MasteringBiology: Ch 10

Campbell Figure Walkthrough: How Linear Electron Flow During the Light Reactions Generates ATP and NADPH Part E Why is it correct to say that the linear electron flow of the light reactions directly captures energy in NADPH but only indirectly captures energy in ATP?

Electrons are directly transferred to NADP+ to form NADPH, but electron flow is used to generate a proton gradient for ATP synthesis. Electrons are not directly transferred to ATP.

Get Ready for This Chapter: Chapter 10 Question 3 What happens along an electron transport chain?

Electrons are passed from a reducing agent to an oxidizing agent, releasing free energy at each step.

Activity: Chemiosmosis Part B True or false? The chemiosmotic hypothesis states that the synthesis of ATP generates a proton gradient that leads to electron flow through an electron transport chain.

False

Activity: Chemiosmosis Part E True or false? The region of ATP synthase that catalyzes the production of ATP from ADP and inorganic phosphate spans the chloroplast membrane.

False

Campbell Figure Walkthrough: How Linear Electron Flow During the Light Reactions Generates ATP and NADPH Part A Which of the following is the correct order of electron flow in the light reactions of photosynthesis?

H2O → P680 chlorophyll a pair → PS II primary electron acceptor → Pq → cytochrome complex → Pc → P700 chlorophyll a pair → PS I primary electron acceptor → Fd → NADPH

Photosynthesis (2 of 3): The Light Reactions (BioFlix tutorial) Part A - Functions of the photosystems 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 (PS II) only: oxidation of water reduction of electron transport chain... Photosystem I (PS I) only: reduction of NADP+ oxidation of electron transport chain... Both PS II and PS I: light absorption reduction of primary electron acceptor

Interpreting Data: Absorption Spectra and Photosynthetic Pigments Part D Can you tell from these absorption spectra whether red light is effective in driving photosynthesis?

One cannot tell from this graph, but because chlorophyll a does absorb red light, we can predict that it would be effective in driving photosynthesis.

Activity: Chemiosmosis Part A Which term describes ATP production resulting from the capture of light energy by chlorophyll?

Photophosphorylation

Activity: Chemiosmosis Part C According to the chemiosmotic hypothesis, what provides the energy that directly drives ATP synthesis?

Proton gradient

Activity: Chemiosmosis Part D Which of the following particles can pass through the ATP synthase channel?

Protons

Activity: Light Energy and Pigments _____ has a longer wavelength than _____.

Red ... green

Photosynthesis (1 of 3): Inputs, Outputs, and Chloroplast Structure (BioFlix tutorial) Part D - Chloroplast structure and function 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.

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

Energy Flow in Plants -- Concept Map 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

Chapter 10 Pre-Test Question 3 The photosynthetic membranes are found in the _____ in plant cells.

chloroplasts

Scientific Skills Exercise: Making Scatter Plots with Regression Lines Part A - Making a graph with the data What variable did the researchers intentionally vary in the experiment, and what are the units for this variable? (This is the independent variable.)

concentration of CO2 in the air, in parts per million

Scientific Skills Exercise: Making Scatter Plots with Regression Lines Part K What is the estimated dry mass of corn and velvetleaf plants at an atmospheric CO2 concentration of 800 ppm?

corn: 84 g; velvetleaf: 50 g

Scientific Skills Exercise: Making Scatter Plots with Regression Lines Part J - Using data from the graph What is the estimated dry mass of corn and velvetleaf plants at an atmospheric CO2 concentration of 390 ppm (current levels)?

corn: 91 g; velvetleaf: 38 g

Activity: Photosynthesis in Dry Climates Part B In C4 and CAM plants carbon dioxide is fixed in the _____ of mesophyll cells.

cytoplasm

Chapter 10 Pre-Test Question 10 C4 plants occur more commonly in desert conditions because _____.

they can fix carbon at the lower CO2 concentrations that develop when the stomata are closed

Activity: Photosynthesis in Dry Climates Part C C4 plants differ from C3 and CAM plants in that C4 plants _____.

