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Photosynthesis.pptx

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shivaveerakumar kumar

The document discusses microbial photosynthesis and the process of photosynthesis in plants. It begins by explaining that the sun is the main source of energy for life on Earth and provides details about its composition and layers. It then describes how photosynthesis uses light energy from the sun to convert carbon dioxide and water into glucose and oxygen through two stages - the light-dependent reactions and the Calvin cycle. The light reactions generate ATP and NADPH using energy from sunlight, while the Calvin cycle uses these products to incorporate carbon from carbon dioxide into organic molecules to form glucose.

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Microbial Photosynthesis Shivaveerakumar S.
THE SUN: MAIN SOURCE OF ENERGY FOR LIFE ON EARTH
Our Star, the Sun
The Sun is the Largest Object in the Solar System The Sun contains more than 99.85% of the total mass of the solar system If you put all the planets in the solar system, they would not fill up the volume of the Sun 110 Earths or 10 Jupiter's fit across the diameter of the Sun
The Sun goes through periods of relative activity and inactivity
The Suns interior has three layers: (1) Core (2) Radiative zone (3) Convective zone Energy generated in the core of the sun propagates outward through these different layers, and finally, through the atmosphere of the Sun. This process takes tens of thousands of years or more.
Like most stars, the sun is made up mostly of hydrogen and helium atoms in a plasma state. The sun generates energy from a process called nuclear fusion. During nuclear fusion, the high pressure and temperature in the sun's core cause nuclei to separate from their electrons. Solar energy is any type of energy generated by the sun. Solar energy is created by nuclear fusion that takes place in the sun. Fusion occurs when protons of hydrogen atoms violently collide in the sun's core and fuse to create a helium atom. Like the Earth, the sun has layers. But unlike the Earth, the sun is entirely gaseous; there is no solid surface. Sun provides two types of energy: Heat and Light.
Also known as light energy or electromagnetic energy, radiant energy is a type of kinetic energy that travels in waves. Examples include the energy from the sun, x-rays, and radio waves. The energy from the sun that reaches the earth arrives as solar radiation, part of a large collection of energy called the electromagnetic radiation spectrum. Solar radiation includes visible light, ultraviolet light, infrared, radio waves, X-rays, and gamma rays. 4 types of sun's radiation include: Infrared rays, Visible rays. Ultraviolet light. Radio waves.
The Sun's diameter is about 1.39 million kilometers (864,000 miles), or 110 times that of Earth. Its mass is about 3,30,000 times that of Earth, comprising about 99.86% of the total mass of the Solar System. Roughly three-quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron. The sun has extremely important influences on our planet. It drives weather, ocean currents, seasons, and climate, and makes plant life possible through photosynthesis. Without the sun's heat and light, life on Earth would not exist.
Sunlight or Energy of Sun: Improves your sleep. Your body creates a hormone called melatonin that is critical to helping you sleep. Reduces stress. Maintains strong bones. Helps keep the weight off. Strengthens your immune system. Fights off depression. Can give you a longer life. Deficiencies could increase the risk for osteoporosis, heart disease, some cancers, infectious diseases and even the flu.
Sunlight also helps our skin make vitamin D, which is needed for normal bone function and health. Yet sunlight can also cause damage. Sunlight travels to Earth as a mixture of both visible and invisible rays, or waves. Long waves, like radio waves, are harmless to people. Regular sun exposure is the most natural way to get enough vitamin D. To maintain healthy blood levels, aim to get 1030 minutes of midday sunlight, several times per week. People with darker skin may need a little more than this. Your exposure time should depend on how sensitive your skin is to sunlight.
Deficient of sunlight, all plants would die and, eventually, all animals that rely on plants for food including humans would die, too. While some inventive humans might be able to survive on a Sun-less Earth for several days, months, or even years, life without the Sun would eventually prove to be impossible to maintain on Earth. About 5 billion years, the sun will run out of hydrogen. Our star is currently in the most stable phase of its life cycle and has been since the formation of our solar system, about 4.5 billion years ago. Once all the hydrogen gets used up, the sun will grow out of this stable phase.
