar to synthases, but these enzymes typically require ATP or another high-energy molecule to drive the synthesis reaction.
• Ligases


  Enzymes that catalyze the joining of two molecules, often coupled with the hydrolysis of ATP or another high-energy molecule.
• Lyases


  Enzymes that catalyze the cleavage of bonds within a molecule, resulting in the formation of a new double bond or the addition of atoms to a double bond without hydrolysis or oxidation.
• Oxidases 


  Enzymes that catalyze the transfer of electrons from a substrate molecule to oxygen, often coupled with the reduction of oxygen to hydrogen peroxide or water.
• Oxygenase


  Enzymes that catalyze reactions where molecular oxygen (O2) is incorporated into a substrate molecule, usually in the form of a hydroxylation reaction.
• Dioxygenases


  Enzymes that catalyze the incorporation of both atoms of molecular oxygen into a substrate molecule, often resulting in the formation of a double bond or the introduction of functional groups.
• Monooxygenases


  Enzymes that catalyze the insertion of a single oxygen atom from molecular oxygen into a substrate molecule, typically requiring a cofactor such as NAD(P)H or flavin.
• Dehydrogenases


  Enzymes that catalyze the removal of hydrogen atoms from a substrate molecule, typically transferring them to an electron carrier such as NAD+ or FAD.
• 1. Metabolites


  Small molecules that are intermediates or products of metabolism, encompassing a wide range of compounds such as sugars, amino acids, lipids, and nucleotides.
• Intermediary metabolism


  The set of biochemical reactions involved in the synthesis, degradation, and interconversion of metabolites within cells. It includes pathways such as glycolysis, the citric acid cycle, and the pentose phosphate pathway.
• negative deltaG


  indicates that a reaction is spontaneous and releases energy
• postive deltaG


  indicates that a reaction is non-spontaneous and requires energy input
• negative deltaH


  indicates that a reaction releases heat energy (exothermic)
• positive deltaH


  indicates that a reaction absorbs heat energy (endothermic)
• negative deltaS


  indicates a decrease in randomness or disorder in a system
• positive deltaS


  indicates an increase in randomness or disorder in a system
• homolytic cleavage

  A type of bond cleavage where the electrons in the bond are divided equally between the resulting fragments, leading to the formation of radicals.
• Heterolytic cleavage


  A type of bond cleavage where one fragment retains both electrons from the bond, resulting in the formation of ions (cation and anion)
• Nucleophiles


  Molecules or ions that donate a pair of electrons to form a new covalent bond, typically attracted to positively charged or electron-deficient atoms
• Electrophiles


  Molecules or ions that accept a pair of electrons to form a new covalent bond, typically attracted to negatively charged or electron-rich atoms.
• Carbanion


  An organic molecule or ion with a negatively charged carbon atom, possessing a lone pair of electrons.
• Carbocation


  An organic molecule or ion with a positively charged carbon atom, lacking one electron and therefore having only six valence electrons.
• Aldol condensation


  A type of organic reaction in which an enol or enolate ion reacts with a carbonyl compound to form a β-hydroxy ketone or aldehyde.
• Claisen condensation


  A type of organic reaction involving the formation of a β-ketoester or β-diketone from the condensation of an ester or ketone with an ester or another ketone, respectively.
• Electromotive force (emf)


  In the context of biochemistry, it often refers to the potential difference generated by the flow of electrons through a biological system, such as in redox reactions within cells or across biological membranes. It's measured in volts (V).
• ADP (Adenosine Diphosphate)


  A nucleotide composed of adenine, ribose, and two phosphate groups. It is formed by the hydrolysis of ATP (Adenosine Triphosphate) and serves as an important intermediate in cellular energy metabolism.
• AMP (Adenosine Monophosphate)


  A nucleotide composed of adenine, ribose, and one phosphate group. It serves as a precursor to ADP and ATP and also plays regulatory roles in various biochemical processes.
• Adenylation


  The process of adding an adenylyl group (adenosine monophosphate, AMP) to a molecule. This modification is often involved in signaling pathways or the activation of substrates for further biochemical reactions.
• Adenylate kinase


  An enzyme that catalyzes the reversible transfer of a phosphate group between ATP and AMP, producing two ADP molecules. This enzyme plays a crucial role in cellular energy homeostasis by maintaining the balance between ATP and ADP/AMP levels.
• Creatine kinase


  An enzyme that catalyzes the reversible transfer of a phosphate group between ATP and creatine, producing ADP and phosphocreatine (PCr). This reaction serves as a temporal energy buffer in tissues with high and fluctuating energy demands, such as skeletal muscle and brain.
• Dehydrogenation


  The removal of hydrogen atoms from a substrate molecule, typically accompanied by the transfer of electrons to an electron carrier (such as NAD+ or FAD), resulting in the oxidation of the substrate.
• Reducing equivalent


  A molecule or compound that can donate electrons to another molecule, thereby reducing it. Common reducing equivalents in biological systems include NADH, NADPH, and FADH2.
• Standard reduction potential


  The measure of the tendency of a chemical species to acquire electrons and undergo reduction under standard conditions (defined as 25°C, 1 atm pressure, and 1 M concentration). It is commonly used to compare the relative strengths of oxidizing and reducing agents in redox reactions.
• Oxidoreductase


  A broad class of enzymes that catalyze redox reactions involving the transfer of electrons from a donor molecule (the reducing agent) to an acceptor molecule (the oxidizing agent). These enzymes play crucial roles in various metabolic pathways, including energy production, biosynthesis, and detoxification.
• The six mechanisms that influence metabolic regulation and control are: gene expression regulation, post-translational modifications, allosteric regulation, feedback inhibition, compartmentalization, and hormonal regulation.
• hormonal regulation


  Control of metabolism at the systemic level by hormones that act on target tissues to modulate enzyme activity, gene expression, and substrate availability, coordinating metabolic responses to environmental and physiological changes.
• compartmentalization


  Spatial organization of metabolic pathways within organelles or cellular compartments, allowing simultaneous operation of different pathways and regulation of metabolic flux through membrane transporters and protein translocators.