1. Lesson 3: The Plant Cell...
Teacher: Sven Beer
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2. For this lesson read:
Biology of Plants –
6th ed. pp
7th ed. pp
8th ed. pp
Only text on:
Plastids (chloroplast), vacuole, cell wall and plasmodesmata!
For next lesson read:
Biology of Plants –
6th ed. pp
7th ed. pp
8th ed. pp

3. The Plant Cell
Plasmodesmata

4. The (Plant) Cell…
The Prokaryotic
“Plant” Cell

6. Endosymbiosis
Cyanobacteria
28.2

7. 1: Chloroplasts (plastid)

8. DEMO !!! Chloroplast 1.mov

9. Ulva chloroplasts

11. Chloroplast: The Site of Photosynthesis

12. The Structure of the Chloroplast
Stroma
Granum /
Grana =
Thylakoid stack / stacks

14. The Chlorophyll Structure
Hydrophilic
Hydrophobic

15. Chlorophyll
MW ~ 950
Hydrophilic
Hydrophobic

17. CO2 + H2O >>> CH2O + O2
photo - synthesis
Light Reactions
Carbon Fixation and Reduction
Reactions
(Dark reactions)
stroma
grana
CO2 Fixation

18. Chloroplasts are one form of plastids
Cold
Prolamellar bodies
Etioplast
Light

19. Chloroplasts contain chlorophyll and carotenoids,
in cold: chloroplast can not form chlorophyll and carotenoids bereak down slowly; chromoplast are formed from chloroplasts

20. Plasmodesmata

21. 2: Vacuoles
Vacuoles a) contain waste products; b) keep turgor

22. Waste products, antocyanins
salts

23. Up to 90% of cell volume!

24. Autumn Colors:
Chlorophyll is not formed in the cold – carotenoids break down slowly >> chromoplasts (yellow / orange)
Sugars (and other organic compounds) form antocyanins (red) in the vacuoles

25. red
orange

26. Vascular bundle!
Vascular bundle!
Cell Growth = vacuole expansion / A land plant will wilt in seawater!

27. 3) Cell walls

28. Secretory Vehicles contain: Cellulose, Hemicellulose, Pectin and Glucoproteins

29. Primary wall
Secondary wall
Middle Lamella

30. Macrofibirls>>Microfibrils>>Micelles>>Cellulose

32. Cellulose (more in secondary walls)
cross-linked by Hemicellulose(s) = xyloglucans (glucose + xylose)
Pectins (in primary cell walls only) = hydrophilic
polysaccharides
Glycoproteins (in primary walls)
Lignins (make for stiffness, more in secondary walls)
Cutins, Suberins (cork) and Waxes
Primary wall (while the cell enlarges)
Secondary wall (when the cell has reached its final size)

33. Microfibrils, macrofibrils, lignin, glucoproteins

34. Plasmodesmata

36. Plasmodesmata
Pit

37. Marine Botany
Lesson 3 (cont): The physical and chemical environment relevant to marine plant growth in the oceans…

38. Abiotic = Physical / Chemical Conditions affecting Plant Growth
Light – Irradiance
Temperature
Salinity
Pressure
Currents
pH?

39. Light ?
Photons
Quanta

40. Light, both electromagnetic waves and particles (quanta),
“that trigger nerve impulses from the retina”
Quanta
Photons

41. Leaves are green!
Eye

42. Why are leaves green?
Tomatoes (and Red Algae) red?

43. Visible radiation (= “light”)
Quanta
Photons
Photosynthetically Active Radiation - PAR ( nm)

44. Light, both electromagnetic waves and particles (quanta),
“that trigger nerve impulses from the retina”
Photons
Quanta λ
Quantum E = h*c / λ Photon(s) = quanta ( nm)

45. Chlorophylls absorb light at ~450 and ~670 nm… but how do we know that THIS light drives photosynthesis???

46. Engelmann ~ (1890)

47. Absorption and Action Spectra
Absorption Spectra
Action Spectrum
Engelman -1883
Filament of the
alga Spirogyra

49. Red algae and Cyanobacteria
Chlorophyll
Chlorophyll
Phycobilins

50. Red algae: Complementary chromatic adaptation (?)
Phycobilins

51. Measuring Light (Ft. Candles) (Energy)
Photon Flux (mol photons m-2 s-1); [mol photons = Einstein (E)]
Sunny day: ~ 2000 mmol photons m-2 s-1
Demo

52. Quantum Yield
Absorption vs. Quantum Yield….