1 / 43

DO NOW:

DO NOW:. Answer the following question:. A plant was planted six months ago that weighed 12 oz (including the soil) in the window. Now the plant and soil weigh 22 oz!!! How is this possible? (No soil was added, and wet soil does not account for the answer). Plants and Light.

kailey
Download Presentation

DO NOW:

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. DO NOW: Answer the following question: A plant was planted six months ago that weighed 12 oz (including the soil) in the window. Now the plant and soil weigh 22 oz!!! How is this possible? (No soil was added, and wet soil does not account for the answer).

  2. Plants and Light How do plants get their energy? which means? Photosynthesis!!! Using light to make energy. Photo= light Synthesis= to make

  3. 2 Types of organisms… Autotrophs make their own food Heterotrophs must obtain food from environment (eat) What are plants? Autotrophs!!!

  4. 2 Types of Autotrophs… • Photoautotrophs- • Chemoautotrophs- organisms that use light to make food plants bacteria organisms that use chemicals to make food.

  5. Photosynthesis in brief… Plants are autotrophs, relying on photosynthesis to make food (glucose). What’s required for photosynthesis? Light, CO2, and water… …sugar and oxygen are given off

  6. Light Energy!!! Light is a form of radiation, which travels in what are called waves… Let’s see some examples…

  7. wavelength

  8. Smaller wavelength, but greater frequency…

  9. So… Sunlight is a mixture of all visible wavelengths…what color is it? White!!! White light can be broken down into different colors using a prism, which diffracts the light to form a spectrum.

  10. Spectrum? A spectrum is simply a distribution of light, arranged in order according to its energy…

  11. Good Ole Roy!!! How can you remember the colors? Listed backwards, they spell: ROY G. BIV

  12. Why are they arranged this way? It’s due to wavelength… 380 430 500 560 600 750

  13. Why do we see colors? When we see color, it is due to reflected light. This dot, absorbs all light, but that in the red end of the spectrum.

  14. Umm Hmm… Substances that absorb light are called pigments. Umm, what doesn’t absorb light? Anything that’s white!!!

  15. Photosynthetic Pigments By far, the most important pigment in plants, is chlorophyll. All plants have 2 types of chlorophyll: chlorophyll a and chlorophyll b green

  16. Other Pigments Besides chlorophyll, plants have other pigments: carotene (orange) and xanthophyll (yellow)

  17. Pigments continued… Why don’t we see the other pigments? They’re masked by chlorophyll, which is present in great quantities. Why are the other pigments there? They absorb light at different wavelengths than chlorophyll.

  18. Light Reflected Light Chloroplast Absorbed light Granum Transmitted light Figure 10.7

  19. Photosynthesis again… Where does photosynthesis occur? Plants!!! More specifically? Chloroplasts!!!

  20. Anatomy of a Chloroplast: Chloroplasts contain flattened sacs of photosynthetic membranes called thylakoids. A bunch of thylakoids make up grana. The fluid surrounding the grana is called stroma.

  21. Why are chloroplasts necessary? Chlorophyll is contained within the grana… Chlorophyll can absorb energy without stroma present, but it immediately gives off the energy as heat or light.

  22. Necessity of chloroplasts continued. For chlorophyll to produce food for the plant, all of the enzymes contained within the stroma are necessary.

  23. thylakoid stroma grana

  24. Light C6H12O6 + 6O2 + 6H2O 6CO2 + 12H2O Photosynthesis Overall reaction Takes place over many steps…

  25. Photosynthesis Dissected: Divided into 2 types of reactions: • Light-dependent reactions • Light-independent reactions

  26. Light-dependent reactions • Requires light • Take place in the grana of chloroplast • Store energy in high energy molecules • ATP • NADPH

  27. Light Dependent Reactions • Chlorophyll a and b absorb blue-violet and red-orange light from sun and excite electrons • Transfer excited electrons to NADP (carrier) and convert ADP to ATP • Some electrons split water called photolysis • Oxygen is released

  28. NADP+ + H+ + 2e- NADPH ADP 2e- ATP photosystem I 2e- photosystem II 2e- 2H+ + ½ O2 H2O

  29. Excited state e– Heat Energy of election Photon (fluorescence) Ground state Chlorophyll molecule Photon Figure 10.11 A

  30. e– ATP e– e– NADPH e– e– e– Mill makes ATP Photon e– Photon Photosystem I Photosystem II Figure 10.14 

  31. Light-independent Reactions Energy from the light dependent reactions is used to power the light-independent reactions. Do not necessarily occur in the dark, but they don’t require light.

  32. Light-independent continued… Occur in the stroma of the chloroplast Series of enzyme controlled steps to convert CO2 and H into glucose.

  33. The reaction: CO2 goes through a process known as carbon fixation. CO2 reacts with a 5 carbon sugar called ribulose bisphosphate (RuBP), and then enters the Calvin Cycle

  34. Light Independent Reactions • H from NAPH2 from light reactions • Carbon dioxide from environment • Require products from light reactions so stop shortly after light reactions end • Water is also a by-product

  35. Light reaction Calvin cycle H2O CO2 Light NADP+ ADP + P 1 RuBP 3-Phosphoglycerate Photosystem II Electron transport chain Photosystem I ATP G3P Starch (storage) NADPH Figure 10.21 Amino acids Fatty acids Chloroplast O2 Sucrose (export) Calvin cycle reactions: • Take place in the stroma • Use ATP and NADPH to convert CO2 to the sugar G3P • Return ADP, inorganic phosphate, and NADP+ to the light reactions Light reactions: • Are carried out by molecules in the thylakoid membranes • Convert light energy to the chemical energy of ATP and NADPH • Split H2O and release O2 to the atmosphere

  36. Factors influencing photosynthesis: There are 3 main factors influencing the rate: • Light intensity • Temperature • Water and mineral availability • Carbon dioxide level

  37. Photosynthesis vs Cellular Respiration In brief, they are exact opposites: photosynthesis stores energy in glucose, respiration releases energy.

  38. Photosynthesis vs Cellular Respiration Photosynthesis: Light 6CO2 + 12H2O C6H12O6 + 6O2 + 6H2O

  39. Photosynthesis vs Cellular Respiration Photosynthesis: Light 6CO2 + 12H2O C6H12O6 + 6O2 + 6H2O Respiration: C6H12O6 + 6O2 + 6H2O 6CO2 + 12H2O

  40. Leaf cross section Vein Mesophyll CO2 O2 Stomata Figure 10.3

More Related