Almost all plants are photosynthetic autotrophs, as are some bacteria and protists Autotrophs generate their own organic matter through photosynthesis Sunlight energy is transformed to energy stored in the form of chemical bonds (a) Mosses, ferns, (b) and flowering plants (b) Kelp (c) Euglena (d) Cyanobacteria THE BASICS OF PHOTOSYNTHESIS
Light Energy Harvested by Plants & Other Photosynthetic Autotrophs 6 CO2 + 6 H2O + light energy C6H12O6 + 6 O2
Photosynthesis is the process by which autotrophic organisms use light energy to make sugar and oxygen gas from carbon dioxide and water AN OVERVIEW OF PHOTOSYNTHESIS Carbon dioxide Water Glucose Oxygen gas PHOTOSYNTHESIS
The Calvin cycle makes sugar from carbon dioxide ATP generated by the light reactions provides the energy for sugar synthesis The NADPH produced by the light reactions provides the electrons for the reduction of carbon dioxide to glucose Light Chloroplast Light reactions Calvin cycle NADP ADP + P The light reactions convert solar energy to chemical energy Produce ATP & NADPH AN OVERVIEW OF PHOTOSYNTHESIS
Chloroplasts: Sites of Photosynthesis Photosynthesis Occurs in chloroplasts, organelles in certain plants All green plant parts have chloroplasts and carry out photosynthesis The leaves have the most chloroplasts The green color comes from chlorophyll in the chloroplasts The pigments absorb light energy
In most plants, photosynthesis occurs primarily in the leaves, in the chloroplasts A chloroplast contains: Stroma, a fluid Grana, stacks of thylakoids The thylakoids contain chlorophyll Chlorophyll is the green pigment that captures light for photosynthesis Photosynthesis occurs in chloroplasts
General Mechanism of Bacterial Photosynthesis Light-harvesting pigments (LHPs) embedded in membranes capture light energy and transfer it to a protein-complex called a reaction center The energy is converted into excited, low potential electrons Electrons are fed into an electron transport chain, where they "fall" through a series of electron carriers, generating a proton motive force (PMF) Membrane-bound ATPases then use the proton motive force to make ATP.
Classification of Photosynthetic Bacteria Five photosynthetic groups within domain Bacteria (based on 16S rRNA) Oxygenic Photosynthesis Cyanobacteria and Prochlorophytes Anoxygenic Photosynthesis Purple bacteria Green sulfur bacteria Heliobacteria Green gliding bacteria
Oxygenic Photosynthesis Occurs in Cyanobacteria and Prochlorophytes Synthesis of carbohydrates results in release of molecular O2 and removal of CO2 from atmoshphere Occurs in lamallae which house thylakoids containing chlorophyll a/b and phycobilisomes pigments which gather light energy Uses two photosystems (PS): - PS II- generates a proton-motive force for making ATP - PS I- generates low potential electrons for reducing power.
Oxygenic Photosynthesis
Anoxygenic Photosynthesis Uses light energy to create organic compounds, and sulfur or fumarate compounds instead of O2 Occurs in purple bacteria, green sulfur bacteria, green gliding bacteria and heliobacteria Uses bacteriochlorophyll pigments instead of chlorophyll Uses one photosystem (PS I) to generate ATP in cyclic manner
Anoxygenic Photosynthesis Reduction potential: A tendency of a chemical species to be reduced by gaining an electron
Chloroplasts contain several pigments Chloroplast Pigments Chlorophyll a Chlorophyll b Carotenoids Figure 7.7
Chlorophyll a & b Chl a has a methyl group Chl b has a carbonyl group Porphyrin ring delocalized e- Phytol tail Phytol tail of chlorophyll is a long hydrocarbon chain that is hydrophobic in nature. It anchors the pigment to membranes of thylakoids. The hydrophobicity of the tail allows it to anchor the pigment to the membranes of thylakoids. Mg ion is present in the Porphyrin head.
Different pigments absorb light differently
Excited state e Heat Light Photon Light (fluorescence) Chlorophyll molecule Ground state 2 (a) Absorption of a photon Excitation of chlorophyll in a chloroplast e Photolysis of water: When the electrons leave the chlorophyll molecules, it leaves behind a 'hole.' This electron hole is filled in by a water molecule that is oxidized, or loses electrons, as it essentially splits into two hydrogen atoms, or protons, and an oxygen atom.