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

Chapter 10 Pre-Test Question 4 In the electromagnetic spectrum, the type of radiation that we call visible light occurs between _____.

ultraviolet radiation and infrared radiation

Activity: Overview of Photosynthesis Part C The light reactions of photosynthesis use _____ and produce _____.

water ... NADPH

Scientific Skills Exercise: Making Scatter Plots with Regression Lines Part E Which of the following graphs correctly presents the data from the experiment?

"Dry Mass (g) is y-axis and CO2 Concentration (ppm) is x-axis" "Corn plot points are above velvetleaf"

Experimental Inquiry: Which Wavelengths of Light Drive Photosynthesis? Part C - Experimental prediction: The action spectrum Which red line shows the same action spectrum corrected for the unequal number of photons emitted across the visible spectrum?

"the lines only touch at the dip in the middle of the graph"

Scientific Skills Exercise: Making Scatter Plots with Regression Lines Part F Which of the following graphs has the best-fit regression lines correctly drawn?

"the one with the lines actually going through the points"

Activity: The Light Reactions Part E Chlorophyll can be found in _____.

A and C

Activity: Chemiosmosis Part F Chloroplast membrane vesicles are equilibrated in a simple solution of pH 5‎ . The solution is then adjusted to pH 8‎ . Which of the following conclusions can be drawn from these experimental conditions?

ATP will not be produced because there is no ADP and inorganic phosphate in the solution.

Get Ready for This Chapter: Chapter 10 Question 1 Which of the following is a true statement?

Anabolic pathways build molecules, require energy, and are endergonic.

Scientific Skills Exercise: Making Scatter Plots with Regression Lines Part G - Interpreting the graph What is the relationship between increasing concentration of CO2 and the dry mass of corn?

As CO2 increases, the dry weight of corn decreases.

Scientific Skills Exercise: Making Scatter Plots with Regression Lines Part H What is the relationship between increasing concentration of CO2 and the dry mass of velvetleaf?

As CO2 increases, the dry weight of velvetleaf increases

Scientific Skills Exercise: Making Scatter Plots with Regression Lines Part I - Making a prediction Considering that velvetleaf is a weed invasive to cornfields, how would you predict increased CO2 concentration to affect interactions between the two species?

As atmospheric CO2 rises, velvetleaf weeds may grow larger and better compete with corn, reducing grain yields.

Activity: The Light Reactions Part B _____ releases energy that is used to pump hydrogen ions from the stroma into the thylakoid compartment.

B

Chapter 10 Pre-Test Question 9 The overall function of the Calvin cycle is _____.

making sugar

Chapter 10 Pre-Test Question 7 Photosynthesis is a redox reaction. This means that H2O is _____ during the light reactions and CO2 is _____ during the Calvin cycle.

oxidized...reduced

Chapter 10 Pre-Test Question 5 Which of the following is a product of the light reactions of photosynthesis?

oxygen, ATP, and NADPH

Activity: Photosynthesis in Dry Climates Part A In C3 plants the conservation of water promotes _____.

photorespiration

Photosynthesis (2 of 3): The Light Reactions (BioFlix tutorial) Part C - Proton gradient formation and ATP synthesis Drag the labels to the appropriate locations on the diagram of the thylakoid membrane.

red top left: Group 2 red bottom left: site of H+ release left blue: H+ pumped across membrane middle blue: Group 1 right blue: H+ diffuses across membrane right red: site of ATP synthesis

Chapter 10 Pre-Test Question 6 When light strikes chlorophyll molecules, they lose electrons, which are ultimately replaced by _____.

splitting water

Chapter 10 Pre-Test Question 2 The ultimate source of energy to support most life on Earth is _____.

sunlight

Campbell Figure Walkthrough: How Linear Electron Flow During the Light Reactions Generates ATP and NADPH Part C How many electrons at a time are passed between the pigment molecules in the light-harvesting complexes?

