Photosynthesis

• • Heterotrophs
  • aka: consumers
  • animals
  • fungi
  • most bacteria
  • Autotrophs 
  • aka: producers
  • plants
  • seaweed & algae
  • photosyntheticbacteria
  • chemosynthetic organisms
• Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy.
• The equation for photosynthesis is: Carbon dioxide + water → glucose + oxygen
• Photosynthesis is a process that plants use to make their own food, producing oxygen as a by-product.
• Some protists and bacteria can also perform photosynthesis.
• Photosynthesis involves a balanced overall equation similar to aerobic cellular respiration.
• Both plants and animals need glucose for cellular respiration, but plants don't have to be in search of glucose because they make it.
• Plants have adaptations to carry out photosynthesis in a variety of environments, including capturing light.
• Plants can use light capturing molecules called pigments, with chlorophyll being a common pigment used to capture light.
• Visible light has different wavelengths and those different wavelengths of light have different colors.
• Chlorophyll does a great job at absorbing red and blue light, but not so much green light.
• Chlorophyll reflects green light, which is why many plants appear green to our eyes.
• There are pigments besides chlorophyll that work with different wavelengths of light, explaining why green is not the only color you see in plants.
• Chlorophyll is a pigment that can be found in the chloroplasts of plant cells.
• The two major reactions that occur in the chloroplast, together, make up photosynthesis: the light dependent reactions and the light independent reactions, also known as the Calvin Cycle or the dark reaction.
• Little compartments in the chloroplasts that contain pigment are called thylakoids.
• Cacti have a potential problem of living in a hot desert, and so if they open their stomata during the hot day to get their carbon dioxide, they can easily lose more water than would be ideal.
• Cacti and some other plants can do something called CAM photosynthesis, where they can open their stomata at night and capture carbon dioxide, chemically storing it, and then use this carbon dioxide the next day when the sun is shining and have their stomata closed, allowing them to avoid having to open their stomata in the heat of the day.
• The Calvin Cycle, while not directly capturing light, doesn’t require darkness either and still happens in the chloroplast.
• Plants have the ability to open and close their stomata.
• In the light dependent reactions, light is captured and water (a reactant in the photosynthesis equation) is “split,” resulting in electrons, protons, and oxygen.
• The ATP that had come from the light dependent reactions acts as an energy currency for the Calvin Cycle.
• The Calvin Cycle happens in the stroma, which is a fluid outside of the thylakoids.
• The NADPH that had come from the light dependent reactions supplies reducing power, helping add high energy electrons to this process.
• A collective stack of thylakoids is referred to as a granum, and multiple stacks are referred to as grana.
• In a complex series of pathways, the fixed carbon dioxide, ATP, and NADPH are used to make a product that can be converted into glucose.
• The light dependent reactions also produce ATP and NADPH, which are needed for the light independent reactions, also known as the Calvin Cycle or Dark Reaction.
• Plants have some amazing adaptations that help them perform photosynthesis efficiently in different environments.
• The carbon dioxide gas enters the stomata and is fixed by an enzyme, changing the inorganic carbon dioxide to a more usable organic form.
• In the Calvin Cycle, carbon dioxide enters through pores, often found on the bottom of leaves, called stomata.
• Chloroplasts are found within plant cells and contain chlorophyll, which absorbs sunlight to produce sugar.
• Light-dependent reactions occur in the thylakoid membranes of chloroplasts and involve splitting water molecules to release electrons that generate ATP and NADPH.
• What does ATP stand for?

  Adenosine Triphosphate
• What is ATP made of?

  Adenine [Nitrogenous base], 5 carbon sugar ribose, and 3 bonded phosphate groups.
• What are Organic Molecules?

  Molecules containing carbon atoms bonded to hydrogen atoms.
• What is the role of ATP?

  Active transport across cell membrane, protein synthesis, muscle contraction.