1 / 26

Photosynthesis 光合作用

Photosynthesis 光合作用. 香港道教聯合會青松中學 吳友強. Chloroplast under electron microscope. 電子顯微鏡下的葉綠體. Quick Revision : Where does photosynthesis occur ？. Leaf 葉片. X-section 橫切面 : Palisade mesophyll 柵狀葉肉. Chloroplast 葉綠體. Warm-up Questions.

dianne
Télécharger la présentation

Photosynthesis 光合作用

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光合作用 香港道教聯合會青松中學 吳友強

  2. Chloroplast under electron microscope 電子顯微鏡下的葉綠體 Quick Revision : Where does photosynthesis occur？ Leaf 葉片 X-section 橫切面 : Palisade mesophyll 柵狀葉肉 Chloroplast葉綠體

  3. Warm-up Questions The following microphotograph is a transverse section of a A. stem. B. leaf. C. root.

  4. Sorry, you’ve got the wrong answer!!! Can you find cortex (皮層), which is very obvious in a cross-section of a stem ? Try again...

  5. Sorry, you’ve got the wrong answer!!! Are the vascular bundles(維管束)concentrated in the centre of the section ? Try again...

  6. Congratulations!!! You’ve got the correct answer!!! Go to next question...

  7. Warm-up Questions Here is a transverse section of a leaf. It is a leaf of A. monocotyledonousxerophyte B. dicotyledonoushydrophyte C. dicotyledonousmesophyte

  8. Sorry, you’ve got the wrong answer!!! Xerophyte is a kind of plants adapted in desert habitat. Try again...

  9. Sorry, you’ve got the wrong answer!!! Hydrophyte is a kind of plants adapted in aquatic habitat. Try again...

  10. Congratulations!!! You’ve got the correct answer!!! Bonus …….

  11. ??? ??? ??? Bonus : Give two reasons to support your answer. Hints -----

  12. Definition of Photosynthesis Photosynthesis is a process by which green plants use sunlight trapped by chlorophyll to produce organic compounds (carbodyrate) from carbon dioxide and water, oxygen is released as by-product.

  13. Summary of Photosynthesis Sunlight 陽光 Carbon dioxide 二氧化碳 Water 水 Chlorophyll 葉綠素 Oxygen 氧 Glucose 葡萄糖

  14. 6CO2 ＋ 6H2O C6H12O6 + 6O2 chlorophyll Experiments : light 1.To show that starch is produced during Photosynthesis.

  15. Four steps : 1.Boil the leaf in water, why ? 2.Boil the leaf in alcohol, why ? 3.Wash the leaf in warm water, why ? 4.Add iodine solution to the leaf, what is the expected result ?

  16. 6CO2 ＋ 6H2O C6H12O6 + 6O2 chlorophyll Experiments : light Aim : To show that light is necessary for Photosynthesis. Control : Do we need a Control for this experiment ?

  17. 6CO2 ＋ 6H2O C6H12O6 + 6O2 chlorophyll Experiments : light Aim : To show that chlorophyll is necessary for photosynthesis. Control : Do we need a Control for this experiment ? Any Assumption ?

  18. 6CO2 ＋ 6H2O C6H12O6 + 6O2 chlorophyll Experiments : light Aim : To show that carbon dioxide is necessary for photosynthesis. Any Criticism on the set-up ? (Think about Variables.)

  19. 6CO2 ＋ 6H2O C6H12O6 + 6O2 chlorophyll light Is it better ?

  20. 6CO2 ＋ 6H2O C6H12O6 + 6O2 chlorophyll Experiments : light Aim : To show that oxygen is produced during photosynthesis.

  21. Logics In an experiment, think about : Aim and objective Control experiment Dependent variables Independent variables Assumptions Limitations

  22. Limitations of the summary equation :　　 light 6CO2 ＋ 6H2O C6H12O6 + 6O2 chlorophyll 1.Photosynthesis is a two phase process, which cannot be shown in the equation. 2.Source of oxygen cannot be shown. 3.Glucose is not the first product of photosynthesis.

  23. Photosynthesis involves two stages : • Light reaction • light is necessary • light split water into hydrogen and oxygen • Dark reaction • light is not necessary • hydrogen is used to reduce carbon dioxide to carbodyrate

  24. Light reaction Light 陽光 Water 水 Oxygen 氧 Hydrogen氫 （原子） Chlorophyll 葉綠素 Released from the plant Dark reaction

  25. Dark reaction Hydrogen氫 （原子） Carbohydrate 碳水化合物 Carbon dioxide 二氧化碳

  26. This powerpoint was kindly donated to www.worldofteaching.com http://www.worldofteaching.com is home to over a thousand powerpoints submitted by teachers. This is a completely free site and requires no registration. Please visit and I hope it will help in your teaching.

More Related