0

Photosynthesis (1 of 3): Inputs, Outputs, and Chloroplast Structure (BioFlix tutorial) Part C - Redox reactions 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. H2O, O2 2. NADP+, NADPH 3. NADPH, NADP+ 4. CO2, G3P

Photosynthesis (2 of 3): The Light Reactions (BioFlix tutorial) Part B - Energetics of electron transport For each step of photosynthetic electron flow from water to NADP+, drag the appropriate label to indicate whether or not that step requires an input of energy.

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

Scientific Skills Exercise: Making Scatter Plots with Regression Lines Part D Assuming that the y-axis tick marks will be separated by 10 (0, 10, 20, and so on), what is the largest value that should appear on the y-axis?

100

Scientific Skills Exercise: Making Scatter Plots with Regression Lines Part C Assuming that the x-axis tick marks will be separated by 200 (0, 200, 400, and so on), what is the largest value that should appear on the x-axis?

1200

Campbell Figure Walkthrough: How Linear Electron Flow During the Light Reactions Generates ATP and NADPH Part D Drag the numbers on the left to complete the sentence on the right. Numbers may be used once, more than once, or not at all.

2, 4

Experimental Inquiry: Which Wavelengths of Light Drive Photosynthesis? Part A - Experimental technique: Using bacteria to estimate rates of photosynthesis Drag the labels onto the flowchart to show the relationship between the production of photons by the sun (Engelmann's light source) and the distribution of bacteria that Engelmann observed under his microscope. Not all labels will be used.

2. Prism disperses sunlight... 3. Alga's photosynthetic pigments absorb photons at specific wavelengths. 4. Absorbed photons... 5. Alga gives off oxygen... 6. Bacteria attracted to regions of...

Interpret the Data: Which Wavelengths of Light Are Most Effective in Driving Photosynthesis? Which wavelengths of light drive the highest rates of photosynthesis? Select the two best answers.

400-450 nm 670-680 nm

Interpreting Data: Absorption Spectra and Photosynthetic Pigments Part A Approximately what wavelength of light is best absorbed by chlorophyll a, the pigment that participates directly in the light reactions?

435 nm

Interpreting Data: Absorption Spectra and Photosynthetic Pigments Part B Which wavelength of light is best absorbed by chlorophyll b?

455 nm

Activity: Overview of Photosynthesis Part A Which of these equations best summarizes photosynthesis?

6 CO2 + 6 H2O → C6H12O6 + 6 O2

Activity: The Light Reactions Part C _____ splits water into 1/2 O2, H+, and e- .

A

Activity: The Sites of Photosynthesis Part A Identify the chloroplast.

A

Activity: The Light Reactions Part D Energized electrons from ____ are used to reduce NADP+.

C

Campbell Figure Walkthrough: How Linear Electron Flow During the Light Reactions Generates ATP and NADPH Part F If the Calvin cycle slows down, what will happen to the rate of O2 production in PS II, and why?

O2 production will slow down because less NADP+ will be regenerated in the Calvin cycle.

Activity: The Sites of Photosynthesis Part C Identify a thylakoid.

D

Activity: Overview of Photosynthesis Part B Where does the Calvin cycle occur?

E

Activity: The Light Reactions Part A Which of these phosphorylates ADP to make ATP?

E

Activity: The Sites of Photosynthesis Part B Identify the stroma.

E

Chapter 10 Pre-Test Question 8 Which of the following products of the light reactions of photosynthesis is consumed during the Calvin cycle?

NADPH

Experimental Inquiry: Which Wavelengths of Light Drive Photosynthesis? Part B - Experimental results: Colors of light that drive photosynthesis What assumptions did Engelmann make in order to conclude that red and violet-blue light were more effective than green light in driving photosynthesis? Select the two that apply.

