260 likes | 328 Vues
Photosynthesis. Plant – multicellular eukaryotes that have cell walls made of cellulose and photosynthesize. Billy. “stationary animals that eat sunlight”. Adenosine Triphosphate (ATP).
E N D
Photosynthesis Plant – multicellular eukaryotes that have cell walls made of cellulose and photosynthesize. Billy “stationary animals that eat sunlight”
Adenosine Triphosphate (ATP) • One of the most important compounds that cells use. Stores and releases energy - adenosine triphosphate (ATP). • ATP consists of adenine, a 5-carbon sugar called ribose, and three phosphate groups.
Adenosine Triphosphate (ATP) • Adenosine diphosphate (ADP) has two phosphate groups instead of three. ADP does not contain as much energy as ATP. Another P is added to ADP to form ATP. • Cells release the energy stored in ATP by breaking the bonds between the second and third phosphate groups.
Uses of ATP • Powers protein pumps in the cell membrane • Powers cilia and flagella • Power for synthesis of proteins • Powers motor proteins that contract muscles • Provides cell energy
Heterotroph – obtains energy from food it consumes How could a small seed become a giant tree? Autotroph – uses energy from the sun to produce food • Photosynthesis - autotrophs use the energy of sunlight to produce high-energy carbohydrates that can be used for food.
Photosynthesis LIGHT 6CO2 + 6H2O C6H12O6 + 6O2 Carbon Dioxide Glucose Water Oxygen
What is Light? Which type of light carries more energy, blue or red? Light Speed, c = 2.9979 x 108 m/s Or 670.6 million mph
Electromagnetic Spectrum • Wave length and energy are inversely proportional • The smaller the wave length, the more energy • Blue light is high energy • Red light is low energy Why are plants usually green? They reflect green light
Plant Pigments • Pigments – light absorbing molecules • Chlorophyll – the most abundant pigment in plants, that absorbs blue and red light. • Chlorophyll a - a blue-green pigment • Chlorophyll b - a yellow-green pigment
Accessory Pigments • Carotene - an orange pigment • Xanthophyll - a yellow pigment • Anthocyanin – a red pigment
Photosynthesis • Takes place in the chloroplast • Thylakoids – saclike photosynthetic membrane in the chloroplast • Grana – stacks of thylakoids • Stroma - the region outside of the thylakoid membranes
H2O CO2 Chloroplast Light NADP+ ADP + P CALVIN CYCLE (in stroma) LIGHT REACTIONS (in thylakoids) ATP Electrons NADPH O Sugar Photosynthesis (Overall) Dark Light
Factors Affecting Photosynthesis • Shortage of water • H2O acts as the electron donor in the light dependent reaction • Temperature • Photosynthesis is controlled by enzymes that work best between 0 C and 35 C. • Light Intensity • More light increases rate of photosynthesis
Light energy O2 CO2 C6H12O6 6 6 H2O ATPs + + 6 + CO2 H2O C6H12O6 O2 6 + 6 + 6 Carbon dioxide Water Glucose Oxygen gas PHOTOSYNTHESIS Carbon dioxide Glucose Energy Oxygen gas Water 0 • Photosynthesis and respiration are complimentary processes. • Products of one are reactants for the other. Photosynthesis Respiration
Organize your thoughts Working in pairs at your tables please address the following: What is the chemical equation for photosynthesis (reactants/products) What is light? How does it play a role in photosynthesis? Write down everything that you already know about photosynthesis. Lastly, what is it that you don’t understand about plants or photosynthesis?
Green Solar Cells • What is responsible for the various shades of green in plants? • What is the function of the stromalamellae? • What evidence supports the theory that chloroplast were once invasive cells? • How is excess food stored? • How does the author define photosynthesis?
5 6 2 4 1 3
H2O CO2 Chloroplast Light NADP+ ADP + P CALVIN CYCLE (in stroma) LIGHT REACTIONS (in thylakoids) ATP Electrons NADPH O Sugar Photosynthesis – Light and Dark Reactions 1 3 Light Dark 2 4
Dark Reaction (Calvin Cycle) 1._______ 3.___________ 2._______________ 4._____________ 5._____________ 6._______ 7._______
Homework (for Thurs. 12/9): • In text read pgs 230-233 • In 8.2 assessment on pg 234 answer question #1,2 and 3 all parts of each question
Using the light reaction diagram: On your own, describe the four steps of the light reaction in your own words. Use complete sentences.
In your group: • See if you can write the chemical equation for photosynthesis (inputs and outputs) • What is the organelle in plant cells that is most involved with photosynthesis • Explain why this organelle captures energy • What is light? • Make a list of things you already know about photosynthesis
Light Reaction 8. H+ Concentration = 10. 4. 7. 9. Type of transport = 5. Type of Transport = 1. 2. 6. H+ Concentration = 3.