Cell and Molecular Part 2

• Acetyl CoA: Made using pyruvate from glycolysis, a two-carbon molecule with an attached coenzyme A. Oxidized in the citric acid cycle. Has a high energy thioester bond.
• Active site:  The part of an enzyme where a substrate binds and catalysis takes place which results from the three-dimensional folding of the enzyme. It is usually a groove or pocket which accommodates the substrate(s) with high affinity.
• Adaptor proteins: Do not have enzymatic activity, mediate protein-protein interactions.
• Adenylyl cyclase: catalyzes conversion of ATP to cAMP; creates cAMP and activates its signalling.
• Aerobic respiration:  Exergonic process using oxygen as the ultimate electron acceptor, with a significant portion of the released energy conserved as ATP.
• Affinity: The degree to which a substance tends to combine with another
• Allosteric regulation: regulation by binding of an activator or inhibitor at a site that is not the active site.
• Anaerobic respiration: Molecules other than oxygen (i.e. sulfur, nitrates) are the terminal electron acceptors
• Autocrine signals: Signals sent from one cell to itself (self signalling)
• Binding site: On a receptor where the ligand binds to produce cellular signals. Amino acid residues in the binding site interact with the ligand. Binding alters the receptor and can induce a conformational change of the receptor or cause the receptors to cluster together.
• Ca2+-calmodulin complex: regulates activity of many enzymes allowing it to control a wide range of cellular processes such as gluconeogenesis, cell death, inflammation and memory.
• Calmodulin: a protein that is present in all eukaryotic cells that allows Ca ions to transduce signals. Ca ions cause a conformational change in the protein
• cAMP: Cyclic AMP, commonly used as a second messenger.
• Catalysis: The process of using a catalyst to facilitate a reaction in which the bonds between the atoms in the molecules are broken rearranged and rebuilt into new molecules. Includes bond distortion, proton transfer and electron transfer.
• Cellular respiration: a series of chemical reactions that break down glucose to produce ATP; oxidation-driven flow of electrons from reduced coenzymes to an external electron acceptor, usually accompanied by the generation of ATP
• Coenzymes: An organic prosthetic group, often a vitamin derivative
• Covalent modification:  regulation by the addition or removal of covalent chemical modifications

   
• CRE: Cyclic AMP response elements, 7 nucleotide DNA sequences.
• CREB: Cyclic AMP Response Element Binding protein, binds CRE sequences
• Diabetes: results from the inability to make insulin (type I) or the inability to respond to insulin (type II)
• Electron transport chain: Electrons are transferred from NADH and FADH2 to oxygen via a series of energetically favourable steps by a series of complexes made up of multiple proteins and coenzymes. Electron transport between each carrier is spontaneous and exergonic;. Complexes are located in the inner mitochondrial membrane.
• Endocrine signalling: Long-distance signalling, often mediated by hormones (within the body signalling)
• Enzymes: chemical catalysts used to drive reactions and processes essential to life (usually ATP). They are made of proteins and help overcome the activation energy barrier to allow reactions to proceed faster and easier.
• Epinephrine: A hormone produced during stress. Leads to glycogen breakdown. Signals to many cell types. Causes glucose to enter the bloodstream, ensures we have the energy to fight or flee, even if you haven’t eaten recently.
• External electron acceptor: An electron acceptor that is not a by-product of glucose metabolism.
• Feedback inhibition: when the final product of an enzyme pathway negatively regulates an earlier step in the pathway.
• Fermentation: The metabolism of pyruvate produced from glycolysis that recycles NADH, making NAD+ available for continued glycolysis.
• Fibronectins: adhesive ECM glycoproteins. Two subunits linked near the C-termini by disulfide bonds
• F0F1 complexes: protrude into the matrix, H+ channels that are composed of multiple polypeptides, together make up ATP synthase molecules. The diffusion of H+ across ATP synthases drives ATP synthesis.
•  GI: A class of GPCR that inhibits adenylyl cyclase, signalling decreases cAMP synthesis
• GQ:  a class of GCPR that signal via IP3 and DAG (diacylglycerol) to activate phospholipase C, not adenylyl cyclase.
• Gs: A class of GPCR that stimulates adenylyl cyclase, signalling promotes cAMP synthesis
• Glucagon: A hormone secreted by the pancreas that helps regulate normal glucose levels. Increases blood glucose through glycogen breakdown.
• Gluconeogenesis: The formation of new glucose from other carbon containing molecules such as pyruvate, lactate and glutamine. It is the reverse of glycolysis and therefore shares many intermediates and enzymes with glycolysis. This process requires energy and allows our liver cells to make and release glucose while we are fasting.
• GLUT4: insulin regulated glucose transporter responsible for insulin regulated glucose uptake into fat and muscle cells. Without insulin, GLUT4 is not sent to the surface of muscle or fat cells so glucose uptake is inefficient. Glucose accumulates in the blood and some cells do not have access to the glucose needed for energy production and storage as glycogen.
• Glutamine: A molecule that provides carbon and nitrogen for biosynthesis, just as important as glucose for metabolism.
• Glycolysis: the first step in using glucose to generate energy, does not require energy. Requires an energy input and produces a net gain of 2 ATP molecules per glucose, and also produces 2 NADH molecules. It is needed in both aerobic and anaerobic organisms. A ten-step reaction sequence that oxidizes one glucose molecule into two 3-carbon pyruvate molecules.
• GPCRs: G-protein coupled receptors, named because ligand binding activates a G-protein
• G-protein: Guanine nucleotide binding protein, heterotrimeric protein complex with 3 subunits (alpha, beta and gamma). Bind to either GDP or GTP, which determines the activity of the G-protein.
• Hormones: Signalling molecules released from specialized endocrine cells, travel long distances via the bloodstream.