Cyclic Photophosphorylation Process for ATP generation associated with some Photosynthetic Bacteria Reaction Center => 700 nm
Water-splitting photosystem NADPH-producing photosystem ATP mill Two types of photosystems cooperate in the light reactions
Primary electron acceptor Primary electron acceptor Photons PHOTOSYSTEM I PHOTOSYSTEM II Energy for synthesis of by chemiosmosis Noncyclic Photophosphorylation Photosystem II regains electrons by splitting water, leaving O2 gas as a by-product
The O2 liberated by photosynthesis is made from the oxygen in water (H+ and e-) Plants produce O2 gas by splitting H2O
2 H + 1/2 Water-splitting photosystem Reaction- center chlorophyll Light Primary electron acceptor Energy to make Primary electron acceptor Primary electron acceptor NADPH-producing photosystem Light NADP 1 2 3 How the Light Reactions Generate ATP and NADPH
Two connected photosystems collect photons of light and transfer the energy to chlorophyll electrons The excited electrons are passed from the primary electron acceptor to electron transport chains Their energy ends up in ATP and NADPH In the light reactions, electron transport chains generate ATP, NADPH, & O2
The electron transport chains are arranged with the photosystems in the thylakoid membranes and pump H+ through that membrane The flow of H+ back through the membrane is controlled by ATP synthase to make ATP In the stroma, the H+ ions combine with NADP+ to form NADPH Chemiosmosis powers ATP synthesis in the light reactions
The production of ATP by chemiosmosis in photosynthesis Thylakoid compartmen t (high H+) Thylakoid membrane Stroma (low H+) Light Antenna molecules Light ELECTRON TRANSPORT CHAIN PHOTOSYSTEM II PHOTOSYSTEM I ATP SYNTHASE
Review: Photosynthesis uses light energy to make food molecules Light Chloroplast Photosystem II Electron transport chains Photosystem I CALVIN CYCLE Stroma LIGHT REACTIONS CALVIN CYCLE Cellular respiration Cellulose Starch Other organic compounds A summary of the chemical processes of photosynthe sis
Dark reaction (Light-independent Reaction) 6CO2 + 12H2O + light energy C6H12O6 + 6O2 + 6H2O Dark reaction: Calvin cycle regenerative anabolic CO2 in, sugar out during daylight CO2 NADP+ ADP Pi + RuBP 3-Phosphoglycerate Calvin Cycle G3P ATP NADPH Starch (storage) Sucrose (export) Chloroplast Light H2O O2
Carbon fixation 3 stages of Calvin- cycle: #1 carbon fixation CO2 link to 5-C 5-C: ribulose bisphosphate (RuBP) - enzyme: Rubisco abundant 6-C unstable split 2(3-C)
Reduction #2 reduction reduced 3-C: G3P 3-C reduced e- from NADPH 3 stages of Calvin- cycle:
Regeneration of C-acceptor multiple steps uses ATP every 3 cycles: 1 G3P made 3 RuBP regenerated #3 regenerate C- acceptor still 5 G3P 3 RuBP C3 plants CO2 fixed into 3-C 3 stages of Calvin- cycle:

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Photosynthesis.pptx

  • 2. THE SUN: MAIN SOURCE OF ENERGY FOR LIFE ON EARTH
  • 4. The Sun is the Largest Object in the Solar System The Sun contains more than 99.85% of the total mass of the solar system If you put all the planets in the solar system, they would not fill up the volume of the Sun 110 Earths or 10 Jupiter's fit across the diameter of the Sun
  • 5. The Sun goes through periods of relative activity and inactivity
  • 6. The Suns interior has three layers: (1) Core (2) Radiative zone (3) Convective zone Energy generated in the core of the sun propagates outward through these different layers, and finally, through the atmosphere of the Sun. This process takes tens of thousands of years or more.
  • 7. Like most stars, the sun is made up mostly of hydrogen and helium atoms in a plasma state. The sun generates energy from a process called nuclear fusion. During nuclear fusion, the high pressure and temperature in the sun's core cause nuclei to separate from their electrons. Solar energy is any type of energy generated by the sun. Solar energy is created by nuclear fusion that takes place in the sun. Fusion occurs when protons of hydrogen atoms violently collide in the sun's core and fuse to create a helium atom. Like the Earth, the sun has layers. But unlike the Earth, the sun is entirely gaseous; there is no solid surface. Sun provides two types of energy: Heat and Light.
  • 8. Also known as light energy or electromagnetic energy, radiant energy is a type of kinetic energy that travels in waves. Examples include the energy from the sun, x-rays, and radio waves. The energy from the sun that reaches the earth arrives as solar radiation, part of a large collection of energy called the electromagnetic radiation spectrum. Solar radiation includes visible light, ultraviolet light, infrared, radio waves, X-rays, and gamma rays. 4 types of sun's radiation include: Infrared rays, Visible rays. Ultraviolet light. Radio waves.
  • 9. The Sun's diameter is about 1.39 million kilometers (864,000 miles), or 110 times that of Earth. Its mass is about 3,30,000 times that of Earth, comprising about 99.86% of the total mass of the Solar System. Roughly three-quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron. The sun has extremely important influences on our planet. It drives weather, ocean currents, seasons, and climate, and makes plant life possible through photosynthesis. Without the sun's heat and light, life on Earth would not exist.
