Module7LectureNotes.pdf LIFE 210
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This 4 page Class Notes was uploaded by Mikaela Maldonado on Wednesday October 7, 2015. The Class Notes belongs to LIFE 210 at Colorado State University taught by Paul J Laybourn in Fall 2015. Since its upload, it has received 48 views. For similar materials see Introductory Eukaryotic Cell Biology in Entomology at Colorado State University.
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Date Created: 10/07/15
Lecture 17 339 Active transport gt Movement against concentration or charge gradient I Energy is being stored I Primary Active Transport Uses energy source directly Sodium Potassium pump and ATP O NAKATPase mechanism gt gt gt gt E1 is start is a form of the enzyme as a transporter I Faces into the cytoplasm I High affinity for sodium 3 binding sites and low affinity for potassium E2 form I Faces out of the cell I Low affinity for sodium and high for potassium 2 binding sites E1 binds a sodium which triggers a phosphorylation of ATP and movement of the pump I Causes a negative free energy change Potassium is required for the recycling of the process I Allows for dephosphorylating makes it more stable than E1 and gives a negative free energy change Moves against the concentration gradient There is a recitation question that builds off of this concept Process occurs in the same protein I Active transport thermodynamics Coupled reactions NAingtNAout deltaG is coupled with ATPgtADPP deltaG O each piece is called an elementary step or half reaction O enzyme will transfer the phosphate group to find this intermediate phase I Secondary Active Transport Uses energy source indirectly Energy stored in an electrochemical gradient Cotransport O Uniportone binding site O Symporttwo binding sites in same direction O Antiport two binding sites in the opposite direction Still has a delta G because of the coupled reaction for the transport NAglucose transporter O Intestinal lumen VVVV Glucose and NA have a high concentration inside Pump glucose against gradient against the concentration gradient Uses sodium electrochemical gradient to fuel this Glucose has a low affinity so is paired with NA gt Still has a deltaG gt Video under Module 7 Lecture Materials Etc has a good explanation of this system NAglucose antiporter O Switch the binding so affinity for glucose is released when facing the outside of the cell at the binding of Na molecules Clicker QUESTION A change you could make to the NAglucose transporter sufficient to make it pump glucose out of the cell rather than in include a Increasing the NA concentration inside the cell b Making it a NAglucose antiporter c Inverting the orientation of the transporter proteins in the membrane d Replace NA binding with K binding 339 Glucose transport Intestinal Lumen to Blood gt Intestinal epithelial cells I Basis for Gatorade gt Antiport NAK ATPase pump I Low concentration NA inside the cells gt Symport naglucose I Driven by nak pump that then brings glucose into the cell gt Uniport I Drives glucose out of the cell through passive transport Lecture 18 339 Protein Trafficking gt Nuclearcytoplasmic importexport in cancer cells I Functionality is determined through the balance established by the nuclear pore complex I Metabolic enzymes for example are degraded by letting themselves in the nucleus I Tumor suppressors and oncoproteins activities are dependent on nuclear or cytoplasmic localization I Exportin CRM 1 regulates nuclear export importins are proteins that bring things in the nucleus is a potential target for anticancer drugs I BRCAZ mutation affecting the binding of a protein DSSl DSSl normally functions to block CRMl binding and nuclear export Results in BRCA2 and Rad51 cytoplasmic localization and impaired dsDNA break repair increased breast and ovarian cancer Think about the importance of such mutations gt Endoplasmic Reticulum and Golgi I Proteins are synthesized right into the membrane of the ER and then sent off with the Golgi to wherever they are needed Disulfide bonds Use past knowledge from last unit stabilization are created generally on the ERcan interfere with the proper function This quality control is integrally linked with survival of cells and properly folded proteins Secretory pathway and unfolded protein response or ER stress ER stress is something in the environment reducing agents that stress the cell Functions in both initiating and protecting cells from apoptosis Apoptosiswhen cells think they are going cancerous they dieproblem in the development of cancer Golgi may have a role in regulating initiation of apoptosis Vesicular Traffickingmovement of things in cells Endocytosis Protein plasma membrane localization and function of O Cell signaling receptors gt Tells the cell to divide for example gt Receptor to tell to stop dividing O Cellcell adhesion complexes Normal function is dependent on dynamic localization O Signaling depends on shutting off signals too O Adhesion complexes are continuously being results in a dynamic steady state O Become unbalance in a cancer cell Signaling receptors Growth or cell division signals bind the receptors like receptor tyrosine kinases These signals are normally attenuated turned off by a receptor in endocytosis Endocytosis can lead to recycling or degradation of the receptors Signal receptors are recycled rather than degraded Reduced endocytosis and signal shut off results in too many receptors within cancerceHs O Aides in dividing and replicating that make a cancer cell Adhesion Complexes Normal epithelial cellspolar tightjunctions Polarized cells Dynamic but maintained with adherin junctions circles Cadherins are another connection that form lines Basolateral surface on the bottom Apical surface on the top is ridged in order to increase surface area of the cells to make more efficient Cancer cellsloss of cell polarity tight junctions O Imbalance between new synthesis recycling degradation O Tight junctions lost O Adherin junctions break down Integrins 00000 Cell migration or crawling Act as cell feet aww D Focal contact contain integrins Metastasis O Escape normal local O Invade O Increased recycling to front O Decrease degradation gt ALL BECAUSE OF INTEGRINS ALLOWING MOVEMENT I Cyclical rotation of new integrins so that the cells can move and avoid being killed so can infect other things muahaha I Exocytosis Cellcell signaling through vesicles Small RNA transfer O Regulation of gene expression in neighbor cells O Support cancer cells recruited gt Kinda like being slugged by your neighbor and being told to do something from the new RNA that penetrated your membrane gt Affects on Protein Trafficking I Changes are markers for malignant and metastic cells I May provide targets for anticancer drugs I May provide new means for drug delivery and new type of drugs small RNAs Transfervesiclesliposomes Clicker Question In cancer cells protein trafficking A Is one of the few cellular processes remaining unchanged B Provides no targets for developing new anticancer drugs C Dynamics of membrane protein localization are often out of balance D Is not participated in metastasis E The only changes are in nuclear localization