Photosynthesis Flashcards
What is photosynthesis in plants?
• process by which green plants use sunlight to synthesize food from carbon dioxide and water
What are the 2 types of reactions in photosynthesis?
• light dependent reaction
• light independent reaction
Light dependent reaction vs. the independent light reaction:
Light DEPENDENT reaction:
• use light energy to power phosphorylation and the creation of ATP = phosphorylation
• takes place across the thylakoid membrane (inside of a chloroplast)
• ATP and NADPH are produced to provide energy for glucose production (Calvin cycle)
Light INDEPENDENT reaction:
• involves the synthesis of carbohydrates from carbon dioxide. Takes place in the stroma of the chloroplast (Calvin cycle)
What are the parts of photophosphorylation?
• PS II I (photo system II and I) - protein complexes that absorb light energy and transfers, the energy to electrons that then travel through the electron transport chain (ETC)
PS II:
• contains the pigment P680 and is where the oxidation of water takes place
PS 1:
• contains the pigment P700
B6 -F complex:
• enzyme that actively pumps, hydrogen ions into the thylakoid space and is powered by electron transfer
NADP Reductase:
• enzyme that reduces NADP into NADPH using ETC
What are the two types of photophosphorylation explain
Non-cyclic:
• the ETC has the electron taken up by NADP plus and H2O is oxidized to replenish missing electrons
Cyclic:
• the electron is recycled through the chain again in order to further power, the active transport of hydrogen ionsZ This helps to increase the production of ATP
• does not produce NADPH and oxygen
What are the three phases to the Kelvin cycle? Explain.
- Finding carbon dioxide:
• involves combining CO2 with RUBP to form 2 components of three phosphoglycerate
*C3 plants will use this method in order to create this stable intermediate of 3-phosphoglycerate
- Reduction:
• convert three phosphoglycerate into G3P which has a higher energy state
• endogenic reaction - form of ATP in NADPH
• ATP goes on to form ADP and NADPH is oxidized to form NADP +
*2 of the created G3P molecules move on to create glucose. The rest of the 10 G3 P molecules will go onto the third stage so they can be recycled and reused in the Kelvin cycle as RuBP
- Regenerating RuBP:
• ATP is required to reform RUBP from the smaller molecules of G3P. Kinase enzymes will be involved in these reactions
What needs to happen in order to create one glucose molecule from the Calvin cycle?
• the Calvin cycle must go 6 times
• this produces 12 G3 P molecules (3 carbon molecules)
• 2 of the 12 G3 P go onto create glucose
• 10 of the 12 G3 piece stay in the cycle to create RUBP
