8/14/2019 Amanda's Handout Week 2

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8/14/2019 Amanda's Handout Week 2

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In the carbon-fixation reactions, which occur___________of the chloroplast, sugars are synthesized from carbondioxide and the hydrogen carried by NADPH. This processis powered by the ______ and _______ produced in theenergy-transduction reactions. The most important enzymeof the light-independent reactions is ________________.

To fix one molecule of CO2, a net of ____ molecules of ATPand ____ molecules of NADPH are required.

RuBisCO : ribulose-1,5-bisphosphate carboxylase/oxygenase

Carbon fixation by RUBISCO can be enhanced by increasing the ________________

concentration in the compartment containing the enzyme (chloroplast stroma). Someplants have evolved methods of maximizing the efficiency of carbon fixation.

C4 Plants:

C4 plants have maximized their carbonfixation efficiency by making structuralchanges in their leaf anatomy so thatRUBISCO is sequestered where the CO2

level is high (and O2 low). There are twoimportant cell types found in C4 plants:

______________and ____________cells.The arrangement of the cells is known as

______________________. Through thisarrangement, photorespiration is minimizedand CO2 fixation is maximized.

CAM Plants:

Instead of segregating the C4 and C3 pathways in different parts of the leaf, these types ofplants use a________________. At night, CAM plants take in CO2 through_______________.The CO2 joins with PEP to form ________________. This is converted to malic acid, whichaccumulates in the_____________of the cells. In the day, the stomata close to____________and the malic acid leaves the vacuole and is broken down to release CO2. The CO2 is taken upand used in the Calvin cycle.

8/14/2019 Amanda's Handout Week 2

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