MB-Photosythesis and Cellular Respiration

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 In the light reactions, the energy of sunlight is used to oxidize water (the electron donor) to O2 and pass these electrons to NADP+, producing NADPH. Some light energy is used to convert ADP to ATP. The NADPH and ATP produced are subsequently used to power the sugar-producing Calvin cycle.

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 In the Calvin cycle, the energy outputs from the light reactions (ATP and NADPH) are used to power the conversion of CO2 into the sugar G3P. As ATP and NADPH are used, they produce ADP and NADP+, respectively, which are returned to the light reactions so that more ATP and NADPH can be formed.

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. In the light reactions, light energy is used to remove electrons from (oxidize) water, producing O2 gas. These electrons are ultimately used to reduce NADP+ to NADPH. In the Calvin cycle, NADPH is oxidized back to NADP+ (which returns to the light reactions). The electrons released by the oxidation of NADPH are used to reduce three molecules of CO2 to sugar (G3P), which then exits the Calvin cycle.

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- the dense fluid surrounded between the inner envelope membrane and the thylakoid membranes b) thylakoid membrane- the third membrane system; surrounds the thylakoid; chrorophyll resides in the thylakoid membrane c)cytosol- the fluid portion of cytoplasm surrounding (outside) the chloroplast d) location of Calvin Cycle- the calvin cycle occurs in the stroma e) thylakoid space- the space within the thylakoid sacs f)location of light reactions- the light reactions occur in the thylakoids of the chloroplast g) envelope membranes- the inner and outer membranes of the chloroplast The chloroplast is enclosed by a pair of envelope membranes (inner and outer) that separate the interior of the chloroplast from the surrounding cytosol of the cell. Inside the chloroplast, the chlorophyll-containing thylakoid membranes are the site of the light reactions. Between the inner envelope membrane and the thylakoid membranes is the aqueous stroma, which is the location of the reactions of the Calvin cycle. Inside the thylakoid membranes is the thylakoid space, where protons accumulate during ATP synthesis in the light reactions.

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) CHLOROPLAST d) OXYGEN & SUGAR e) CHLOROPHYLL f) CARBON DIOXIDE & ATP g) CELLULAR RESPIRATION h) MITOCHONDRIA SUNLIGHT provides energy for PHOTOSYNTHESIS PHOTOSYNTHESIS occurs in CHLOROPLASTS CHLOROPLAST contains the pigment CHLOROPHYLL PHOTOSYNTHESIS produces OXYGEN & SUGAR OXYGEN & SUGAR are inputs for CELLULAR RESPIRATION CELLULAR RESPIRATION produces CARBON DIOXIDE & ATP CARBON DIOXIDE provides carbon for PHOTOSYNTHESIS CELLULAR RESPIRATION occurs in MITOCHONDRIA A mutually dependent relationship exists between chloroplasts and mitochondria in the plant cell. Photosynthesis, which occurs in chloroplasts, generates the sugars and oxygen gas that are used in mitochondria for cellular respiration. Cellular respiration generates carbon dioxide, which in turn is used as a carbon source for the synthesis of sugars during photosynthesis. Cellular respiration also generates ATP and water, which are used in various chemical reactions in the plant cell.

Even though plants cells photosynthesize, they still use their mitochondria for oxidation of pyruvate. This will occur in _____.

photosynthesizing cells in the light and in other tissues in the dark

all cells all the time

cells that are storing glucose only

photosynthetic cells in the light, while photosynthesis occurs concurrently

All cells all the time