1 / 9

Ch 8- Photosynthesis

Ch 8- Photosynthesis. Animation Quiz - Calvin Cycle Photosynthesis Visualizing Electron Transport Where do plants get the energy they need to produce food? What type of organism makes their own food? What type of organism obtains energy from foods they consume?

becca
Download Presentation

Ch 8- 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. Ch 8- Photosynthesis • Animation Quiz - Calvin Cycle • Photosynthesis • Visualizing Electron Transport • Where do plants get the energy they need to produce food? • What type of organism makes their own food? • What type of organism obtains energy from foods they consume? • ATP (adenosine triphosphate)- basic energy source of all cells, chemical compound that cells use to store and release energy • Adenine, 5- carbon sugar called ribose, and three phosphate groups

  2. ADP (adenosine diphosphatte)- chemical compound similar to ATP, but has two phosphate groups • Key for storing energy • How is the energy that is stored in ATP released? • Chemical bond between second and third phosphate group is broken • Because of the characteristics of ATP, it is an exceptional source of energy

  3. Sec 2- Photosynthesis: An Overview • Photosynthesis- series of reactions that uses light energy from sun to convert water and carbon dioxide into sugars and oxygen • 6 CO₂ + 6 H₂O→ C₆H₁₂O₆+ 6 O₂ • Plants use the sugars to produce complex carbohydrates- starches • In addition to water and carbon dioxide, it requires light and chlorophyll, molecule in chloroplasts

  4. Plants gather the sun’s energy with light absorbing molecules called pigments • Several types of pigments which include; chlorophyll a, chlorophyll b, carotenoids, xanothophylls • Chlorophyll- principal light absorbing pigment • Chlorophyll a and chlorophyll b • Absorbs light very well in certain regions of visible spectrum, green light is reflected • Carotene- red and orange pigments, absorbs light • Chlorophyll b is an accessory pigment that assists in capturing light • Carotenoids are also a accessory pigment that absorbs colors the chlorophylls do not

  5. Sec 3- Reactions in Photosynthesis • Photosynthesis takes place in chloroplasts • Thylakoids- sac-like photosynthetic membranes inside chloroplasts • Arrange in stacks known as grana • Proteins in thylakoids organize chlorophyll into photosystems – 2 types of photosystems • 2 types of reactions in photosystems- light dependent reactions and light independent reactions= Calvin cycle • Light dependent reactions-thylakoid membranes • Calvin cycle= stroma, a region outside thylakoid membranes

  6. Electron Carriers • Sunlight excites electrons in chlorophyll= great deal of energy • Electron carriers transport high energy electrons from chlorophyll to other molecules • NADPᶧ- carrier molecule that accepts and holds 2 high energy electrons along with hydrogen ion • Converts NADPᶧ into NADPH • Allows energy of sunlight to be trapped in chemical form • High energy electrons used to build molecules for cell

  7. Light Dependent Reactions • Requires light • Converts ADP and NADPᶧ into ATP and NADPH and produces oxygen • Steps of light dependent reaction • Light is absorbed by electrons in photosystem II Are electrons ever used up? Where do the electrons come from? • High energy electrons move through electron transport chain to photosystem I • Photosystem I reenergizes electrons released. Electrons are used to form NADPH • Positively charged hydrogen ions fill up thylakoid membrane • Hydrogen ions pass through ATP synthase, ADP is converted into ATP

  8. Calvin Cycle • Plants use energy that ATP and NADPH contain to build high energy compounds • Does not require light, known as light- independent reactions • Steps of Calvin cycle • CO₂ enters the cycle, 6 carbon dioxide molecules combined with six 5 carbon molecules to form twelve 3- carbon molecules • ATP and NADPH are used to convert twelve carbon molecules into higher energy forms • Two 3 carbon molecules removed from cycle to form sugars, lipids, amino acids • 10 remaining 3- carbon molecules converted into six 5- carbon molecules- used in next cycle • Plants use sugars to build cellulose

  9. Factors Affecting Photosynthesis • Factors include water, temperature, and intensity of light • How are plants found in Arizona different from plants in Kansas? • Photosynthesis functions best between 0° and 35° C • Increasing the light intensity increase the rate of photosynthesis, the level of intensity varies among plants

More Related