1. Bio 178 Lecture 8 Cell Structure Copyright: J. Elson-Riggins

2. Reading Chapter 5 Quiz Material Questions on P 104 Chapter 5 Quiz on Text Website (www.mhhe.com/raven7)

3. Outline Eukaryotic Cells (Cntd.)

4. The Golgi Apparatus Structure Flattened membranous sacs (cisternae). Functions Collection, packaging, sorting, and shipping of ER products. Modification (in particular glycosylation) of proteins and lipids. Orientation Cis - Receiving end. Trans - Discharging end.

5. Golgi Apparatus

6. Protein Transport from ER to Golgi

7. Golgi Apparatus http://wilfred.berkeley.edu/TEM-Gallery1/pages/Golgi.htm

8. Golgi Apparatus http://www.siena.edu/biology/faculty/cellbiology/golgi.jpg

9. Lysosomes Structure Membrane bound vesicles that contain hydrolytic emzymes. Enzymes only function at acidic pH. pH 5 in secondary lysosomes maintained by proton pumps in the membrane. Primary lysosomes not acidic. Functions Organelle breakdown & recycling. Phagocytosis.

10. Lysosome Fusing http://www.jdaross.mcmail.com/lysosome.htm

11. McGraw-Hill Video : Lysosomes

12. Organelles that Contain DNA Mitochondria Chloroplasts

13. Mitochondrion

14. Chloroplast

15. Organelles that Contain DNA Mitochondria & chloroplasts Formation of DNA Containing Organelles: The Endosymbiont Theory The Theory Mitochondria & chloroplasts were derived from prokaryotes that were engulfed by the ancestral eukaryote. Evidence 1. 2 membranes - inner folded 2.Size 3.Own circular DNA 4.Ribosomes 5.Division

16. Endosymbiosis

17. Mitochondrion

18. The Mitochondrion Size ~ 0.5-1 µm diam Membranes Outer - smooth Inner - highly folded into cristae with embedded proteins that function in oxidative metabolism. Compartments Outer - intermembrane space Inner - matrix Functions Cellular respiration.

19. The Mitochondrion (Cntd) DNA Own Circular DNA 1.Contains several genes encoding proteins for oxidative metabolism. 2.Synthesis of these proteins uses RNA and ribosomal components encoded by its own DNA. Use of Nuclear DNA 1.Nuclear DNA encodes the rest of the proteins required for oxidative metabolism. 2.Also encodes proteins required for mitochondrial division.

20. The Mitochondrion Extracted DNA DNA (arrow) & ribosomes (circle) http://cellbio.utmb.edu/cellbio/mitoch2.htm

21. Chloroplast

22. The Chloroplast Size ~ 2 µm X 5 µm Membranes Outer & inner membranes - smooth Thylakoid membrane - Forms flattened disks (thylakoids), which are stacked to form grana. Photosynthetic pigments in membrane. Compartments Stroma - bathes thylakoids Thylakoid space - inside thylakoids Functions Photosynthesis

23. The Chloroplast (Cntd) DNA Own Circular DNA Some chloroplast proteins encoded here. Use of Nuclear DNA Remaining chloroplast proteins encoded here.

24. The Cytoskeleton

25. Composition Network of protein fibers. Composed of actin (microfilaments), microtubules, & intermediate filaments. Functions Structure Transport Cell division Locomotion Anchoring of organelles

26. Distribution of The Cytoskeleton Intermediate Filaments Microtubules Actin Filaments http://www.tmd.ac.jp/artsci/biol/textbook/cellmove.htm

27. The Cytoskeleton ActinMicrotubules Intermediate Filaments http://cellix.imolbio.oeaw.ac.at/Videotour/video_tour_1.html

28. Dynamic Nature of the Cytoskeleton Actin filaments and microtubules are constantly assembling (polymerization) and disassembling (depolymerization). Plus end - Fast growing end Minus end - Slow growing end

29. Actin (Microfilaments) http://cellix.imolbio.oeaw.ac.at/Videotour/video_tour_1.html Fibroblast labeled with fluorescent phalloidin.

30. Actin (Microfilaments) http://www.microscopyu.com/articles/fluorescence/filtercubes/yfp/yf phyq/actin/yfpactinindex.html

31. Actin Filaments Size ~ 7 nm diam Composition 2 intertwined chains of the globular protein actin.

32. Functions of Actin filaments Muscle contraction Cellular extensions Cleavage furrow Anchoring Movement

33. Microtubules Functions Movement of organelles Chromosome movement