PHOTOSYNTHESIS: process which light energy is converted into sugar energy PBS interactive
Major Players in the Development of the Photosynthesis Equation …how did they each contribute? What where their results? Conclusions? Van Helmont: what ingredient makes up plants? Priestly: What are plant byproducts? Ingenhousz: Is light really that important?
Chlorophyll, a green pigment, allows plants to absorb light energy. Energy absorption, however, must be consistent with allowable (basal to excited state) electron transitions within the chlorophyll molecule (click 1). Because these transitions are not continuous, a plant obtains energy only at certain frequencies of light. Energy insufficient to reach an excited state is not absorbed (click 1). Similarly, energy that drives an electron past one energy level but is insufficient to reach a second is not absorbed (click 1). To be absorbed, the energy must be sufficient to reach only allowable energy states (click 1). This simple rule of quantum physics is all you need to know to understand an absorption spectra of chlorophyll (click 1). 300700600500400 Chlorophyll b Absorption Intensity Chlorophyll a excited states ground state 1 2
Chloroplast water O2O2 Sugars CO 2 Light- Dependent Reactions Calvin Cycle NADPH ATP ADP + P NADP + Chloroplast Section 8-3 Figure 8-7 Photosynthesis: An Overview
Photosynthesis H2OH2OH2OH2O CO 2 O2O2O2O2 C 6 H 12 O 6 Light Reaction Dark Reaction Light is Adsorbed ByChlorophyll Which splits water Chloroplast ATP and NADPH 2 ADPNADP Calvin Cycle Energy Used Energy and is recycled. + +
Hydrogen Ion Movement Photosystem II Inner Thylakoid Space Thylakoid Membrane Stroma ATP synthase Electron Transport Chain Photosystem IATP Formation Chloroplast Resources: Photosynthesis animation, VCAC Photosynthesis video, Mastering Biology Light-Dependent Reactions
ChloropIast CO 2 Enters the Cycle Energy Input 5-Carbon Molecules Regenerated Sugars and other compounds 6-Carbon Sugar Produced Section 8-3 Figure 8-11 Calvin Cycle
Comparison of Mitochondria and Chloroplasts Both have a large amount of internal membrane surface area. Both have their own ribosomes. Both have their own genomes. Both produce a large amount of ATP. Both derive energy for ATP synthesis from H + pumps. Both have a large amount of internal membrane surface area. Both have their own ribosomes. Both have their own genomes. Both produce a large amount of ATP. Both derive energy for ATP synthesis from H + pumps.
The mitochondrial genome (in humans) is about 16,000 nucleotides long. The chloroplast genome is about 10x the size of the mitochondrial genome. The mitochondrial genome (in humans) is about 16,000 nucleotides long. The chloroplast genome is about 10x the size of the mitochondrial genome.
Quick Quiz 1.What is the ultimate purpose of photosynthesis? 2.Where does the Calvin Cycle occur? 3.What is the purpose of water? 4.What is the purpose of light? 5.What is the primary raw ingredient of sugar? 6.Where do the Light-Dependent Reactions occur? 7.What makes the turbine spin that makes ATP? 8.What is the waste product of the Light-Dependent Reactions? 9.Why are plants green?
includes of take place in takes place in uses to produce use Section 8-3 Test yourself
Photosynthesis includes of take place in takes place in uses to produce use Light- dependent reactions thylakoidsenergy from sunlight ATPNADPHO2O2 Chloroplasts Section 8-3 Do Now Calvin cycle ATP NADPH High-energy sugars stroma