Almost all plants are photosynthetic autotrophs, as are some bacteria and protists
Name some common producers › Plants, algae, some protists, cyanobacteria Define photoautotroph...
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Transcript of Name some common producers › Plants, algae, some protists, cyanobacteria Define photoautotroph...
Autotrophs
Name some common producers› Plants, algae, some protists, cyanobacteria
Define photoautotroph› An organism that uses light energy to
produce food Define chemoautotroph
› An organism that uses chemical energy to produce food
Fig. 10-2
(a) Plants
(c) Unicellular protist10 µm
1.5 µm
40 µm(d) Cyanobacteria
(e) Purple sulfur bacteria
(b) Multicellular alga
Location of photosynthesis
State the organelle of photosynthesis› Chloroplast
Where are chloroplasts concentrated in plants?› The green tissue on the interior of the leaf› Mesolphyll
Gas Exchange
Explain how gases are exchanged between the plant and the environment.› Stoma are openings in the epidermis of
leaves› Guard cells surround the stoma and they
regulate the opening & closing of the stoma
› When open, CO2 can enter while O2 and H2O can exit
Fig. 10-3b
1 µm
ThylakoidSpace (lumen)
Chloroplast
GranumIntermembranespace
Innermembrane
Outermembrane
Stroma
Thylakoid
Structure of the
chloroplast
Thylakoid is site of
light reactions
Stroma is site of Calvin Cycle
Plants produce O2 by splitting H2O
1950’s – scientists used heavy isotope of oxygen (18O) to follow oxygen through photosynthesis.
Tagged oxygen of CO2 and found no tagged O2 given off
Tagged O2 of H2O and found tagged O2 given off
Photosynthesis is a Redox Reaction
Equation› 6CO2 + 6H2O Light C6H12O6 + 6O2
Redox reaction of photosynthesis› Oxidized:
H2O to O2
› Reduced: CO2 to C6H12O6
Overview of Photosynthesis
Photosynthesis consists of the light reactions (photo – absorbs light energy) and the Calvin cycle (synthesis – makes sugar)
2 s
tag
es o
f p
hoto
syn
thesis
Light R
eactio
ns
Calv
in C
ycle
Takes place in the thylakoids Split H2O Release O2
Reduce NADP+ to NADPH Produce ATP via photophosphorylation
Takes place in the stroma Forms sugar using
› CO2 from atmosphere
› ATP and NADPH from light reactions Starts with carbon fixation