Energy Autotrophs & Heterotrophs | ATP | Photosynthesis & Respiration Overview.
Introduction/Basic Info Photosynthesis. Essential for all life on earth Autotrophs Consumers...
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Transcript of Introduction/Basic Info Photosynthesis. Essential for all life on earth Autotrophs Consumers...
Introduction/Basic Info
Photosynthesis
PhotosynthesisEssential for all life on earthAutotrophs
Consumers
Photosynthesis
Glucose (only an example)Respiration
CO2
PhotosynthesisSo how do we actually see different
colors?The wavelength of the light will
determine the color of the light
PhotosynthesisWhen light waves are absorbed from
this region of the visible spectrum it can be used by a plant
Green leaves look green because they have a pigment that does not absorb green light, it reflects it
Photosynthesis
PhotosynthesisThe main light absorbing pigment in green plants is
chrorophyll—found inside the chloroplasts
Like a mitochondrion, the structure of the chlorophyll is directly related its function (common theme in bio)
Have their on DNA in a ring, ribosomes (70S), an inner and outer membranes
Only actual green structures in a plant
Photosynthesisstarch granuleRibosomes in
stroma
Stoma lamellae
PhotosynthesisChlorphyll is a green pigment
Reflects green wavelengths of light, in the middle of the VS, absorbs non-green wavelengths
Blue and red regions are absorbed the most
Absorption spectra show which wavelengths are absorbed as a function of O2 production
Photosynthesis
PhotosynthesisTwo stages of photosynthesis: light
independent and light dependent
Different sets of reactions used in each stage
Light dependent produces ATP and allows photolysis to occur (O2 is a waste product)
Light independent allows for carbon fixation
Photosynthesis—Light dependent
Chlorophyll, and other pigments, absorb light from the sun (or other source)
Energy from absorbed wavelengths produces ATP
Light also used to split water into H2 and O2 (photolysis)
Released O2 is source of aerobic respiration; ATP and H2 used by the plant
Photosynthesis—Light dependent
light
water
H+
O2
electrons
H2
Chlorophyll and other
photosynthetic pigments
Light dependent
reactions
ATP
• ATP production very similar to that of respiration w/ most energy being acquired via an electron transport chain
ATP and H2 generated from light dependent stage used to covert CO2 and H2O into organic compounds (like glucose)
This carbon fixation…turning inorganic to organic
Fixation requires energy—all comes from sun
Photosynthesis—Light independent
6CO2 + 6H2O C6H12O6 + 6O2
Photosynthesis6CO2 + 6H2O C6H12O6 + 6O2C6H12O6 + 6O2 6CO2 + 6H2O
RESPIRATION!!!!
Plants do both…photosynthesis and respiration
Respiration occurs at a slow, steady rate, regardless of light/dark = small yields of ATP. Why?
No muscle, large movement, or other energy requiring processes…less ATP needed vs animals
Photosynthesis-rates
Photosynthesis does not occur at such a steady rate
Greatly affected by intensity of light, temperature, and CO2 levels
Can be measured directly via CO2 intake and O2 production amounts IF adjusted to account for respiration
Biomass (amount of plant/size) is an indirect method of measuring rate of photosynthesis—indirect b/c a lot of other potential factors
Photosynthesis-rates
0
Day 1 Night 1 Day 2 Night 2
O2 released+ Photosynthesis
RespirationO2 taken in--
Photosynthesis-rates
Light intensity—varies inversely with the square of the distance (farther away, less intense)
Rate
of
ph
oto
syn
thesi
s
intensity
Enzymes at max rate
Photosynthesis-rates
Temperature
Rate
of
ph
oto
syn
thesi
s
Temp
Enzymes and other proteins begin to get denatured
Photosynthesis-rates
CO2 concentration
Rate
of
ph
oto
syn
thesi
s
CO2
Plateaus unless light intensity or temp. go up