The distribution of chloroplasts within each algal cell was approximately the same The number of bacteria clustered at each wavelength (color) was approximately proportional to the amount of oxygen being produced by that portion of the alga.

Scientific Skills Exercise: Making Scatter Plots with Regression Lines Part L If atmospheric CO2 concentration increases from 390 ppm to 800 ppm, what is the estimated percentage change in dry mass for corn? For velvetleaf?

The dry mass of corn would decrease by about 8%, and the dry mass of velvetleaf would increase by about 32%.

Get Ready for This Chapter: Chapter 10 Question 2 Which of the following statements is not true of most cellular redox reactions?

The electron acceptor is reduced, acting as a reducing agent.

Campbell Figure Walkthrough: How Linear Electron Flow During the Light Reactions Generates ATP and NADPH Part B When a pigment molecule in a light-harvesting complex absorbs a photon of light, what happens to its excited-state electron?

The electron falls back to its ground state, while passing its excited-state energy to an electron in a nearby pigment molecule

Interpreting Data: Absorption Spectra and Photosynthetic Pigments Part E If only chlorophyll a were involved in the light reactions, would blue light (wavelength about 490 nm) be effective in driving photosynthesis?

The graph indicates that chlorophyll a absorbs very little blue light, so we can predict that blue light would not be effective.

Photosynthesis (3 of 3): The Calvin Cycle (BioFlix tutorial) Part C - Do the light reactions of photosynthesis depend on the Calvin cycle? Suppose that the concentration of CO2 available for the Calvin cycle decreased by 50% (because the stomata closed to conserve water). Which statement correctly describes how O2 production would be affected? (Assume that the light intensity does not change.)F

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

Interpreting Data: Absorption Spectra and Photosynthetic Pigments Part F An action spectrum plots the rate of photosynthesis at various wavelengths of visible light, and it shows that blue light with a wavelength of about 490 nm is effective in driving photosynthesis. Based on this information and the absorption spectra shown at left, what role may chlorophyll b and carotenoids play in photosynthesis?

These pigments are able to absorb more wavelengths of light (and thus more energy) than chlorophyll a alone can absorb. As part of light-harvesting complexes in photosystems, they broaden the range of light that can be used in the light reactions.

Interpreting Data: Absorption Spectra and Photosynthetic Pigments Part C You obtain the pigments called carotenoids in your diet when you eat carrots. Why do carotenoids appear yellow and orange?

They absorb blue/green light and reflect yellow and red wavelengths of light.

Chapter 10 Pre-Test Question 1 Plants are photoautotrophs. What does this mean?

They use light energy to drive the synthesis of organic molecules from inorganic materials.

Scientific Skills Exercise: Making Scatter Plots with Regression Lines Part M - Evaluating a hypothesis Do these results support the conclusion from other experiments that C3 plants have a better growth response than C4 plants under increased CO2 concentration? Why or why not?

Yes, because C3 velvetleaf had a positive growth response to increased CO2, but C4 corn had a negative growth response to it.

Photosynthesis (3 of 3): The Calvin Cycle (BioFlix tutorial) Part A - Following carbon atoms around the Calvin cycle 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

Photosynthesis (3 of 3): The Calvin Cycle (BioFlix tutorial) Part B - Quantifying the inputs of ATP and NADPH and output of Pi 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. 6 Pi d. 2 Pi e. 3 ADP 3 ATP

Scientific Skills Exercise: Making Scatter Plots with Regression Lines Part B What variable's response to the independent variable was measured by the researchers, and what are the units for this variable?

average dry mass of one plant, in grams

Photosynthesis (1 of 3): Inputs, Outputs, and Chloroplast Structure (BioFlix tutorial) Part B - 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- O2, glucose, light

Photosynthesis (1 of 3): Inputs, Outputs, and Chloroplast Structure (BioFlix tutorial) Part A - Inputs and outputs of the light reactions 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- NADPH, O2, ATP not input or output- glucose, CO2, G3P