Download Overall Photosynthesis Reaction = 6CO2 + 6H2O → C6H12O6 + 6O2

MS Sastry
Leigh High School
Photosynthesis
Has 2 parts:
1) Light dependent—ATP, NADPH
2) Light independent—takes hydrogen protons and electrons and tags it to CO2 to
make C6H12O6
Similarities
Cell Respiration
Has 4 parts
1. Glycolysis—splits glucose into 2 pyruvate, 2 ATP (net), 2
NADH
2. Shuttle – 2 NADH (may be used to yield only 4 ATP
instead of 6ATP as it consumes some energy)
3. Krebs cycle—releases 6CO2 from glucose, 2 ATP, 6
NADH, 2 FADH2
4. ETC and oxidative phosphorylation
Differences
1. Both use electron transport chains to eventually produce ATP
1. Main action takes place in chloroplasts for photosynthesis
and mitochondria for cell respiration
2. Krebs cycle and Calvin cycle are similar in that starting material is regenerated
after molecules leave the cycles.
2. In photosynthesis, electrons come from water and end up as
glucose. In cell respiration, electrons enter as glucose and end
up as water.
3. G3P is formed in Calvin cycle and glycolysis.
3. NADH and FADH2 carry electrons in cell respiration, NADPH
carries electrons in photosynthesis
4. Both photosynthesis and cell respiration are emergent properties, neither can
create enough required products without all 3 processes (ex. Calvin cycle, Krebs
cycle…)
4. ATP synthesis is main reason for cell respiration, whereas
ATP is only a required product for photosynthesis to be able to
create glucose.
5. Both have 2 processes feeding into the main one.
5. Oxygen is exhaust of photosynthesis whereas carbon dioxide
is exhaust of cell respiration; oxygen is fuel of cell respiration
and carbon dioxide is fuel of photosynthesis. (Opposite
reactions)
6. ATP is a key molecule in each.
6. Photophosphorylation makes ATP in photosynthesis while
oxidative phosphorylation makes it in cell resp (and some from
substrate level phosphorylation)
7. Both rely heavily on movement of electrons for operation. Both use
chemiosmosis, Active transport, and phosphorylation.
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MS Sastry
Leigh High School
8. Mitochondria of cell respiration and chloroplasts of photosynthesis have distinct
similarities, for example, proton pumps pump H+ across a membrane from low to
high concentration (An endergonic process requiring energy). Protons diffuse back
across the membrane through ATP synthase driving synthesis of ATP.
9. Both organelles carry DNA, free ribosomes, 2 membranes, and used to be
prokaryotes once upon a time…
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