Lipase catalyzes the hydrolysis of fats. One molecules of triacylglycerol is hydrolyzed by hormone sensitive (HSL) lipase to generate 2-monoacylglycerol that is subsequently hydrolyzed by monoglyceride lipase to yield glycerol and fatty acids. In times of energy need, such as fasting and exercise, adipocyte lipolysis is markedly increased by catecholamines that activate Gs-coupled receptors. These receptors, in turn, activate adenylyl cyclase to generate cyclic cAMP. Rising cellular concentrations of cAMP activate protein kinase A (PKA;this PKA is cAMP dependent) that phosphorylates HSL at three serine residues (563, 659 and 660) in a 150 amino acid stretch termed the regulatory module. This regulatory module is found within the C-terminal domain of HSL, which also contains the catalytic triad. Phosphorylation results in increased hydrolytic activity , translocation of HSL from the cytosol to the lipid-droplet surface and enhanced TAG breakdown in the cell.
Describe the pathway involved in the degradation of one triacylglycerol molecule in an adipocyte cell.
Describe the steps involved in converting glycerol into triacylglycerol. Explain the roles of the citrate shuttle with regards to the fat synthesis pathway by describing how acetyl groups are transported into the cytosol and the paths the products of the cytosolic cleavage reaction take. As in glycolysis and the degradation of glucose, the degradation of fatty acids also requires an initial investment of ATP energy. State the reaction or reactions where ATP energy is needed before fatty acids can be...
Research and describe a cell receptor involved in cell signaling that utilizes one of the following mechanisms. 1. RTK pathway (Receptor Tyrosine Kinase Cascade) 2. GPCR (G Protein Coupled Receptor) 3. Ion Channel Receptors 4. Ligand Gated Your summary of the protein receptor must include the following: 1. Name of the receptor and its ligand. 2. A brief description of the pathway (what is activated and how). 3. Name of the pathway it is responsible for activating and what the...
Describe two ways that degradation of incomplete mRNAs is good for the health of the cell (hint; why is the mRNA incomplete?).
describe the metabolic pathways, and energetics, involved or generated, during the catabolism of one molecule of glucose by aerobic respiration
Q) Indicate if the following molecule will activate or inactivate the given enzyme or pathway (A) A high amount of citrate for fatty acid synthesis: (B) Glucagon for acetyl-CoA carboxylase (C) Insulin for triacylglycerol lipase
Propose a Glyoxylate to CAC evolutionary pathway and describe what enzymes are involved and what enzyme mutations may have given rise to this pathway.
5) Describe the blood vessels involved in coronary circulation 6) Explain the pathway (or blood vessels) involved in pulmonary and systemic circuit.
Describe the signal transduction pathway (steps and where each occurs in the cell)
5.DISEASE AND PATHWAYS: Most drugs target proteins involved in signaling pathways in the cell. Describe two examples by which a protein can be chemically altered and thereby act as a logic switch in a signaling pathway in the cell. 6.MOLECULAR DRUG DOCKING: Why is molecular docking (e.g. autodock vina) take less time to run than molecular dynamics? What aspect of molecular reality regarding the target protein is sacrificed during simulation to obtain computational speed?
Describe why the alternate complement pathway is activated only when associating with microbial cell surfaces.