1 Photosynthesis Energy & Life Pre-ap biology

Objectives- Standard 7 Students will be able to Explain how an ATP molecule can gain or loose energy Understand how specific organisms gain their energy. 2

Objectives- Standard 8 Students will be able to: Describe how the reactants are used in photosynthesis, and how they affect the products. Analyze the energy pathway in photosynthesis. Explain how environmental factors may affect the rate of photosynthesis 3

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

5 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

6 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

7 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

8 ATP – Cellular Energy ATP is how cells store and use energyATP is how cells store and use energy ATP= Adenosine TriphosphateATP= Adenosine 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

9 ADP ADP=Adenosine DiphosphateADP=Adenosine Diphosphate ATP releases energy, a free phosphate, & becomes ADP when cells take energy from ATPATP releases energy, a free phosphate, & becomes ADP when cells take energy from ATP ATP releases energy when one phosphate bond has been removedATP releases energy when one phosphate bond has been removed One phosphate bond has been removed

10 Why is ATP important? Principal Compound Used To Store Energy In Living Organisms

11 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 The process of releasing ATP’s energy & reforming the molecule is called phosphorylationThe process of releasing ATP’s energy & reforming the molecule is called phosphorylation

12 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 Loose Gain

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 But ATP Is NOT Good At Energy Storage.But ATP Is NOT Good At Energy Storage. So…So…

14 Glucose Glucose is a carbohydrateGlucose is a carbohydrate 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 Cells Using Biochemical Energy Cells Use ATP For: Active transport Movement within a cell Photosynthesis Protein Synthesis Cellular respiration All other cellular reactions

16 Photosynthesis & Plant Pigments

17 Photosynthesis Involves the Use Of light energy to convert Water (H 2 0) and Carbon Dioxide (CO 2 ) into Oxygen (O 2 ) and High Energy Carbohydrates (sugars, like Glucose & Starches)Involves the Use Of light energy to convert Water (H 2 0) and Carbon Dioxide (CO 2 ) into Oxygen (O 2 ) and High Energy Carbohydrates (sugars, like Glucose & Starches)

18 The Photosynthesis Equation

19 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

Light and Pigments The pigments of photosynthesis absorb red and blue light, and reflect green light That is why leaves appear green! 20

21 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

22 Light & Pigments Photons of light “excite” electrons in the plant’s pigmentsPhotons of light “excite” electrons in the plant’s pigments Excited electrons carry the absorbed energyExcited electrons carry the absorbed energy Excited electrons move to HIGHER energy levels Excited electrons move to HIGHER energy levels

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