Exam 2 (7)- Photosynthesis Flashcards
What kind of reactions are REDOX reactions?
coupled - they happen together
What happens during a REDOX reaction?
electrons are being passed from one molecule to another
What does it mean to be oxidized?
- loses electron
- loses energy
- often a H+
What does it mean to be reduced?
- gains electron
- gains energy
- often gains a H+
NAD
-coenzymes
nitric acid - important in cellular respiration
What is an Oxidation reaction good for?
breaking large molecules into their individual parts
FAD
-conenzymes
flavin adenine dinucleotide
What is photosynthesis in pathway terms?
Main- energy acquiring pathway
What is the job of coenzymes in REDOX reactions?
able to accept electrons and energy given up in the oxidation reactions.
- temp. holders of energy –> move energy between reaction sequences
How does photosynthesis work in general?
- captures sunlight
- solar E —> chem E
- E stored in carbohydrates
Photosynthesis delta G?
G= +685 kcal/mol ( endergonic)
Oxygenic photosynthesis?
( H2O –> O2)
- more common
- common plants
- oxygen= product
Anoxygenic
(H2S–> S)
- only bacteria
- sulfer=product
- no oxygen needed or produced
Photosynthesis reaction sequence:
6CO2+12H2O + light –> C6H12O6 +6O2
What part of the photosynthesis reaction sequence is a reduction?
6CO2—-> C6H12O6
What part of the photosynthesis reaction sequence is an oxidation?
12H2O—–> 6H2O + 6O2
light Particles act like waves ( T/F)
true
what are photons
energy packets of light
What is the relationship between the length and energy of a wave?
lower wavelength = higher energy
higher wave length = lower energy
wavelength?
distance between two wave peaks
What is the visible spectrum?
Wavelengths of light that our eyes can perceive
What are the boundaries of the visible light spectrum?
380 to 740 nm
violet——> red
Where are the dangerous wavelengths on the spectrum of light?
Below the visible spectrum
- anything under 380nm is dangerous to our bodies ( reproductive organs)
Where is chlorophyll?
In the green portions of plants
- leaf of flowering plant
- mesophyll tissue
- chloroplasts
what is mesophyll tissue?
-between the upper epidermis and lower epidermis
- has chloroplasts
How do the thylakoid membranes fit into photosynthesis?
they are a unit of photosynthesis
- chlorophyll A and B are here and are excited by the sun’s energy
Where does CO2 enter/ Oxygen leave the plant?
stomata
Where does the CO2 go after it enters the leaf?
diffuses into chloroplasts in stroma, CO2 combines with H2O to form C6H12O6 Energy supplied by light
Photosynthetic pigments?
Chemicals that absorb some wavelengths of visible light more than others.
what is true about how colors are absorbed?
colors least absorbed are reflected/transmitted most
What is the action spectrum?
it looks at wavelengths of light that elicit a particular response in physiological activities
What evidence do we have that the wavelengths of light elicit photosynthesis?
The match between action spectrum and absorption spectrum
What are the two main takeaways from the Lght Reactions? ( photo)
- chlorophyll absorbs solar energy –> Chemical E
- energized electrons move down the electron transport chain
What is the main takeaway from the Callvin ( Krebs) cycle ( synthesis)
- CO2 is reduced to a carb
- reduction requires ATP and NADPH ( light reactions)
What are the two alternate electron pathways?
-noncyclic electron pathway
- cyclic electron pathway
What do both the noncylic and cyclic pathways do?
capture light energy with photosystems
- Produce ATP - photophosphorylation
What are photosystems
Collections of chlorophyll molecules that respond to energy in sunlight
- have pigment complex
- occurs in thylakoid membranes
What is a pigment complex?
- helps collect solar energy like an antenna
photophosphorylation?
Using sunlight to take a phosphate and add it to ADP to make ATP
What does the non-cyclic pathway produce that the cyclic doesn’t?
NADPH
What does NADPH do in photosynthesis?
(Organic) molecules that carry energy between light reactions and the Calvin Cycle
how does chlorophyll operate what is called?
resonance energy transfer–a bunch of redox reaction
what is the reaction center?
where it responds most strongly to wavelengths of light and energy
