Photosynthesis: Light Reaction Events PDF

LESSON 2.1 PHOTOSYNTHESIS: LIGHT REACTION EVENTS  Unpacked Objectives Content Standards At the end of the lesson students will be able to: ATP-ADP Cycle, Photosynt...

LESSON 2.1 PHOTOSYNTHESIS: LIGHT REACTION EVENTS  Unpacked Objectives Content Standards At the end of the lesson students will be able to: ATP-ADP Cycle, Photosynthesis and Respiration. Describe the patterns of electron flow through light reaction events. Complete the electron transport chain diagram for light-dependent Learning Competencies reactions. Recognize the importance of light- dependent reactions of Describe the patterns of electron photosynthesis in living things. flow through light reaction events Create a diagram of light-dependent (STEM_BIO11/12-IIa-j-1) reactions.  Let’s review Phosphorylation and hydrolysis is a coupled reaction. Based upon the role of ATP within cells, what type of reactions are ATP hydrolysis and ADP phosphorylation? What is the role of ATP synthase in the electron transport chain? Let’s review Spot Me! Chlorophyll Chlorophyll absorbs The primary pigment light most efficiently in plants and other in the blue and red photosynthetic parts of the organisms and is electromagnetic crucial for spectrum. photosynthesis. It's what gives plants their green color.  What is the Tell me: reason why most plants appear green?  Chlorophyll and other pigments are crucial for photosynthesis, the Chlorophyll process by which plants and some other organisms convert light energy into chemical energy. Chlorophyll How important these pigments?  Light absorption: Chlorophyll absorbs Importance light energy, primarily in the blue and red parts of the visible spectrum.  Energy conversion: It converts light energy Importance into chemical energy, which is used to produce glucose from carbon dioxide and water.  Oxygen production: As a byproduct of Importance photosynthesis, oxygen is released, which is vital for most life on Earth.  They play a role in Importance photoprotection, helping plants deal with excess light energy.  In many plants, they contribute to flower and fruit colors, Importance which can be important for attracting pollinators and seed dispersers.  Other pigments There are several types of chlorophyll (a, b, c, d), with chlorophyll a being While chlorophyll is the most abundant and well- the most common and known pigment, plants crucial for the light- contain other pigments dependent reactions of as well. photosynthesis.  This is the most common and important form of chlorophyll. It's found in all Chlorophyll a photosynthetic plants, algae, and cyanobacteria. Chlorophyll a absorbs light most efficiently at wavelengths of 430 nm (blue) and 662 nm (red).  This type is found in plants and green algae, alongside chlorophyll a. It absorbs light at slightly different Chlorophyll b wavelengths (453 nm and 642 nm), complementing chlorophyll a and expanding the range of light that can be used for photosynthesis.  This type is found in various algae, particularly brown algae and diatoms. It's not Chlorophyll c present in land plants. Chlorophyll c actually comprises several subtypes (c1, c2, c3).  This rare form of chlorophyll is found in some red algae and cyanobacteria. It can use far- red light (700-750 nm) for Chlorophyll d photosynthesis, allowing organisms to photosynthesize in deep water where only longer wavelengths of light penetrate.  This is a less common form of chlorophyll, Chlorophyll e found in some golden algae. It's structurally similar to chlorophyll c.  Discovered relatively recently (in 2010), chlorophyll f is found in Chlorophyll f some cyanobacteria. Like chlorophyll d, it can use far-red light for photosynthesis.  This is the most recently discovered type of chlorophyll (in 2020). It was Chlorophyll g found in a strain of cyanobacteria and, like chlorophylls d and f, it can use far-red light for photosynthesis.  What do you think would be the Tell me: significance of chlorophylls a, b, c, d, e, f and g?  Importance These different types of chlorophyll allow various photosynthetic organisms to adapt to different light conditions and ecological niches. For instance, the ability of chlorophylls d, f, and g to use far-red light allows certain cyanobacteria to photosynthesize in environments where other organisms cannot, such as in deep water or under the canopy of other plants.  They absorb light at different Accessory wavelengths than chlorophyll, Pigments expanding the range of light that can be used for photosynthesis. Accessory They help protect the Pigments photosynthetic apparatus from damage by excess  In some cases, they can transfer Accessory absorbed energy to Pigments chlorophyll, enhancing overall photosynthetic efficiency.  Colors: Yellow, orange, and red Carotenoids Examples: Beta- carotene, lycopene, xanthophylls Carotenoids Photoprotection: They help protect the plant from damage Importance caused by excessive light energy.  Light harvesting: They Carotenoids can absorb light at wavelengths that chlorophyll cannot, expanding the range Importance of light used for photosynthesis. Carotenoids Antioxidants: Many carotenoids act as antioxidants, protecting the Importance plant from oxidative stress.  Colors: Red, purple, and Anthocyanins blue Found in: Flowers, fruits, and autumn leaves Anthocyanins UV protection: They can help shield plant tissues from harmful Importance UV radiation. Anthocyanins Attract pollinators and seed dispersers: Bright colors in flowers and Importance fruits can attract animals. Anthocyanins Cold tolerance: In some plants, anthocyanins may help with cold Importance tolerance.  Colors: Red and blue Phycobilins Found in: Algae and cyanobacteria  Expand light absorption: Phycobilins They allow these organisms to carry out photosynthesis in deeper Importance water where only certain wavelengths of light penetrate.  Efficient light harvesting: Different The diversity of pigments absorb pigments in plants light at different serves several wavelengths, important allowing plants to functions: utilize more of the available light energy.  Adaptation to The diversity of different pigments in plants environments: Plants serves several can adapt to various important light conditions by functions: adjusting their pigment composition.  Protection: Some The diversity of pigments protect pigments in plants against excessive light serves several energy or UV important radiation. functions:  Signaling: Pigments play The diversity of a role in attracting pigments in plants pollinators and seed serves several dispersers, which is important crucial for plant functions: reproduction.  The diversity of Seasonal adaptation: pigments in plants Changes in pigmentation serves several (like autumn leaves) can important help plants prepare for functions: different seasons.  They expand the plant's ability to harvest light, Now you know protect it from environmental stresses, and aid in various Chlorophyll is the star ecological interactions. player in This diversity of pigments photosynthesis, the contributes to the other pigments play resilience and vital supporting roles. adaptability of plants in different environments. Now you know This diversity also reflects The diversity of chlorophyll the evolutionary history of types highlights the photosynthetic organisms, adaptability of with different types of photosynthetic organisms chlorophyll evolving to suit and their ability to thrive in various environments by different ecological making use of different conditions. parts of the light spectrum. THANK YOU