1 Photosynthesis Energy & Life

2 Autotrophs Plants and some other types of organisms that contain chlorophyll are able to use light energy from the sun to produce food.

3 Autotrophs Autotrophs include organisms that make their own foodAutotrophs include organisms that make their own food Autotrophs can use the sun’s energy directlyAutotrophs can use the sun’s energy directly Euglena

4 Heterotrophs Heterotrophs are organisms that can NOT make their own foodHeterotrophs are organisms that can NOT make their own food Heterotrophs can NOT directly use the sun’s energyHeterotrophs can NOT directly use the sun’s energy

5 Energy Energy Takes Many Forms such as light, heat, electrical, chemical, mechanicalEnergy Takes Many Forms such as light, heat, electrical, chemical, mechanical Energy can be changed from one form to anotherEnergy can be changed from one form to another Energy can be stored in chemical bonds & then released laterEnergy can be stored in chemical bonds & then released later Candles release energy as HEAT & LIGHT

6 ATP – Cellular Energy Adenosine TriphosphateAdenosine Triphosphate Contains two, high-energy phosphate bondsContains two, high-energy phosphate bonds Also contains the nitrogen base adenine & a ribose sugarAlso contains the nitrogen base adenine & a ribose sugar

7 ADP Adenosine DiphosphateAdenosine Diphosphate ATP releases energy, a free phosphate, & ADP when cells take energy from ATPATP releases energy, a free phosphate, & ADP when cells take energy from ATP One phosphate bond has been removed

8 Sugar in ADP & ATP Called ribose Pentose sugar Also found on RNA

9 Importance of ATP Principal Compound Used To Store Energy In Living Organisms

10 Releasing Energy From ATP ATP is constantly being used and remade by cellsATP is constantly being used and remade by cells ATP provides all of the energy for cell activitiesATP provides all of the energy for cell activities The high energy phosphate bonds can be BROKEN to release energyThe high energy phosphate bonds can be BROKEN to release energy

11 Releasing Energy From ATP Adding A Phosphate Group To ADP stores Energy in ATPAdding A Phosphate Group To ADP stores Energy in ATP Removing A Phosphate Group From ATP Releases Energy & forms ADPRemoving A Phosphate Group From ATP Releases Energy & forms ADP Lose Gain

12 Cells Using Biochemical Energy Cells Use ATP For: Active transport Movement Photosynthesis Protein Synthesis Cellular respiration All other cellular reactions

13 More on ATP Cells Have Enough ATP To Last For A Few SecondsCells Have Enough ATP To Last For A Few Seconds ATP must constantly be madeATP must constantly be made ATP Transfers Energy Very WellATP Transfers Energy Very Well ATP Is NOT Good At Energy StorageATP Is NOT Good At Energy Storage

14 Glucose Glucose is a monosaccharideGlucose is a monosaccharide C 6 H 12 O 6C 6 H 12 O 6 One Molecule of glucose Stores 90 Times More Chemical Energy Than One Molecule of ATPOne Molecule of glucose Stores 90 Times More Chemical Energy Than One Molecule of ATP

15 History of Photosynthesis & Plant Pigments

16 Photosynthesis Is the process that captures energy from the sunlight to convert Water (H 2 0) and Carbon Dioxide (CO 2 ) into Oxygen (O 2 ) and High Energy Carbohydrates (sugars, e.g. Glucose) & StarchesIs the process that captures energy from the sunlight to convert Water (H 2 0) and Carbon Dioxide (CO 2 ) into Oxygen (O 2 ) and High Energy Carbohydrates (sugars, e.g. Glucose) & Starches

17 Investigating Photosynthesis Many Scientists Have Contributed To Understanding PhotosynthesisMany Scientists Have Contributed To Understanding Photosynthesis Early Research Focused On The Overall ProcessEarly Research Focused On The Overall Process Later Researchers Investigated The Detailed Chemical PathwaysLater Researchers Investigated The Detailed Chemical Pathways

18 The Photosynthesis Equation

19 Inside A Chloroplast

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21 Photosynthesis Plants absorb visible light for photosynthesis –Visible light appears white but is made up of several colors

22 Light and Pigments Energy From The Sun Enters Earth’s Biosphere As Photons Photon = Light Energy Unit Light Contains A Mixture Of Wavelengths Different Wavelengths Have Different Colors

