Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Objectives: Summarize how energy is captured from sunlight in the first stage of photosynthesis. Identify three environmental factors that affect the rate of photosynthesis. Plants, algae, some bacteria Capture ~1% of energy from sunlight that reaches Earth Convert this to chemical energy Happens in three stages 1) Energy is captured from sunlight 2) Light energy converted to chemical energy 3) Chemical energy stored in ATP/NADPH powers formation of organic compounds Using light, plants transform CO2 and water into carbohydrates and release oxygen WHERE???? Carbon dioxide WATER _____________ + ____________ 6 CO2 + ____________ 6 H2O _____________ Sugars + ____________ Oxygen __________________ → C6H12O6 + ____________ 6 O2 _______________ 6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2 Required for photosynthesis Found in chloroplasts Chlorophyll** **Primary light-absorbing pigment in autotrophs Carotenoids Yellow, Orange, Red Different wavelengths of light have different colors Different pigments absorb different wavelengths Color of light SEEN is the color NOT absorbed Light Reflected Light Absorbed light Transmitted light Chloroplast GREEN leaves have BOTH chlorophyll AND carotenoids ALL THE TIME __________________ but the huge amount of chlorophyll hides ______ the other colors and leaves usually look green In FALL, chlorophyll production slows as the trees shut down and photosynthesis stops for winter. Then we can see the carotinoid colors that are usually hidden by chlorophyll. © Pearson Education, Inc. Publishing asPearson Prentice-Hall. All rights reserved. There are two types of chlorophyll: Chlorophyll a & Chlorophyll b Absorption of Light by Chlorophyll a and Chlorophyll b Chlorophyll a absorbs the red & ________ violet _____ wavelengths best. Chlorophyll b Chlorophyll a red It absorbs very Blue light. little ______ © Pearson Education, Inc. Publishing asPearson Prentice-Hall. All rights reserved. Absorption of Light by Chlorophyll a and Chlorophyll b Chlorophyll b Chlorophyll a red NEITHER KIND OF CHLOROPHYLL IS VERY GOOD AT ABSORBING GREEN LIGHT! _________ Light hits thylakoids Excites electrons Water molecules fall apart Oxygen is released into air Hydrogen leaves behind ion Excited electrons travel down the electron transport chain (ETC) H+ ions travel out of thylakoid Create ATP (ADP + Pi) OUTSIDE THYLAKOID: Electrons + H join NADP to make NADPH NADPH – provides electrons needed in step 3 a. Overall input: light energy, H2O b. Overall output: ATP, NADPH, O2 http://highered.mcgrawhill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120072/bio13.s wf::Photosynthetic Electron Transport and ATP Synthesis Light Independent Reactions A.K.A. Calvin Cycle or Dark Reactions In Stroma CO2 splits C + O + H (transported by NADPH) form glucose (C6H12O6) Energy from ATP is used to form new bonds a. Overall input: CO2, ATP, NADPH b. Overall output: glucose (after 2 full cycles) • Lack of sufficient water can cause photosynthesis to SLOW or STOP • How does a cactus prevent this? •Enzymes work best at specific temperatures •0-35 °C •Temp too low/high will cause photosynthesis to SLOW or STOP •Conifers??? •More light increases rate of photosynthesis •Up to certain point, until plant reaches max rate Compose a children’s story, song, or poem about the travels of an electron through the light reactions. Be sure to represent ALL the elements of the light reactions in your story. Illustrate a scene from your story which will best represent the activity during the light reactions. Attach your story to your illustration. Question Research? Hypothesis Procedures Results/Data Analysis Conclusions