Mastering Biology Chapter 10

Part B - Energetics of electron transport This diagram shows the basic pattern of electron transport through the four major protein complexes in the thylakoid membrane of a chloroplast.

1. no energy input required 2. energy input required 3. no energy input required 4. energy input required 5. no energy input required

Part B In C4 and CAM plants carbon dioxide is fixed in the _____ of mesophyll cells. thylakoids grana cytoplasm stomata stroma

cytoplasm

Part C C4 plants differ from C3 and CAM plants in that C4 plants _____. use PEP carboxylase to fix carbon dioxide use malic acid to transfer carbon dioxide to the Calvin cycle are better adapted to wet conditions open their stomata only at night transfer fixed carbon dioxide to cells in which the Calvin cycle occur

transfer fixed carbon dioxide to cells in which the Calvin cycle occurs

Part A In C3 plants the conservation of water promotes _____. the light reactions the opening of stomata a shift to C4 photosynthesis photorespiration photosynthesis

photorespiration

Part B - Inputs and outputs of the Calvin cycle From the following choices, identify those that are the inputs and outputs of the Calvin cycle. Drag each item to the appropriate bin. If the item is not an input to or an output from the Calvin cycle, drag it to the "not input or output" bin.

- input: ATP, NADPH, CO2 - output: ADP, NADP+, G3P - not input or output: light, glucose, O2

Part A - Inputs and outputs of the light reactions From the following choices, identify those that are the inputs and outputs of the light reactions. (Recall that inputs to chemical reactions are modified over the course of the reaction as they are converted into products. In other words, if something is required for a reaction to occur, and it does not remain in its original form when the reaction is complete, it is an input.) Drag each item to the appropriate bin. If the item is not an input to or an output from the light reactions, drag it to the "not input or output" bin.

- input: light, water, NADP+, ADP - output: O2, ATP, NADPH - not input or output: glucose, CO2,G3P

Part A - Functions of the photosystems The light reactions require the cooperation of two photosystems to power linear electron flow from water to NADP+. Drag each item into the appropriate bin depending on whether the process is associated with Photosystem II (PS II) only, Photosystem I (PS I) only, or both PS II and PS I. Note that "electron transport chain" here refers to the electron transport chain between the two photosystems, not the one that functions after PS I.

-Photosystem II oxidation of water reduction of electron transport chain between the two photosystems - Photosystem I reduction of NADP+ oxidation of electron transport chain between the two photosystems - Both light absorption reduction of primary electron acceptor

Part C - Do the light reactions of photosynthesis depend on the Calvin cycle?

The rate of O2 production would decrease because the rate of ADP and NADP+ production by the Calvin cycle would decrease.

Part A - Following carbon atoms around the Calvin cycle The net reaction of the Calvin cycle is the conversion of CO2 into the three-carbon sugar G3P. Along the way, reactions rearrange carbon atoms among intermediate compounds and use the ATP and NADPH produced by the light reactions. In this exercise, you will track carbon atoms through the Calvin cycle as required for the net production of one molecule of G3P. For each intermediate compound in the Calvin cycle, identify the number of molecules of that intermediate and the total number of carbon atoms contained in those molecules. As an example, the output G3P is labeled for you: 1 molecule with a total of 3 carbon atoms. Labels may be used once, more than once, or not at all.

a. 3 molecules 3 carbons b. 6 molecules 18 carbons c. 6 molecules 18 carbons d. 5 molecules 15 carbons e. 3 molecules 15 carbons f. 3 molecules 15 carbons

Part B - Quantifying the inputs of ATP and NADPH and output of Pi The Calvin cycle depends on inputs of chemical energy (ATP) and reductant (NADPH) from the light reactions to power the conversion of CO2 into G3P. In this exercise, consider the net conversion of 3 molecules of CO2 into 1 molecule of G3P. Drag the labels to the appropriate targets to indicate the numbers of molecules of ATP/ADP, NADPH/NADP+, and Pi (inorganic phosphate groups) that are input to or output from the Calvin cycle. Labels can be used once, more than once, or not at all.

a. 6 ATP 6 ADP b. 6 NADPH 6 NADP+ c. 6pi d. 2pi e. 3 ADP 3 ATP

Part A - Photosynthesis and respiration in plants Drag the labels from the left to their correct locations in the concept map on the right. Not all labels will be used.

a. sunlight b. photosynthesis c. chloroplasts d. sugar e. chlorophyll f. carbon dioxide g. cellular respiration h. mitochondria

Part C - Proton gradient formation and ATP synthesis

top left pink: empty bottom left: site of H+ release top right pink: site of ATP synthesis left blue: H+ pumped across membrane middle blue: empty right blue: H+ diffuses across membrane

Part C - Redox reactions of photosynthesis In photosynthesis, a redox compound that is produced in the light reactions is required to drive other redox reactions in the Calvin cycle, as shown in this figure along with other components of photosynthesis. Drag the terms to the appropriate blanks to complete the following sentences summarizing the redox reactions of photosynthesis. Terms may be used once, more than once, or not at all

1. In the light reactions, light energy is used to oxidize H2O to O2. 2. The electrons derived from this oxidation reaction in the light reactions are used to reduce NADP+ to NADPH. 3. The Calvin cycle oxidizes the light-reactions product NADPH to NADP+. 4. The electrons derived from this oxidation reaction in the Calvin cycle are used to reduce CO2 to G3P.

Part D - Chloroplast structure and function In eukaryotes, all the reactions of photosynthesis occur in various membranes and compartments of the chloroplast. Identify the membranes or compartments of the chloroplast by dragging the blue labels to the blue targets. Then, identify where the light reactions and Calvin cycle occur by dragging the pink labels to the pink targets. Note that only blue labels should be placed in blue targets, and only pink labels should be placed in pink targets.

a) stroma b) thylakoid membrane c)cytosol d) location of Calvin Cycle e) thylakoid space f)location of light reactions g) envelope membranes