1 / 68

PHOTOSYNTHESIS

PHOTOSYNTHESIS. Review Question. Which mode of nutrition do the green plants carry out?. A. Autotrophic nutrition. B. Heterotrophic nutrition. Sorry! You’re wrong!.

addison
Download Presentation

PHOTOSYNTHESIS

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. PHOTOSYNTHESIS

  2. Review Question • Which mode of nutrition do the green plants carry out? A. Autotrophic nutrition B. Heterotrophic nutrition

  3. Sorry! You’re wrong! • Heterotrophic nutrition is the mode of nutrition in which organisms have to depend on other organisms or dead organic matters as their food sources. Green plants, however, can make organic food by themselves using simple inorganic substances. Back

  4. Very Good! • Autotrophic nutrition is the mode of nutrition in which organisms can make organic food by themselves using simple inorganic substances. • The process by which the green plants obtain nutrients is called :- Photosynthesis

  5. Overview of nutrition in green plants carbon dioxide and water photosynthesis mineral salts (e.g. NO3-, SO42-) carbohydrates (e.g. glucose) fatty acids glycerol amino acids water nutrients for plants can be used to produce all plant materials (e.g. enzymes, cell wall, cytoplasm, cell membrane, chlorophyll)

  6. Nature of photosynthesis • Anabolic process • Takes place in chloroplast • Necessary factors : • Carbon dioxide • Water • Sunlight • Chlorophyll

  7. Light

  8. Why leave looked green? Light Absorption Spectrum

  9. Different pigments in absorption spectrum

  10. How light energy used?

  11. Light reaction • Light energy is trapped by chlorophyll in chloroplast

  12. Light reaction Light energy absorbed by chlorophyll splits water molecules into hydrogen and oxygen

  13. Light reaction Oxygen is released as a gas through stoma to outside

  14. Light reaction Hydrogen is fed into dark reaction

  15. Dark reaction Hydrogen produced in light reaction combines with CO2 to form carbohydrates Water is formed as a by-product • No light is required; can take place either in light or darkness

  16. Chlorophyll Structure

  17. Photophosphorylation Light Reaction

  18. Cyclic photophosphorylation

  19. M. Calvin Dark Reaction

  20. Calvin Cycle

  21. CHLOROPLAST

  22. Fate of product of photosynthesis PGAL Pyruvate + coenzyme A X 2 Glucose & Cellulose Kreb cycle Fatty acid Glycerol Nitrate Lipid Protein

  23. Factors affect rate of photosynthesis

  24. Distance Conc. Of NaHCO3 Expt. Show effect of factors Heat

  25. Fate of carbohydrate products in the plant carbon dioxide and water photosynthesis mineral salts (e.g. NO3-, SO42-) carbohydrates (e.g. glucose) fatty acids glycerol amino acids water

  26. Fate of carbohydrate products in the plant carbon dioxide and water photosynthesis mineral salts (e.g. NO3-, SO42-) carbohydrates (e.g. glucose) fatty acids glycerol amino acids water release energy by respiration

  27. Fate of carbohydrate products in the plant carbon dioxide and water photosynthesis mineral salts (e.g. NO3-, SO42-) carbohydrates (e.g. glucose) fatty acids glycerol amino acids water convert into starch for storage

  28. Fate of carbohydrate products in the plant carbon dioxide and water photosynthesis mineral salts (e.g. NO3-, SO42-) carbohydrates (e.g. glucose) fatty acids glycerol amino acids water change into sucrose and is transported to other parts through phloem

  29. Fate of carbohydrate products in the plant carbon dioxide and water photosynthesis mineral salts (e.g. NO3-, SO42-) carbohydrates (e.g. glucose) fatty acids glycerol amino acids water combine to form fats and oils to form cell membranes and as a food store

  30. Fate of carbohydrate products in the plant carbon dioxide and water photosynthesis mineral salts (e.g. NO3-, SO42-) carbohydrates (e.g. glucose) fatty acids glycerol amino acids water join together to become protein molecules

  31. Mineral requirements in plants • In order to synthesize amino acids, nitrate ions must be taken into the plant from the soil through the root • Other minerals are also necessary to maintain the life of the plant

  32. Different Nutrient added Expt. Show effect of minerals

  33. The importance of nitrogen • For synthesis of proteins, chlorophyll, etc. • Taken in the form of nitrate ions • Deficiency symptoms: • Little growth (no protein made) • Yellowing of leaves (chlorophyll made)

  34. The importance of magnesium • Essential component of chlorophyll • Deficiency symptoms: • Yellowing of leaves (no chlorophyll made) • Poor growth (no food manufactured because of lack of chlorophyll)

  35. Use of fertilizers in agriculture • Continuous harvesting crops removes the valuable mineral salts from soil Fertilizers are added to replace such loss • Two kinds of fertilizers: • Natural fertilizers • Chemical fertilizers

  36. Natural fertilizers • From manure • Organic compounds in it are decomposed by bacteria in soil to form mineral salts

  37. Chemical fertilizers • Mainly nitrogenous and phosphorous compounds manufactured artificially

  38. Comparison between natural and chemical fertilizers Natural fertilizers Chemical fertilizers Very cheap More expensive Contain humus which can improve soil texture No humus so cannot improve soil texture Less soluble in water so less likely to be washed away Very soluble in water so more likely to be washed away

  39. Comparison between natural and chemical fertilizers Natural fertilizers Chemical fertilizers Less soluble in water so more difficult to be absorbed Very soluble in water so easier to be absorbed Time is needed for the decomposition to complete before nutrient is available to plants More readily to be used by the plants

  40. Importance of photosynthesis • It is the only method to convert energy in sunlight into chemical energy • Animals have to depend on plants for food supply • Plants: producers; animals : consumers • To maintain a constant oxygen level in the atmosphere

  41. Experiments to test for necessary factors of photosynthesis • Experimental set-up: To remove the factor under study and to see if photosynthesis still takes place • Control set-up: Identical to experimental set-up except that the missing factor is present

  42. A set-up to study whether light is necessary for photosynthesis

  43. Which is the control, the exposed region A or the shaded region B? B? A? A!

  44. What is the purpose of setting up region A? • As a control • Too simple and not explicit! To show that photosynthesis cannot take place in the absence of light

  45. Destarching • Reason: • To avoid any existing starch in the leaves interfering with the result, and to show that any starch found after the experiment was produced during the period of investigation • Method: • By placing the plant in dark for at least 24 hours

  46. Parts of plant where photosynthesis takes place • Places where chloroplasts are found • Mainly in the leaf because • it contains a lot of chloroplasts • it is well adapted for performing photosynthesis

  47. Cross-section of a dicot leaf upper epidermis protect internal tissues from mechanical damage and bacterial and fungal invasion

  48. Cross-section of a dicot leaf • Cuticle • a waxy layer • prevent water loss from the leaf surface

More Related