1 / 26

Photosynthesis

Botany is the study of plants. What characteristics would define a plant?. Photosynthesis. Section 1: Energy and Life. 8.1 Energy and Life. Energy – the ability to do work All living things need chemical energy to survive.

mona-lucas
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. Botany is the study of plants. What characteristics would define a plant? Photosynthesis Section 1: Energy and Life

  2. 8.1 Energy and Life Energy– the ability to do work All living things need chemical energy to survive. The most important molecule cells use to store and release energy is ATP (adenosine triphosphate)

  3. Chemical Energy and ATP • When an organism uses the energy from ATP, the ATP is converted into ADP • ADP (Adenosine Diphosphate ) has only 2 phosphate groups. • Cells can add a phosphate to ADP to make ATP to store energy. (This requires energy) • How is ATP and ADP similar to rechargeable batteries? • Where do YOUR cells get the energy to convert ADP into ATP?

  4. Chemical Energy and ATP How could a small seed gain enough energy to grow into seed a giant tree? Autotroph – uses energy from the sun to produce food Heterotroph – obtains energy from food it consumes

  5. Chemical Energy and ATP

  6. Chemical Energy and ATP Overall Photosynthesis Equation LIGHT 6CO2 + 6H2O C6H12O6 + 6O2 Carbon Dioxide Glucose Oxygen Water Photosynthesis: the process where plants convert energy from the sun into chemical energy stored in the bonds of carbohydrates.

  7. Light and Pigments How are the two types of light different? How are they similar? Light Speed, c = 2.9979 x 108 m/s Or 670.6 million mph

  8. Light and Pigments Electromagnetic Spectrum • Wave length and energy are inversely proportional • The smaller the wave length, the more energy • Which type of light has more energy, the blue or the red? Explain.

  9. Light and Pigments • What colors of light are being absorbed? • What colors of light are being reflected? • What color would the object appear if there was no blue light? • Why are plants usually green?

  10. Spectroscope Lab

  11. Light and Pigments • Pigments – light absorbing molecules • Chlorophyll – the most abundant pigment in plants, that absorbs blue and red light. • Chlorophyll a - a blue-green pigment • Chlorophyll b - a yellow-green pigment

  12. Light and Pigments • Accessory Pigments: pigments other than chlorophyll. • Carotene: orange • Xanthophyll: yellow • Anthocyanin: red • Why do plants need accessory pigments? • They absorb light in other regions of the spectrum • The accessory pigments are always present in most plants but masked by the chlorophyll.

  13. Light and Pigments Answer: Shorter day lengths stop chlorophyll production, and expose accessory pigments Why do leaves change color in the fall?

  14. Photosynthesis: An Overview • Photosynthesis takes place in the chloroplast • Thylakoids – saclike photosynthetic membrane in the chloroplast • Grana – stacks of thylakoids • Stroma - the region outside of the thylakoid membranes

  15. High Energy Electrons • High energy electrons produced by the chlorophyll are highly reactive and need a special carrier • NADP+ accepts a pair of high energy electrons and a hydrogen ion (H+) and carriers them to a chemical reactions elsewhere in the cells. • NADP+ NADPH

  16. Photosynthesis: An Overview Photosynthesis is a complex process that can be broken down into 2 steps:

  17. Light-Dependent Reactions • Occurs in the thylakoid membranes of the chloroplast. • Light energy breaks apart a molecule of H2O • Electrons are energized and used to convert NAD+ into NADH. • Hydrogen ions are used to convert ADP into ATP. • Oxygen is released as a waste product.

  18. Light-Independent Reactions • The NADH and ATP from the light reaction move to the stroma. • The leaf absorbs CO2 from the atmosphere. • The energy from the NADH and ATP is used to convert CO2 into carbohydrates. • What is the main function of carbohydrates?

  19. Light-Independent Reactions • Each molecule of glucose contains enough energy to produce 36 ATP’s. • Plants produce starch when they need to store energy. • Starch is a long chain of glucose.

  20. Photosynthesis and Cell Respiration • Cell Respiration is the opposite of photosynthesis. • What is the equation for photosynthesis? • What is the equation for respiration. • Respiration breaks down carbohydrates into ATP.

  21. Photosynthesis and Cell Respiration • Plants perform both photosynthesis and respiration. • Think: It would pointless to make carbohydrates if you did not break them down into energy.

  22. Factors Affecting Photosynthesis • Water • No enough water means that their will not be enough electrons and H+ to make ATP and NADPH. • Can too much water harm a plant? • Temperature • Too cold: photosynthesis occurs slowly • Too hot: the enzyme that control photosynthesis break down. • Light Intensity • Light is needed to energize the electron from the H2O molecule. • Light that is the wrong color or not intense will slow down photosynthesis.

  23. Short Answer Questions • Explain how the ATP molecule functions similar to rechargeable batteries? (4 points) • Write the overall equation for photosynthesis. (2 points) • Explain why leaves of deciduous trees change color in the fall? (3 points)

  24. Photosynthesis converts includes both (a) (b) (c) to in which in which chemical energy light-excited electrons of chlorophyll CO2 is fixed to RuBP H2O is split and then and reduce NADP+ to (d) are passed down (h) using (f) to produce (e) producing sugar (G3P) (g) by chemiosmosis

  25. Green Solar Cells • What is responsible for the various shades of green in plants? • What is the function of the stromalamellae? • What evidence supports the theory that chloroplast were once invasive cells? • How is excess food stored? • How does the author define photosynthesis?

More Related