Chapter-9 Flashcards
Photosynthesis
Convert light energy into stored chemical energy of organic molecules
What happens when a molecule absorbs a photon of light energy?
Electrons become energized
Electron shifts from a lower energy atomic orbital to a high energy orbital
Wave length
Distance from one wave peak to the next
Photons
Light is composed of small particles,or packets of energy
Ground state
Condition in which all its electrons are in their normal lowest energy levels
Fluorescence
An emission of light of a longer wave length than the absorbed light
Chloroplasts
Lie manly inside the leaf in the cells of mesophyll
Mesophyll
A layer that includes many air spaces and a very high concentration of water vapor
How many chloroplasts in a mesophyll cell
20-100
Stroma
a fluid filled region which contains most of the enzymes required to produce carbohydrate molecules
Thylakoids
Flat disc like sacs
Thylakoid lumen
Fluid filled interior space
Grana
Stacks of thylakoid sacs
Chlorophyll
The main pigment of Photosynthesis
Absorbs light primarily in the blue and red regions of the visible spectrum
Chlorophyll a
The pigment that indicates the light dependent reactions
Chlorophyll b
An accessory pigment
Carotenoids
Accessory photosynthetic pigments that are yellow and orange
Absorption spectrum
Plot of its absorption spectra for chlorophylls a and b
Action spectrum
A graph of of the relative effectiveness of different wavelengths of light
Light dependent reactions
Light energy converted to chemical energy.
Associated with thylakoids
Adenosine diphosphate forms adenosine triphosphate how
Energy of energized electrons used to phosphate
In addition NADP+ becomes reduced forming NADP1
Carbon fixation
Energy is transferred to chemical bonds in carbohydrates which can be produced in large quantities and stored for future use. Takes place in the stroma
Photosystem 1 and 2
1- pair of chlorophyll a molecules with an absorption peak at 700nm referred to as p700
2- same but peak at 680nm referred to as P680
Noncyclic electron transport
Events associated with photosystem 1
Electron transport chain
Energized electron passed along from 1 electron acceptor to another
Photolysis
Light splitting of water
ATP synthase
?
Chemiosmosis
Diffusion down a proton gradient
Calvin cycle
Carbon fixation through a sequence of 13 reactions
Ribulose bisphosphate
Reaction of CO2 with a phosphorylated five carbon compound
Rubisco
Reaction enzyme
Phosphoglycerate
?
C3 plants
Plants that initially fix carbon
C3 pathway
Another name for Calvin cycle
G3P
?
Photorespiration
1 occurs in the presence of light
2 requires oxygen
3 produces CO2 and H2O
Does not produce ATP
C4 plants
Fix CO2 into four carbon compound.
Oxaloacetate
four carbon compound.
CAM plants
Fix carbon at night
C4 pathway
CO2 is fixed through the formation of oxaloacetate
PEP Carboxylase
Catalysts the reaction by which CO2 reacts with the three carbon compound.
CAM pathway
Special carbon fixation pathway
Autotrophs
Chemical energy that can’t be stockpiled and unstable
Chemoheterotrophs and heterotrophs
Animals, fungi, most prokaryotes
Photoheterotrophs
Able to use light energy but unable to carry out carbon fixation.
Chemoautotrophs
Obtain their energy from oxidation of reduced inorganic molecules