  • 10. Sunlight or Energy of Sun: Improves your sleep. Your body creates a hormone called melatonin that is critical to helping you sleep. Reduces stress. Maintains strong bones. Helps keep the weight off. Strengthens your immune system. Fights off depression. Can give you a longer life. Deficiencies could increase the risk for osteoporosis, heart disease, some cancers, infectious diseases and even the flu.
  • 11. Sunlight also helps our skin make vitamin D, which is needed for normal bone function and health. Yet sunlight can also cause damage. Sunlight travels to Earth as a mixture of both visible and invisible rays, or waves. Long waves, like radio waves, are harmless to people. Regular sun exposure is the most natural way to get enough vitamin D. To maintain healthy blood levels, aim to get 1030 minutes of midday sunlight, several times per week. People with darker skin may need a little more than this. Your exposure time should depend on how sensitive your skin is to sunlight.
  • 12. Deficient of sunlight, all plants would die and, eventually, all animals that rely on plants for food including humans would die, too. While some inventive humans might be able to survive on a Sun-less Earth for several days, months, or even years, life without the Sun would eventually prove to be impossible to maintain on Earth. About 5 billion years, the sun will run out of hydrogen. Our star is currently in the most stable phase of its life cycle and has been since the formation of our solar system, about 4.5 billion years ago. Once all the hydrogen gets used up, the sun will grow out of this stable phase.
  • 13. Almost all plants are photosynthetic autotrophs, as are some bacteria and protists Autotrophs generate their own organic matter through photosynthesis Sunlight energy is transformed to energy stored in the form of chemical bonds (a) Mosses, ferns, (b) and flowering plants (b) Kelp (c) Euglena (d) Cyanobacteria THE BASICS OF PHOTOSYNTHESIS
  • 14. Light Energy Harvested by Plants & Other Photosynthetic Autotrophs 6 CO2 + 6 H2O + light energy C6H12O6 + 6 O2
  • 15. Photosynthesis is the process by which autotrophic organisms use light energy to make sugar and oxygen gas from carbon dioxide and water AN OVERVIEW OF PHOTOSYNTHESIS Carbon dioxide Water Glucose Oxygen gas PHOTOSYNTHESIS
  • 16. The Calvin cycle makes sugar from carbon dioxide ATP generated by the light reactions provides the energy for sugar synthesis The NADPH produced by the light reactions provides the electrons for the reduction of carbon dioxide to glucose Light Chloroplast Light reactions Calvin cycle NADP ADP + P The light reactions convert solar energy to chemical energy Produce ATP & NADPH AN OVERVIEW OF PHOTOSYNTHESIS
  • 17. Chloroplasts: Sites of Photosynthesis Photosynthesis Occurs in chloroplasts, organelles in certain plants All green plant parts have chloroplasts and carry out photosynthesis The leaves have the most chloroplasts The green color comes from chlorophyll in the chloroplasts The pigments absorb light energy
  • 18. In most plants, photosynthesis occurs primarily in the leaves, in the chloroplasts A chloroplast contains: Stroma, a fluid Grana, stacks of thylakoids The thylakoids contain chlorophyll Chlorophyll is the green pigment that captures light for photosynthesis Photosynthesis occurs in chloroplasts
  • 19. General Mechanism of Bacterial Photosynthesis Light-harvesting pigments (LHPs) embedded in membranes capture light energy and transfer it to a protein-complex called a reaction center The energy is converted into excited, low potential electrons Electrons are fed into an electron transport chain, where they "fall" through a series of electron carriers, generating a proton motive force (PMF) Membrane-bound ATPases then use the proton motive force to make ATP.
  • 20. Classification of Photosynthetic Bacteria Five photosynthetic groups within domain Bacteria (based on 16S rRNA) Oxygenic Photosynthesis Cyanobacteria and Prochlorophytes Anoxygenic Photosynthesis Purple bacteria Green sulfur bacteria Heliobacteria Green gliding bacteria
  • 21. Oxygenic Photosynthesis Occurs in Cyanobacteria and Prochlorophytes Synthesis of carbohydrates results in release of molecular O2 and removal of CO2 from atmoshphere Occurs in lamallae which house thylakoids containing chlorophyll a/b and phycobilisomes pigments which gather light energy Uses two photosystems (PS): - PS II- generates a proton-motive force for making ATP - PS I- generates low potential electrons for reducing power.
