photosythesis Flashcards
As we drill down, which cells in the plant, and then what organelles, and then what structures within that organelle, do we find the photosynthetic machinery
Incide a plant cell are chlorolplast. Light reactions occurring the thylakoid of chloroplast
What types of electromagnetic radiation are responsible for providing the energy for photosynthesis
what general wavelengths or colors (if visible) are they found?
Visible light ( 380 nm-750nm)
What are the main types of pigments that absorb the radiation, and in what two broad groups of wavelengths?
Mainly absorbs blue/indig (400-500) and orange/red (600-700)
The Chlorophyll molecule itself has features in common with a few other molecules that we looked at. What are some common features and what are some slight variations?
4 nitrogen’s stabilizing center ion
Hemoglobin has Fe and Chlorophyll has Mg
Florescence
the electron can return to the ground state with loss of light and heat
Photon hits ion, molecules gets excitedand movies to a higher energy state. Energy is released in the form of florescent light and a little heat, photon that comes in is in higher energy. light/heat is lower in energy.
Resonance
energy in electron is transferred to nearby pigments
When photon stickers, instead of releasing energy to other Chlorophyll molecules, it will pass down energy down to other Chlorophyll molecules until it reaches the reaction center
reduction/Oxidation:
electron is transferred to a new compound. The reaction center can lose an electron to an electron transport chain
Photon hots the reaction center (MG ion)and go to higher energy state. Electron acceptor grabs high energy electron (reduced) and Chlorophyll molecule will lose the electron (oxidized)
light reaction
PS2 - Light photon hits molecule, gets excited, and starts to hand down energy until it reaches the reaction center. Primary electron acceptor steals energy from ion. (redox/oxidation) and will leave system to a Etc where it will create proton pump to make ATP
Electrons move down etc releasing stored energy as it moves. Creates a hydrogen ion gradient
Simotaneously @ PS1, light hit molecule, gets excited, energy reaches reaction center, accepted by different electron acceptor, and goes down another ETC. Instead of making ATP, it will reduce NAD to NADPH
What are the products of the light reactions
ATP, NADPH, and O2.
How many electron transport systems are there in the Light Reaction
2 located along thylakoid membrane
What conditions could lead a plant to having too much light energy
high light, low temp
How can they turn this “problem” into a benefit?
Why do plant cells not want to have an excess of NADPH
calvin cycle will be sloed down and NADPH will build up linear elctron flow and can damage cells
Where in the chloroplast do the Calvin Cycle reactions take place
Stroma
What are the three main parts of the Calvin cycle?
CO2 Fixation (carbon fixing) - CO2 enters, and is attached to RuBP. result is unstable enzyme that is split into two three carbon molecule
CO2 Reduction: uses NADH and ATP to reduce CO2. 3PG reduced to G3P
RuBp Regeneration - ATp used to reform RuBP molecules continuing reactions.
