1 / 47

Transport, con't.

Transport, con't. The Na/K ATPase. Consequences of Na/K ATPase. Two ion gradients Used as energy source Electrical signaling Charge difference across membrane Membrane potential difference Negative on inside -60 to –90 mV in animal cells ~ -150 mV in bacteria -200 to –300 mV in plants

badrani
Download Presentation

Transport, con't.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Transport, con't.

  2. The Na/K ATPase

  3. Consequences of Na/K ATPase • Two ion gradients • Used as energy source • Electrical signaling • Charge difference across membrane • Membrane potential difference • Negative on inside • -60 to –90 mV in animal cells • ~ -150 mV in bacteria • -200 to –300 mV in plants • Not just due to these ions • Phosphatidylserine on inside of PM • Other ions

  4. Indirect (secondary) AT • Na/glucose symporter • Intestinal absorptive cells

  5. Thermodynamics of Transport

  6. Thermodynamics of Transport, charged

  7. Intracellular compartments The Endomembrane System

  8. Endoplasmic Reticulum • Smooth ER • Rough ER • ER cisternae • ER lumen

  9. Smooth ER • Lipid biosynthesis • Membrane phospholipids • Cholesterol • TAG • Drug detoxification • Glycogen metabolism (catabolism) • Calcium storage

  10. Rough ER • "rough" with ribosomes • Synthesis of • Membrane proteins for endomembrane system • Secreted proteins • Initial glycosylation of many of these

  11. Golgi body Camillo Golgi, 1898

  12. Golgi • Glycosylation of secretory and membrane proteins • Sorting/trafficking

  13. Secretory and membrane proteins • Synthesis starts in cytoplasm on ribosomes • Signal sequence determines where it goes • Nucleus • Mitochondria • Post-translational import • RER (endomembrane system) • Co-translational import

  14. Pg. 679

  15. Co-translational import—secreted protein SRP=signal recognition particle

  16. Membrane bound proteins

  17. Post-translational import (mitochondrial) TOM= translocase of outer membrane TIM=translocase of inner membrane

  18. Post-translational modification • Proteolytic cleavage • Glycosylation • Phosphorylation • Addition of a lipid group (lipid anchored proteins) • Adenylation • Etc.

  19. Glycosylation

  20. The Big Picture

  21. Bulk Transport • Exocytosis • Endocytosis • pinocytosis • Phagocytosis • Autophagy • Receptor-mediated endocytosis

  22. Exocytosis-constitutive secretion-regulated secretion

  23. Endocytosis-pinocytosis

  24. Receptor Mediated Endocytosis • Bulk transport • Specific

  25. The Big Picture

  26. Coated Vesicles • Clathrin • Golgi to endosomes • Endocytosis • COP I • COP II • ER and Golgi • Within the Golgi

  27. How do coated vesicles go to the right place and fuse with the right membrane? The “SNARE” hypothesis

  28. SNARE • Vesicle-SNAP-receptors (v-SNAREs) • Target-SNAP-receptors (t-SNAREs) • SNAP=soluble NSF attachment proteins • NSF=N-ethylmaleimide-sensitive factor

  29. Lysosomes • Digestive enzymes • Low pH (4-5) • Develop from late endosomes/hydrolases from Golgi • Activated by lowering the pH

More Related