2. PHOTOSYNTHESIS The conversion of light energy to chemical energy Stored in glucose or other organic compounds Occurs in plants, algae, and other prokaryotes
3. PHOTOSYNTHESIS Photosynthesis involves the conversion of light energy into chemical energy. The process uses light energy and simple inorganic substances such as CO2 and H2O to produce organic compounds
4. PHOTOSYNTHESIS Light from the sun is composed of a range of wavelengths (colors) Plants are photoautotrophs, organisms that use light as a source of energy to synthesize organic substances
5. PHOTOSYNTHESIS Pigments that absorb all colors except blue appear blue because his part of the sunlight is not absorbed The blue light is reflected and can pass into our eye, to be perceived by cells in the retina A white or transparent substance does not absorb visible light Pigments that absorb all of the light appear black
6. PHOTOSYNTHESIS Photosynthesis is only able to occur in wavelengths that chlorophyll can absorb Shorter wavelengths have more energy, this leads to higher rates of photosynthesis Medium wavelengths (green) have the lowest rate of photosynthesis
7. PHOTOSYNTHESIS Chlorophyll is the main photosynthetic pigment Chlorophyll is the green pigment located within chloroplasts
8. PHOTOSYNTHESIS ATP and hydrogen are used to fix carbon dioxide to make organic molecules The conversion of carbon dioxide into solid or liquid carbon compounds is called carbon fixation
9. PHOTOSYNTHESIS The three limiting factors of photosynthesis are light intensity, temperature, and carbon dioxide concentration They can all affect the rate at which a plant goes through photosynthesis if they are below the optimal level There is only one limiting factor at a time and they change throughout the process of photosynthesis
13. PHOTOSYNTHESIS The various structures in the chloroplast are highly visible in this electron micrograph image This is where photosynthesis occurs
14. PHOTOSYNTHESIS Chloroplasts have such characteristics as A double membrane called the chloroplast envelope A complex system of internal membranes known as thylakoids Small spaces of fluid inside the thylakoids Fluid surrounding the thylakoids known as stroma
15. PHOTOSYNTHESIS Photosynthesis consists of two different parts of reactions, light- dependent and light- independent Light- dependent reactions involve the production of ATP Light- independent reactions involve the production of glucose, known as the Calvin cycle However, they are a result of the light- dependent reactions so they are indirectly dependent on light
16. PHOTOSYNTHESIS Light energy is used to produce ATP and to split water molecules (photolysis) to form oxygen and hydrogen - The light energy is absorbed by chlorophyll Light- dependent reactions produce ATP by means of photophosphorylation The light absorbed takes the form of electrons in the thylakoids
17. PHOTOSYNTHESIS The process begins in Photosystem II, it then proceeds to the electron transport carrier, and then to the ATP synthase A proton concentration gradient forms in the thylakoid membrane helping to create ATP In cell respiration, this is known as chemiosmosis
18. PHOTOSYNTHESIS Photosystem I produces NADPH which is used in the light- independent reactions The chlorophyll absorb light and raise one electron to a high energy level, called photoactivation The electron is connected to the electron chain from Photosystem II and used to reduce NADP+ Cyclic photophosphorylation
20. PHOTOSYNTHESIS Carbon fixation and carbohydrate synthesis are light- independent reactions, these are known as the Calvin cycle Carbon fixation produces glycerate- 3- phosphate, a three- carbon compound The carbon dioxide mixes with ribulosebiphosphate, a 5- carbon compound to create glycerate- 3- phosphate
21. PHOTOSYNTHESIS For a carbohydrate to be produced, hydrogen has to be added to the glycerate- 3- compound, ATP and NADPH are needed for this to occur The result of this reaction is a three- carbon sugar called triose phosphate The triose phosphate is used to regenerate RuBP This cycle is called the Calvin cycle
