Ch. 6 Warm-Up

1. Ch. 6 Warm-Up • At minimum, what structures or components must a cell contain to be alive? • What are the differences between plant and animal cells? • In biology, “Structure dictates function”. Think of a type of cell in your body. In what way is its structure related to its function? Explain.

2. Warm-Up • Contrast prokaryotic vs. eukaryotic cells. • List and describe the contents inside of the nucleus of a eukaryotic cell. • Describe the structure of the nuclear envelope.

3. Warm-Up • Compare the diffusion times with the SA:V ratio of the agar blocks. Explain how the diffusion time and SA:V ratio are related. • Calculate your group’s Mass/Time for your competition cube. Compare with the other groups. How effective was your group’s cell design?

4. Warm-Up • List 3 differences between plant and animal cells. • An antibody (a protein molecule) is produced and released by a plasma cell. List the pathway that this protein takes in the cell from it’s production until it is released to the outside of the cell. (Hint: The antibody travels through the endomembrane system.) • What would happen to a cell if it did not have fully functional lysosomes?

5. Chapter 4 A Tour of the Cell

6. You Must Know • Three differences between prokaryotic and eukaryotic cells. • The structure and function of organelles common to plant and animal cells. • The structure and function of organelles found only in plant cells or only in animal cells. • How different cell types show differences in subcellular components. • How internal membranes and organelles contribute to cell functions. • How cell size and shape affect the overall rate of nutrient intake and waste elimination.

7. History of the Cell Theory • Before microscopes, people thought diseases were caused by curses and the supernatural.

8. How were cells discovered?

9. Robert Hooke • Used an “early” Light Microscope to observe dead “cells” in bark of a Cork Oak tree He coined the term “cells” because he described what he saw as “many little boxes” that reminded him of the cubicles, or cells, where monks live.

10. Antonie Van Leeuwenhoek- • Made microscopes – able to grind lenses to increase magnification to 10x Hooke’s microscope • First to observe living cells • Spyrogyra genus – type of algae • Termed them Animalcules (protists)

11. 3 types of microscopes • Light microscope – uses light to view a specimen • Scanningelectronmicroscope –uses electrons to scan the surface of cells to determine 3D structure • Transmissionelectronmicroscope – uses electrons that pass through specimen to study structures within.

12. S.E.M Images DNA Tardigrade “water bear” Pollen

13. T.E.M. Images

14. 2 Types of Cells: • Prokaryotes: Domain Bacteria & Archaea • Eukaryotes (Domain Eukarya): Protists, Fungi, Plants, Animals

16. A Prokaryotic Cell (bacteria)

17. Eukaryotic Animal Cell

18. Prokaryote Vs.Eukaryote • “before”“nucleus” • No nucleus • DNA “free floating” in nucleoid space • Cytosol • Ribosomes • NO Membrane-bound organelles • SMALL • Primitive • i.e. Bacteria & Archaea • “true”“nucleus” • Has nucleus and nuclear envelope • Cytosol • Membrane-bound organelles with specialized structure/function • Much larger in size • Create multicellular organisms • More complex • i.e. plant/animal cell

19. Cell Size and Scale http://learn.genetics.utah.edu/content/begin/cells/scale/ Scale of the Universe: http://www.onemorelevel.com/game/scale_of_the_universe_2012

21. Why don’t cells grow bigger? • Why are there multicellular organisms with trillions of cells? • Why aren’t we just hundreds of really large cells?

22. Cells must be small to maintain a large surface area to volume ratio • Large S.A. allows  rates of chemical exchange between cell and environment

23. Surface area to volume ratio: • Surface area = membrane space • This is where all the transport occurs • nutrients into the cell occur • Wastes out of the cell • Volume = internal organelles within the cell • The more volume = the greater demand for more nutrients and the higher amount of wastes produced

24. Think About it… • Why will cells stay small to maintain a large surface area compared to a small internal volume?

25. Calculate Volume of a Sphere:

26. Surface Area Example (Animal): Small Intestine: highly folded surface to increase absorption of nutrients • Villi: finger-like projections on SI wall • Microvilli: projections on each cell

27. Folds  Villi  Microvilli

28. Shape determines function

29. Surface Area Example (Plant): Root hairs: extensions of root epidermal cells; increase surface area for absorbing water and minerals

30. Cell Organelles

31. Nucleus • Function: control center of cell • Contains DNA (& mRNA) • Surrounded by double membrane (nuclear envelope) • Continuous with the rough ER • Nuclear pores: control what enters/leaves nucleus • Chromatin: complex of DNA + proteins; makes up chromosomes • Nucleolus: region where ribosomes (rRNA + proteins) are formed

33. Why would the nucleus have so much protection?

34. Ribosomes • Function: protein synthesis • Composed of rRNA + protein • Large subunit + small subunit • Types: • Free ribosomes: float in cytosol, produce proteins used within cell • Bound ribosomes: attached to ER, make proteins for export from cell

35. Endomembrane System: Regulates protein traffic & performs metabolic functions

36. Bell Work • Pick up Water Potential Notes Page • Get out Organelles pogil • Get out power point of organelles

37. Endoplasmic Reticulum (ER) • Network of membranes and sacs • Types: • Rough ER: has ribosomes on its surface • Function: package proteins for secretion, send transport vesicles to Golgi, make replacement membrane • Smooth ER: no ribosomes on surface • Function: synthesize lipids, metabolize carbs, detox drugs & poisons, store Ca2+

38. Endoplasmic Reticulum (ER)

39. Golgi Apparatus • Function: synthesis & packaging of materials (small molecules) for transport (in vesicles); produce lysosomes • Series of flattened membrane sacs (cisternae) • Cis face: receives vesicles • Trans face: ships vesicles

40. Lysosomes • Function: intracellular digestion; recycle cell’s materials; programmed cell death (apoptosis) • Containshydrolytic enzymes

41. Vacuoles • Function: storage of materials (food, water, minerals, pigments, poisons) • Membrane-bound vesicles • Eg. food vacuoles, contractile vacuoles • Plants: large central vacuole -- stores water, ions

45. Parts of plant & animal cell p 108-109

47. Mitochondria • Function: site of cellular respiration • Double membrane: outer and inner membrane • Cristae: folds of inner membrane; contains enzymes for ATP production; increased surface area to  ATP made • Matrix: fluid-filled inner compartment

48. Chloroplasts • Function: site of photosynthesis • Double membrane • Thylakoid disks in stacks (grana); stroma (fluid) • Contains chlorophylls (pigments) for capturing sunlight energy

49. Illustrative Examples: Variations within molecules provide a wider range of functions: • Chlorophylls

50. Endosymbiont theory • Mitochondria & chloroplasts share similar origin • Prokaryotic cells engulfed by ancestors of eukaryotic cells • Evidence: • Double-membrane structure • Have own ribosomes & DNA • Reproduce independently within cell