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Photosynthesis/Cellular Respiration Cheat Sheet by

Photosynthesis/Cellular Respiration

Major Formulas

Cellular Respir­ation
C6H12O6 + O2 → H2O + CO2
H2O + CO2 → C6H12O6 + O2
Carry e- in the form of H+ ions. They drop e- either at the ETC to make ATP or the Calvin Cycle to help bond formation.
ATP Syntha­se:
Enzyme that synthe­sizes ATP - Uses chemio­smosis in order to in order to phosph­orylate ADP into ATP

ATP Synthase

ATP Synthase transports a proton down the gradient and uses the energy to complete the phosph­ory­lation of ADP to ATP.




2 ATP + 1 Glucose → 2 pyretic acid + 4 ATP
PFK = al­los­­teric enzyme inhibited by ATP

Kreb­bs/­Citric Acid Cycle

Subs­tr­ate Level Phosph­ory­lat­ion: ATP + pyruvate
Pyru­va­te + ­coe­nzyme A: acetyl CoA
Prod­ucts: 3 NADH, 1 ATP, 1 FADH, CO₂
Equa­tion: 2acetyl groups + 6NAD+ + 2FAD + 2ADP + 2Pi → 4CO2 + 6NADH + 6H+ + 2 FADH2 + 2ATP


Oxygen = Final e- Accept­or.
Step 1: Generating a Proton Motive Force.
Step 2: ATP Synthesis via Chemio­smosis.
Step 3: Reduction of Oxygen.
Summary: Oxidative Phosph­ory­lation.


Facu­lt­­ative Anaero­bes
Tolerate, but do not use, O₂
Obligate Anaero­bes
Cannot live in an enviro­­nment w/O₂
Alco­holic Fermen­tat­ion
Converts pyruvate into ethyl alcoho­l + CO₂ & oxidizes NADH to NAD+
Lactic Acid Fermen­tat­ion
Reduces pyruvate into lactic acid (lactate) & oxidizes NADH to NAD+


Light Dependent Stage

Key Points
In light-­dep­endent reactions, the energy from sunlight is absorbed by chloro­phyll and converted into chemical energy in the form of electron carrier molecules like ATP and NADPH.
Light energy is harnessed in Photos­ystems I and II, both of which are present in the thylakoid membranes of chloro­plasts.

Calvin Cycle / Light Indepe­ndent Stage

Key Points
Carboh­ydrate molecules are assembled from carbon dioxide using the chemical energy harvested during the light-­dep­endent reactions.


The movement of ions across a semipe­rmeable membrane, down their electr­och­emical gradient. An example of this would be the generation of adenosine tripho­sphate (ATP) by the movement of hydrogen ions (H+) across a membrane during cellular respir­ation or photos­ynt­hesis.

Photor­­es­p­i­ra­­tion, C-4, & CAM

rubisco binds with O₂ instead of CO₂; produces no ATP or sugar
C-4 Plants
Use alternate C-fixation (PEP carbox­­ylase) that ends in a 4C compound (occurs in mesophyll & bundle sheath cells)
CAM Plants
Carbon fixation to organic acids at night → light reactions release CO₂ in the day

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