Light Independent Reaction Flashcards
other names for light-independent reaction
calvin cycle
calvin-benson-bassham cycle
dark reaction
c3 pathway
where does the Calvin cycle take place
stroma
The light-independent reactions run on the ____
and ________ molecules generated from light-
dependent reactions.
ATP and NADPH
3 main phases of the Calvin cycle
carbon fixation, reduction, RuBP regeneration
why is phase 1 termed carbon fixation
because the process involves incorporating carbon atoms from an inorganic source into an organic molecule.
in Carbon fixation, the enzyme ____________ catalyzes the reaction between the _____________ and the five-carbon sugar _________
this results in the formation of an
unstable six-carbon molecule, which
spontaneously splits into two ___________.
RuBP Carboxylase-Oxygenase (RuBisCo); Carbon Dioxide; Ribulose 1,5-Bisphosphate (RuBP), 3-Phosphoglycerate/Phosphoglyceric Acid (3-PGA)
why is phase 2 termed as reduction
because the process involves the gain of electrons from the NADPH (reduced).
reduction phase
The enzyme _______________ catalyzes the phosphorylation of 3-PGA by ATP (which was produced in the light-dependent stage). ______________________ and ______ are the products. (However, note that two 3-PGAs are produced for every CO2 that enters the cycle, so this step utilizes two ATP per CO2 fixed.)
The enzyme__________________ catalyzes the reduction of 1,3BPGA by NADPH (which is another product of the light-dependent stage). ______________ (also called G3P, GP, TP, PGAL, GAP) is produced, and the NADPH itself is oxidized and becomes _______. Again, two NADPH are utilized per CO2 fixed.
These will return to light-dependent reactions for them to be re-energized.
phosphoglycerate kinase; 1,3-Bisphosphoglycerate; ADP
glyceraldehyde 3-phosphate dehydrogenase; glyceraldehyde 3-phosphate; NADP+
why is phase 3 termed regeneration
because the process involves regenerating RuBP.
regeneration
____ G3P molecules (total of 30 carbons), from ____ CO2 molecules that are fixed, will be regenerated to six RuBP with the help of ____ ATP (likewise, a total of 30 carbons).
(For every three CO2 molecules fixed, ____ G3P
molecule leaves the cycle as a product which contributes to the formation of _______. Since six CO2 molecules are needed in photosynthesis, the products will be doubled.)
ten; six; six
one; glucose
during the regeneration phase, 3 RuBP is produced with 5 G3Ps as a reactant. Along this process, 3 ATP is also used, thus consequently producing 3 ADP. however, 2 inorganic phosphates are only produced despite this. Why is this so?
one phosphate attaches to the Carbons to produce RuBP
chemical reaction in thylakoid
12H2O + 18ADP + 18Pi + 12NADP+ → 6O2+ 18ATP + 12NADPH
the chemical reaction in the stroma
6CO2 (sometimes w/ H2O) + 18ATP + 12NADPH → C6H12O6 + 18ADP +18Pi + 12NADP+
overall photosynthetic reaction
6CO2 + 12H2O + 18ATP + 12NADPH → C6H12O6 + 6O2 + 18ADP +18Pi + 12NADP+
how much NADPH to produce 1 glucose
12
