photosynthesis

• NADPH and ATP are the product of this reaction.
• The release of hydrogen will attract inorganic phosphate to make the ADP to ATP.
• Photosynthesis is a two-phase anabolic pathway in which the Sun’s light energy is converted to chemical energy for use by the cell.
• Photosynthesis combines CO2 and H2O, producing glucose and O2.
• Photosynthetic organisms perform photosynthesis.
• Autotrophs produce their own food, such as chemoautotrophs and photoautotrophs.
• Photosynthetic autotrophs capture energy from the sun to produce their own food, such as plants, algae, and some bacteria.
• Anoxygenic photosynthesis does not produce oxygen, examples include purple bacteria, green sulfur bacteria, green non-sulfur bacteria, and heliobacteria.
• Oxygenic photosynthesis produces oxygen, examples include cyanobacteria, some groups of algae, and essentially all land plants.
• Light capturing events in photosynthesis involve chlorophyll absorbing light energy that will excite the electrons in the chloroplast, driving the production of ATP.
• Light-dependent reactions, also known as light reaction, use excited electrons to drive the production of ATP and produce hydrogen and oxygen as by-products.
• Light-independent reactions, also known as dark reaction, use ATP and NADPH to attach carbon dioxide to a 5 – carbon molecule to produce a larger organic molecule, glucose (C6H12O6).
• 6CO2 (carbon dioxide) + 6H2O (water) + light → C6H12O6 (glucose) + 6O2 (oxygen).
• Light travels as waves through a medium.
• Different types of energy have different wavelengths, such as microwaves, radio waves, x rays, gamma rays, visible light.
• The spectrum of visible light energy ranges from 350 - 790 nm.
• Different wavelengths in the visible spectrum are seen by our eyes as different colors, for example, ROY G BIV.
• White light is a combination of all the different wavelengths of visible light.
• When light strikes any object, some light is absorbed by pigments, the rest of the light is reflected off of the object.
• Pigments are molecules that absorb light, each pigment only absorbs certain wavelengths of light, the wavelengths that are not absorbed are reflected.
• Our eyes see objects by receiving the reflected light, we only see the unabsorbed light.
• Light is measured in photons, a photon is the unit of light.
• The energy in a photon is related to its wavelength, shorter wavelength = higher energy, longer wavelength = lower energy.
• When a photon hits a pigment molecule, electrons are excited, the electrons jump up to a higher energy level.
• Chloroplast, commonly found in leaves, captures light energy essential for photosynthesis.
• Thylakoids, found within the chloroplast, are flattened, sac-like membranes that are arranged in stacks called granum (the inside is called thylakoid lumen).
• Stroma are the fluid-filled space present within the chloroplast.
• Chlorophylls are pigments that absorb light, each chlorophyll only absorbs certain wavelengths of light, the wavelengths that are not absorbed are reflected.
• Hydrogen ions will accumulate in the lumen during the light-dependent reactions, and they will be re-energized when the light strikes the photosystem I (P700).
• Chlorophylls are the light-absorbing pigments found in the thylakoids of the chloroplast.
• Chlorophyll b is an aldehyde.
• Chlorophyll and accessory pigments are organized into photosystems that harvest the energy from many wavelengths of light.
• There are two photosystems, I and II.
• Photosystem I (PSI) passes electrons to NADP+ to make NADPH’s.
• Protein complexes such as ferredoxin, NADPH, and plastoquinone are involved in the light-dependent reactions.
• Protons diffuse through ATP synthase, which makes ATP that is released into the stroma.
• ATP synthase will release hydrogen ions during the light-dependent reactions.
• The Reaction Center collects energy from the antenna complex, excites electrons, and passes them to an electron acceptor.
• The Electron Transport Chain occurs between PSII and PSI and electrons are passed through an electron transport chain (ETC).
• Splitting of water is called photolysis.