  • 23. Anoxygenic Photosynthesis Uses light energy to create organic compounds, and sulfur or fumarate compounds instead of O2 Occurs in purple bacteria, green sulfur bacteria, green gliding bacteria and heliobacteria Uses bacteriochlorophyll pigments instead of chlorophyll Uses one photosystem (PS I) to generate ATP in cyclic manner
  • 24. Anoxygenic Photosynthesis Reduction potential: A tendency of a chemical species to be reduced by gaining an electron
  • 25. Chloroplasts contain several pigments Chloroplast Pigments Chlorophyll a Chlorophyll b Carotenoids Figure 7.7
  • 26. Chlorophyll a & b Chl a has a methyl group Chl b has a carbonyl group Porphyrin ring delocalized e- Phytol tail Phytol tail of chlorophyll is a long hydrocarbon chain that is hydrophobic in nature. It anchors the pigment to membranes of thylakoids. The hydrophobicity of the tail allows it to anchor the pigment to the membranes of thylakoids. Mg ion is present in the Porphyrin head.
  • 27. Different pigments absorb light differently
  • 28. Excited state e Heat Light Photon Light (fluorescence) Chlorophyll molecule Ground state 2 (a) Absorption of a photon Excitation of chlorophyll in a chloroplast e Photolysis of water: When the electrons leave the chlorophyll molecules, it leaves behind a 'hole.' This electron hole is filled in by a water molecule that is oxidized, or loses electrons, as it essentially splits into two hydrogen atoms, or protons, and an oxygen atom.
  • 29. Cyclic Photophosphorylation Process for ATP generation associated with some Photosynthetic Bacteria Reaction Center => 700 nm
  • 30. Water-splitting photosystem NADPH-producing photosystem ATP mill Two types of photosystems cooperate in the light reactions
  • 31. Primary electron acceptor Primary electron acceptor Photons PHOTOSYSTEM I PHOTOSYSTEM II Energy for synthesis of by chemiosmosis Noncyclic Photophosphorylation Photosystem II regains electrons by splitting water, leaving O2 gas as a by-product
  • 32. The O2 liberated by photosynthesis is made from the oxygen in water (H+ and e-) Plants produce O2 gas by splitting H2O
  • 33. 2 H + 1/2 Water-splitting photosystem Reaction- center chlorophyll Light Primary electron acceptor Energy to make Primary electron acceptor Primary electron acceptor NADPH-producing photosystem Light NADP 1 2 3 How the Light Reactions Generate ATP and NADPH
  • 34. Two connected photosystems collect photons of light and transfer the energy to chlorophyll electrons The excited electrons are passed from the primary electron acceptor to electron transport chains Their energy ends up in ATP and NADPH In the light reactions, electron transport chains generate ATP, NADPH, & O2
  • 35. The electron transport chains are arranged with the photosystems in the thylakoid membranes and pump H+ through that membrane The flow of H+ back through the membrane is controlled by ATP synthase to make ATP In the stroma, the H+ ions combine with NADP+ to form NADPH Chemiosmosis powers ATP synthesis in the light reactions
  • 36. The production of ATP by chemiosmosis in photosynthesis Thylakoid compartmen t (high H+) Thylakoid membrane Stroma (low H+) Light Antenna molecules Light ELECTRON TRANSPORT CHAIN PHOTOSYSTEM II PHOTOSYSTEM I ATP SYNTHASE
  • 37. Review: Photosynthesis uses light energy to make food molecules Light Chloroplast Photosystem II Electron transport chains Photosystem I CALVIN CYCLE Stroma LIGHT REACTIONS CALVIN CYCLE Cellular respiration Cellulose Starch Other organic compounds A summary of the chemical processes of photosynthe sis
  • 38. Dark reaction (Light-independent Reaction) 6CO2 + 12H2O + light energy C6H12O6 + 6O2 + 6H2O Dark reaction: Calvin cycle regenerative anabolic CO2 in, sugar out during daylight CO2 NADP+ ADP Pi + RuBP 3-Phosphoglycerate Calvin Cycle G3P ATP NADPH Starch (storage) Sucrose (export) Chloroplast Light H2O O2
  • 39. Carbon fixation 3 stages of Calvin- cycle: #1 carbon fixation CO2 link to 5-C 5-C: ribulose bisphosphate (RuBP) - enzyme: Rubisco abundant 6-C unstable split 2(3-C)
  • 40. Reduction #2 reduction reduced 3-C: G3P 3-C reduced e- from NADPH 3 stages of Calvin- cycle:
  • 41. Regeneration of C-acceptor multiple steps uses ATP every 3 cycles: 1 G3P made 3 RuBP regenerated #3 regenerate C- acceptor still 5 G3P 3 RuBP C3 plants CO2 fixed into 3-C 3 stages of Calvin- cycle: