Ch. 5 Notes Part One: Photosynthesis

DO NOW  1. Which type of diffusion involves the movement of water down the concentration gradient?  2. In which type of environment would a cell potentially burst because the surrounding area had a low concentration of solute, but a high concentration of free water molecules?  3. What does active transport involve (which way are substances pumped across the cell membrane)?

Flow of Energy  Flow of Energy  Sun -- Plants -- Herbivores -- Omnivores / Carnivores -- Decomposers

Ham--> Pigs --> Grains --> Sun Cheese --> Milk --> Cow --> Grass --> Sun Bread --> Wheat --> Sun

Metabolism  Metabolism  Involves building up and breaking down reactions

Metabolism  Photosynthe sis  Light energy is converted to chemical energy

Metabolism  Autotrophs  Use energy from sun or chemical bonds in inorganic substances to make organic compounds  Photosynthetic plants

Metabolism  Heterotrophs  Organisms that must get energy from food instead of directly from the sun

Metabolism  Cellular Respiration  Like burning fuel  Releases much of the energy in food to make ATP

Metabolism  ATP  1. Chemical energy in food slowly released in enzyme assisted reaction  2. Products become reactants for the next reaction  3. Some energy released as heat

Metabolism  ATP  4. Remaining energy temporarily stored as ATP  5. ATP remains available for any chemical reaction in the cell

Metabolism  ATP  6. Made up of a nucleotide with 2 energy storing phosphate groups  7. In all, 5 Carbon sugar with 3 phosphate group chains

Metabolism  ATP  8. Phosphates are negative and repel each other  9. Energy stored in them like compressed springs

Metabolism  ATP  10. Energy released when bond holding phosphate group onto ATP is broken  11. ATP -- ADP + P + Energy

Section 2: Photosynthesis  Photosynthesis  When you eat a hamburger you get energy from the sun INDIRECTLY!  Process by which light energy is converted to chemical energy  Provides energy for almost all life  THINK – PAIR – SHARE  Give the name of the organisms that USE energy from sunlight  Give an example

Photosynthesis  Photosynthesis  EQUATION  Light Energy + 6CO 2 + 6H 2 O ----> C 6 H 12 O 6 + 6O 2  There are 3 stages in Photosynthesis  1. Energy captured from sunlight  2. Light energy converted to chemical energy  3. Organic compounds form

Photosynthesis  Photosynthesis  Think – Pair – Share  Where does photosynthesis occur in plants?  Where does photosynthesis occur in prokaryotes?

Photosynthesis  STAGE ONE-  Absorb Energy from Light  1. Plants have pigments in leaves that absorb light waves  Can you name the primary pigment needed for photosynthesis?  Chlorophyll - types a and b absorbs blues and reds and reflects greens, yellows  Carotenoids- yellow, orange, fall colors (fruits, veggies, flowers)

WHY DO LEAVES TURN COLOR IN THE FALL? THINK – PAIR – SHARE

Photosynthesis  STAGE ONE-  Absorb Energy From Light  2. Oxygen Production in Chloroplasts  A. Chlorophyll is located in the disk shaped stacks called Thylakoids (in chloroplasts)

Photosynthesis  STAGE TWO Conversion of Light Energy  **Turn light energy into chemical energy!**  1. Electron Transport Chains  Excited electrons leave chlorophyll to produce new molecules (ATP!)  Occurs within thylakoid membrane after leaving chlorophyll

Photosynthesis  STAGE TWO Conversion of Light Energy  2. One chain provides energy to make ATP

Photosynthesis  STAGE TWO Conversion of Light Energy  3. Other chain provides energy for making NADPH  NADPH – provides lots of energy to create the organic compounds of photosynthesis  The Hydrogen Ion’s (H+) that come from water provides the energy to make ATP and NADPH in Stage 3

Photosynthesis  STAGE THREE –  Storage of Energy  CARBON DIOXIDE Fixation  1. CO 2 in air used to make organic compounds  2. Calvin Cycle- uses enzymes in a chemical reaction to create 3 carbon sugars = organic compounds  3. Organic Compounds (glucose) provide energy for growth and metabolism

Calvin Cycle

All Three Stages

Photosynthesis  Factors Affecting Photosynthe sis  1. Light intensity  2. Amount of carbon dioxide  3. Temperature  4. Too much of any of these can cause photosynthetic rate to reach a saturation point where it no longer increases

Think – Pair - Share  Factors Affecting Photosynthe sis  Give two factors that could increase the rate of photosynthesis. At what stage would each factor affect?

Click here to visit a website with a photosynthesis interactive: va/methuselah/photosynthe sis.html

Click here to visit a website with a photosynthesis Video Clip: /webcontent/anisamples/maj orsbiology/harvestinglight.s wf