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Photosynthesis and Respiration. Chapter 6. Photosynthesis. The process by which plants convert the energy of sunlight into the energy of chemical bonds (sugar and starch) Plants make organic compounds (Carbs) from inorganic compounds (Water and CO2). The equation.
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Photosynthesis and Respiration Chapter 6
Photosynthesis • The process by which plants convert the energy of sunlight into the energy of chemical bonds (sugar and starch) • Plants make organic compounds (Carbs) from inorganic compounds (Water and CO2)
The equation • Carbon Dioxide + water sugar + Oxygen • CO2 + H20 C6H12O6 + O2
Sunlight • All organism depend on sunlight for energy • Autotrophs – directly depend on energy to make food • Heterotrophs – indirectly depend on energy because they need to consume autotrophs
Pigments • Colored substances that absorb or reflect light • Capture the light energy to be used by the cell • Found in chloroplasts • Chlorophyll – appears green
Energy storing compounds • When pigments absorb light they boost electrons to a higher energy level • They either are picked up by an electron carrier NADP+ NADPH • Or they are used to make Adenosine Triphosphate (ATP) from AMP or ADP
Complete the following in your purple book • Pg 117 #1-4 and problem solving
DNA RNA (protein Synthesis) Mitosis Meiosis Gregor Mendel Karyotypes and Punnett Suqares Human Genome project Selective breeding (transgenic plants and animals) Sex-linked traits Non-disjunction disorders Mutations Hemophilia & Muscular Dystrophy Kleinfelters and Turner syndrome Dwarfism & Downs Syndrome Genetic Engineering Evolution (Darwin) Project topics
Photosynthesis – the process • Two parts • 1) light reaction – Captures light energy and converts it to stored energy (NADPH or ATP) • Requires sunlight • 2) Dark reaction – used stored energy to convert CO2 into sugar
Light Reaction • Photosynthetic membrane – membrane within the chloroplast • Contains Photosystems –clusters of pigment molecules (both chlorophyll and accessory pigments) • Photosystem I and Photosystem II
When photosystems are hit with sunlight electrons are boosted and released • These electrons are picked up by NADP+ and ADP • These storage molecules will be used to fuel the dark reaction
Electron transport chain (ETC) • In order to be picked up by electron carriers the molecules must pass down the ETC • Electrons released by Chlorophyll will be replaced by the breakdown of water • Oxygen from the breakdown of water is released as waste
Summary of the light reaction • Light hits a photosystem within the chloroplast and boosts the electron level • These electrons are passed down the ETC and picked up by NADP+ and ADP • The electrons are replaced by the breakdown of water • Oxygen is a waste product
???? • What is the formula for photosynthesis? • What are the reactants? • What are the products? • What is the main pigment used in photosynthesis? • What replaces the electrons lost in the light reaction? • What two molecules pick up electrons and take them down the ETC to the dark reaction?
The dark reaction • Light does not play a direct part in the reaction • Also known as the Calvin cycle
Five steps of the Calvin Cycle • 1st - 3(CO2) combines with a 3(5C) molecules and form 3 (6C) molecules • 2nd – The 6C molecules split and make 6 (3C) molecules • 3rd – The molecules rearrange to make 6 (3C) molecules called PGAL • NADPH and ATP are used
4th – 1 PGAL is released and 5 PGAL move on • 5th – the 5 (3C) PGAL molecules rearrange to form 3 (5C) molecules • The cycle repeats
Glycolysis and Respiration • Break down of sugar • Glycolysis – sugar is not completely broken down • Respiration – sugar is completely broken down • C6H12O6 + 6O2 6CO2 + + 6H20
3(CO2) 3(6C) 3(5C) 5 PGAL (3C) 6(3C) 6 PGAL(3C) 1PGAL (3C)
Groups • Names • Topic • Textbook pages • 8-10 facts
Questions?????? • How does the formula for respiration compare to the formula for photosynthesis? • How do they differ in their use/release of energy? • Write this equation using words. • What are the reactants for respiration? • What are the products for respiration?
Glycolysis • Initial breakdown of glucose molecule • 6C sugar is broken down into 2 (3C) PGAL molecules • 2 ATP molecules are needed for this to occur • These two PGAL are then converted to pyruvic acid also a 3C molecule • 4 ATP and 2 NADH are produced • There is a net gain of 2 ATP and 2 NADH
Respiration • If Oxygen is available Respiration will occur • In this process the two pyruvic acid produced during glycolysis are further broken down during the Krebs cycle • This process takes place in the inner membrane of the mitochondria
Steps of the Krebs cycle • 1st – Pyruvic acid (3C) is converted to acetyl-CoA a 2C molecule; 1 CO2 is released • 2nd – the acetyl CoA enters the Krebs cycle and joins with a 4C molecule to create a citric acid a 6C molecule • 3rd – This 6C molecule is converted to a 5 C molecule by releasing 1 CO2 and NADH
4th - This 5C molecule is converted to a 4C molecule by releasing 1 CO2 and NADH • 5th – This 4C molecule is further transformed creating 1GTP, 1 NADH and 1FADH2 • The cycle begins again
Overview of Respiration • 2 Carbon atoms are added in the form of pyruvic acid • 2 Carbon atoms are removed in the from of CO2 • 3 NADH, 1FADH2 and 1 GTP molecules are formed • 2 turns yield 6NADH, 2 FADH2 and 2 GTP
ETC • Electrons from electron carriers (NADH, FADH2 and GTP) are passed down an ETC to form ATP • 1 GTP – 1 ATP • 1 NADH – 3 ATP • 1 FADH2 – 2 ATP
ATP yield Intermediate reaction • 2 NADH – 6 ATP Krebs Cycle • 2 GTP – 2 ATP • 6 NADH – 18 ATP • 2 FADH2 – 4 ATP
Fermentation • If cells do not have Oxygen they can not enter the intermediate step nor the Krebs cycle • They will perform fermentation • Fermentation does not require Oxygen and simply changes pyruvic acid to a more useful
Types of fermentation • Lactic acid fermentation • Muscles • Alcoholic fermentation • Yeast • Uses the NADH produced in glycolysis • Yields 2ATP