23 Light ColorWavelength Red nm (longest) Orange nm Yellow nm Green nm Cyan nm Blue nm Purple nm (shortest)

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26 Pigments In addition to water, carbon dioxide, and light energy, photosynthesis requires Pigments Chlorophyll is the primary light-absorbing pigment in autotrophs Chlorophyll is found inside chloroplasts

27 Chlorophyll There are 2 main types of chlorophyll molecules: Chlorophyll a Chlorophyll b Magnesium atom at the center of chlorophyll

28 Chlorophyll a and b

29 Chlorophyll Together, they absorb mostly red and blue wavelengthsTogether, they absorb mostly red and blue wavelengths They DO NOT absorb the green light (wavelength)They DO NOT absorb the green light (wavelength) The green is reflected, and this is why we see the green!The green is reflected, and this is why we see the green!

30 Pigments Chloroplasts also have another type of pigments called accessory pigments –Appear red, orange, yellow, blue, or scarlet when we see them

31 Pigments Accessory Pigments –Carotenoids-oranges –Xanthophylls-yellows –Anthocyanins-scarlets/reds, lavendars, purples, blues –Tannins-Brown

32 The Colors of Autumn Complete the worksheets!

33 Photosynthesis… occurs in CHLOROPLASTS of plants! Chloroplasts are located in leaf cells that are specialized for photosynthesis

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36 Photosynthesis… Photosynthesis has 2 main stages –Light-Dependent Reactions (require light)—takes place in the thylakoids –Light-Independent Reactions—takes place in the stroma The 2 main parts of chloroplast that are needed for Photosynthesis: –Thylakoids-stack to form a grana –Stroma-the fluid that surrounds the grana inside the chloroplast

37 Light-Dependent Reactions Capture energy from the sunlight Take place within and across the membrane of the thylakoids (that’s where the pigments are—whose job it is to capture light!) Water and sunlight are needed for this stage

38 Light-Dependent Reactions Steps of Light-Dependent Reactions –1. Chlorophyll absorbs energy from sunlight. Water (H 2 0) molecules are broken down. Oxygen (O 2 ) molecules are released –2. Energy is transferred to molecules that carry energy (ATP & NADPH)

Light-Dependent Reactions in Detail The light-dependent reactions include groups of molecules called photosystems. 39

Light Dependent Reactions in Detail Photosystem II captures and transfers energy. –chlorophyll absorbs energy from sunlight –energized electrons enter electron transport chain –water molecules are split –oxygen is released as waste –hydrogen ions are transported across thylakoid membrane (from low to high) 40

Light Dependent Reactions in Detail Photosystem I captures energy and produces energy-carrying molecules. –chlorophyll absorbs energy from sunlight –energized electrons are used to make NADPH –NADPH is transferred to light-independent reactions 41

Light Dependent Reactions in Detail The light-dependent reactions produce ATP. –hydrogen ions flow through a channel in the thylakoid membrane –ATP synthase attached to the channel makes ATP 42

43 Light-Independent Reactions Uses energy from the light-dependent rxn to make sugar Occur in the stroma Carbon dioxide molecules are needed for this stage

Light-Independent Reactions 44 The second stage of photosynthesis uses energy from the first stage to make sugars. Calvin Cycle Dark Reactions

45 Steps of Light-Independent Reaction 1. Carbon Dioxide is added to build larger molecules 2. A molecule of a simple sugar is formed –Usually glucose (C 6 H 12 O 6 ) Stores some of the energy that was captured from the sunlight

Light Independent Reactions (Calvin Cycle) in Detail A molecule of glucose is formed as it stores some of the energy captured from sunlight. –carbon dioxide molecules enter the Calvin cycle –energy is added and carbon molecules are rearranged –a high-energy three-carbon molecule leaves the cycle 46

Light Independent Reactions (Calvin Cycle) in Detail 47

Light Independent Reactions (Calvin Cycle) in Detail A molecule of glucose is formed as it stores some of the energy captured from sunlight. –two three-carbon molecules bond to form a sugar – remaining molecules stay in the cycle 48

49 Photosynthesis Overview

50 Factors Affecting the Rate of Photosynthesis Amount of available waterAmount of available water TemperatureTemperature Amount of available light energyAmount of available light energy