WVU Biology 102 Exam 2 (2/12)

• Parasitic plants

  Takes in nutrients from another plant. Because they don't have photosynthesis, they often don't have chlorophyll and aren't green. They are often white instead.
• CAM plants

  has stomata that only open at night to limit H2O loss. CO2 is stored until daytime when photosynthesis occurs. This is found in desert environments. It results in plants growing very slowly and requires lots of energy.
• C4 plants

  partially closed stomata to reduce water loss while still absorbing in CO2. This is commonly found in dry environments and requires more energy than C3 plants.
• C3 plants

  normal photosynthesis and stomata. This is commonly found in normal environments.
• stomata


  Small openings on the underside of leaves that open to allow CO2 in but, but also allows water out through evaporation. Closing these would help in dry conditions, but limits photosynthesis.
• Why plant colors change throughout the year

  Chlorophyll thrives in warmer temperatures so green reflects most in the spring and summer. However, in cooler temps accessory pigments thrives so fall colors of leaves show when the season changes. During those times carotenoid increases and chlorophyll decreases.
• Why plants are green

  the main pigment in plants, chlorophyll, absorbs blue and red and reflects green.
• G3P


  It is a modification of 3-PGA into a different smaller molecule. 2 of these put together form glucose. most of this molecule is recycled back into 3-PGA at the end of the Calvin cycle
• Regeneration (Calvin Cycle)

  step 3. the rest of G3P not used recycles back into the 3-PGA original molecule and the process repeats itself.
• Sugar formation (Calvin Cycle)


  step 2. energy from ATP and NADPH allows for modification of 3-PGA into a different smaller molecule called G3P. Once this has occurred 2 times, these add together to form glucose. (G3P has 3 carbons so 3+3= 6 carbon glucose)
• Fixation (Calvin Cycle)

  step 1. rubisco (an enzyme) add the carbon from CO2 to other molecules. This forms a large molecule called 3-phosphoglyceric acid (3-PGA).
• 3 steps of the synthesis reaction (Calvin cycle)

  Fixation, Sugar formation, and regeneration
• 4 steps of the photo reaction of photosynthesis

  1. The water splitting photosystems (PS2) strips water of electrons which are used to replace those lost when sunlight excites electrons in the thylakoid and moves them to the electron accepting molecules.

  2. The electrons that were excited in step 1 pump protons in and out of the thylakoid. This leads to the release of energy from the protons which is used to add a p-group to ADP, creating ATP (the 1st electron transport chain)

  3. Photosystem 1 (the NADPH producing system) takes electrons from inside the thylakoid and donates them.

  4. The 2nd electron transport chain occurs so that electrons are added to NADP + to create the energy carrier NADPH
• Light independent reactions

  the "synthesis" reaction. Stored energy is used to generate glucose. This does not need light to function and takes place in the stroma.
• Light dependent reaction

  the "photo" reaction. Sunlight is absorbed by chlorophyll and stored in ATP and NADPH. Light energy is captured and converted into stored chemical energy in the thylakoid which contains chlorophyll.
• 2 phases of photosynthesis

  The Light dependent "photo" reaction, and the Light independent "synthesis" reaction
• Replacement electrons

  electrons that come in to replace the ones that are being used in photosynthesis. they come from the break down of water in the water splitting photosystems (PS2) and from the 1est electron transport chain.
• Oxygen in photosynthesis


  It is produced as a byproduct of photosynthesis. Come from the breakdown of water in the water splitting photosystems (aka PS2)
• Plant biomass


  This does not come from the soil, it comes from the conversion of Carbon Dioxide into carbon based compounds.
• ATP


  the major energy source for cells that is stored until needed. It decomposes into ADP + P and has potential energy stored in the unstable bonds between phosphates. When the bonds break some energy is released. Because one phosphate group is lost, we now have ADP. ATP is the changed, high energy state. The bond can break and reform easily, thus making them a good choice for energy storage. This is a result of the negative change on the phosphate .
• Potential energy


  Energy that is stored due to position or composition. In photosynthesis Potential energy is stored in the bonds of ATP before the bonds are broken and the energy is released.
• Kinetic energy in photosythesis

  Energy of motion. Literally any moving particle or thing. It involves rapidly moving particles. This includes movement of the body, heat, and light. this from the sun is either converted into potential energy and stored in the autotrophs or it is transformed into heat energy.
• equation for photosynthesis

  6CO2 + 6H2O (sunlight)→ C6H12O6 + 6O2
• Photosynthesis


  how autotrophs use sunlight to create energy by converting water and carbon dioxide into energy.
• 3 ways that plants can obtain energy?

  Through photosynthesis, carnivory, and parasitism.
• Native Plants

  indigenous plants to a specific area with established animal relationships.They have evolved with pollinators and herbivores that are already here and are therefore typically very successful.
• Coevolution


  animals evolve alongside the plants so that they can still feed on the plant regardless of defensive chemicals. This results in the plants and herbivores being in an evolutionary battle of sorts where the plants want to defend themselves so they evolve chemicals, but the herbivore wants to eat the plant so they evolve immunity.
• how chemical defenses can be used for humans

  to make spices, medicines, and pesticides.
• Chemical defenses


  some plants produce chemicals called defensive compounds that make them toxic or taste bad to animals. Keeps the animals from eating plants due to the threat of illness or chemical deterrent, such as a bad taste or poison. They can be used as a chemical communicator to alert other plants that an herbivore is nearby. This causes the other plants to increase their defensive compounds. Sometimes these chemicals are detected by other animals. It can attract them to the plant to parasitize or predate the herbivore. This helps protect the plant yet again.
• Physical Defenses


  these are things like thorns, bark, sticky traps. Any aspect of the plant that makes it physically difficult to eat. It prevents animals from eating it due to threat of injury.
• 2 major

  types of herbivory defense

  Physical defenses and Chemical defenses
• fruit


  a ripened ovary from a flower that attracts animals to disperse seeds from inside the fleshy material. Some fruits are not fleshy and developed inside the seed pod.
• floral rewards


  This gives the animal a reason to come to the plant, offering either pollen, nectar, pleasing smells and colors, or a place to hide. This does , however, come at a steep energy cost for the plant.
• Animals (as a pollination/fertilization/dispersal strategy)

  plant lures in animals to move pollen and for doing so gives the animal a reward or trickery. This strategy increases the chance of the pollen getting to the right place. This utilizes floral reward and gives the animal a reason to visit the flower.
• Water (as a pollination/fertilization/dispersal strategy)


  this is not very common and is used by plants like Bryophytes. Sperm swims through water to get to the egg.
• Wind (as a pollination/fertilization/dispersal strategy)


  This requires a huge amount of pollen. These rely mostly on chance, so it is very ineffective.
• pollination


  The transfer of pollen from the anther of one flower to the stigma of another flower of the same species, plants have several different strategies to achieve this, namely wind, water, and animals.
• Ovary


  Contains and protects the ovules which when fertilized, the ovules develop into seeds which the is protected when it becomes a fruit. female structure
• Sepal

  modified leaves
• Style

  elongated stalk of stigma. A female structure.