Recommended
More Related Content
What's hot
Similar to Nucleus
Similar to Nucleus (20)
More from uploadlessons
More from uploadlessons (20)
Recently uploaded
Recently uploaded (20)
Nucleus
- 1. Fig. 1.11
- 2. Nucleus: structure and function Nucleolus Nucleoplasm nuclear envelope Heterochromatin = too compacted, transcriptionally inactive Euchromatin = can be transcriptionally active
- 3. Nuclear envelope and lamina Nuclear pore N. lamina cytoplasm heterochromatin
- 5. Lamins are filamentous proteins in the intermediate filament family Lamin phosphorylation in prophase disassembles the nuclear lamina & allows for nuc. envel. breakdown Laminins are extracellular proteins, unrelated
- 6. Nuclear pore • nuclear localization signals (nuclear import signals) • nuclear export signals • highly regulated
- 8. Inner Membrane and matrix electron transport system ADP3- ATP4- pyruvate Krebs cycle NADH ATP synthaseFADH2 hi [H+ ] Antiporter P04 -2 H+ symporter
- 9. Endosymbiotic theory: Mitochondria are similar to prokaryotes • Own circular, naked DNA • Own ribosomes - similar to prokaryotic – e.g. sensitive to same inhibitors • Divide by fission • Double membrane suggests endocytosis
- 10. Lysosomes: membranous organelles filled with digestive enzymes • Breakdown endocytosed materials – Thru’ phagocytosis or receptor mediated endocytosis • Breakdown old organelles (residual body) • Acidic pH
- 12. Membrane trafficking •RER to cis Golgi •Modified in Golgi (glycosylation, phosphorylation) •Sorted at trans Golgi network into •Lysosomal •Regulated •constitutive
- 13. Synthesis of secreted and membrane proteins Ribosomes Rough endoplasmic reticulum
- 15. Signal hypothesis: signal peptide, SRP, SRP-receptor, translocon SRP = signal recognition particle
- 16. Smooth ER, lipid synthesis, detox, Ca2+ sequestration
- 17. Golgi
- 18. Transport thru’ Golgi cisternae is vectorial Cis Medial Trans
- 19. mannose removal N-acetylglucosamine addition MEDIAL RER retrieval, PO4 on mannose, mannose removal CIS & CGN fucose and glucose addition TRANS sialic acid addition, sorting TGN Protein modifications occur in steps in the Golgi. The extent of changes varies.
- 21. trans Golgi network regulated secretion lysosomal pathway constitutive secretion Sorting at the TGN
- 23. Plasma membrane & Fluid mosaic model
- 24. Phospholipids are most common in membranes Polar Head Fatty acid tails
- 26. Thermodynamics drives membranes to form sealed compartments H2O Cut open liposome
- 27. Fluidity means that lipids (& proteins) can “float” in the membrane via diffusion Time
- 28. Three classes of membrane proteins: Transmembrane proteins (a type of IMP) OUT IN Extracellular domain (ECD) Intracellular domain (ICD) Transmembrane domain Oligosaccharides - always face out
- 29. Three classes of membrane proteins: Lipid- anchored membrane proteins (IMPs) OUT IN Covalently linked to a glycophospholipid. E.G.: Normal cellular scrapie protein & alkaline phosphatase Covalently linked to fatty acid E.G.: ras
- 30. Three classes of membrane proteins: Peripheral membrane proteins (PMPs) OUT IN Or, PMPs could bind to specific lipid heads. Specific interaction between IMP & PMP
- 31. IMPs as α-helix or β-barrel
- 34. Four mechanisms by which solute molecules move ACROSS membranes Simple diffusion across bilayer Simple diffusion thru channel Facilitated Diffusion thru’ passive transporters Active transport
- 35. Membrane Potential Affects Molecular Movement A. neutral No effect on inward transport No effect on outward transport B. cation Favors inward transport Opposes outward transport C. anion Opposes inward transport Favors outward transport
- 36. Passive transport by channel proteins: don’t bind solute & can be ligand-, voltage-, or stress-gated
- 37. Passive Transport by Facilitated diffusion •Solute binds transporter protein •So, transport is saturable
- 39. Active transport by the Na/K pump or ATPase