Chapter 10: Photosynthesis

Question 1

What are the 3 phases of photosynthesis?

Answer 1

1. Carbon Fixation
2. Reduction
3. Regeneration of CO2 acceptor (RuBP)

Question 2

Where does the light reaction occur?

Answer 2

The Thylakoid membrane

Question 3

What’s the final electron acceptor?

Answer 3

NADP+

Question 4

What goes into the Calvin Cycle (Dark Reaction)?

Answer 4

3 molecules of CO2, 6 NADPHs, and 9 ATPs

Question 5

Carbons enters the cycle as CO2 and leaves as:

Answer 5

a 3 carbon sugar: G3P

Question 6

How many ATP and NADPH do we need to make 1 G3P?

Answer 6

18 ATP and 12 NADPH

Question 7

Where does the Calvin Cycle occur?

Answer 7

Stroma

Question 8

Where does the Light Reaction occur?

Answer 8

Thylakoids

Question 9

ATP and NADPH are used to synthesize organic molecules. What is this cycle called?

Answer 9

Calvin Cycle

Question 10

Is the Calvin Cycle catabolic or anabolic?

Answer 10

Anabolic: building organic molecules from smaller components requiring energy to do so

Question 11

What does Rubisco do?

Answer 11

Catches CO2 from the atmosphere and attaches it to a sugar called ribulose biphosphate

Question 12

What are the 3 phases of photosynthesis?

Answer 12

1. Carbon Fixation
2. Reduction
3. Regeneration of CO2 acceptor (RuBP)

Question 13

Generation of proton gradients across membranes occurs during

Answer 13

both photosynthesis and respiration

Question 14

In a plant leaf, the reactions that produce NADH occur in

Answer 14

neither the light reactions nor the Calvin cycle.

Question 15

Reactions that require CO2 take place in

Answer 15

the Calvin cycle alone.

Question 16

Figure 10.1 shows the absorption spectrum for chlorophyll a and the action spectrum for photosynthesis. Why are they different?

Answer 16

Other pigments absorb light in addition to chlorophyll a.

Question 17

Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes?

Answer 17

the synthesis of ATP

Question 18

When oxygen is released as a result of photosynthesis, it is a direct by-product of

Answer 18

splitting water molecules

Question 19

What best describes the relationship between photosynthesis and respiration?

Answer 19

Photosynthesis stores energy in complex organic molecules; respiration releases energy from complex organic molecules

Question 20

The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during

Answer 20

neither photosynthesis nor respiration.

Question 21

What is the relationship between the wavelength of light and the quantity of energy per photon?

Answer 21

They are inversely related

Question 22

How many carbons are in ribulose

Answer 22

5

Question 23

Used to generate ATP molecules during photosynthesis

Answer 23

ATP synthase

Question 24

Pigments that can absorb light energy in photosynthetic organisms

Answer 24

Chlorophyll

Question 25

The difference in the number of hydrogen ions in the thylakoid lumen as compared to the stroma

Answer 25

1000 fold

Question 26

The only type of chlorophyll that participate DIRECTLY in the light reaction

Answer 26

Chlorophyll A

Question 27

An organism that cannot produce its own chemical energy

Answer 27

heterotroph

Question 28

Electron flow that occurs between photosystem II and I

Answer 28

Non-cyclic

Question 29

The color of light energy that is least useful in photosynthesis

Answer 29

Green

Question 30

Sacs within the stroma that contain chlorophyll and are the specific sites of the **light reaction** stage of photosynthesis

Answer 30

Thylakoids

Question 31

The number of NADPH required to produce one 3-carbon sugar in the dark reaction

Answer 31

6

Question 32

The by-product of the first step of the light reaction of photosystem II. Produced by *splitting water molecules*

Answer 32

Oxygen

Question 33

Split in the first step of the light reaction of photosystem II to replenish the electron lost from p680

Answer 33

water

Question 34

The chlorophyll molecule in the center of photosystem II absorbs light energy at 700nM

Answer 34

p700

Question 35

Organelles found in photosynthesis organisms that are the sites of photosynthesis

Answer 35

Chloroplasts

Question 36

**Dark reaction** in photosynthesis that converts CO2 into three-carbon sugars using ATP and NADPH generated in the light reaction

Answer 36

Calvin Cycle

Question 37

The order (from lowest energy to highest energy) of light in the visible light spectrum

Answer 37

ROYGBIV

Question 38

Electron flow that occurs **only** in **photosystem I**. Used to generate additional ATP needed for the Calvin Cycle.

Answer 38

Cyclic electron flow

Question 39

The complex of accessory pigments that transfers light energy to a central chlorophyll pigment

Answer 39

Antenna

Question 40

The number of ATPs required to produce one 3-carbon sugar in the dark reaction

Answer 40

9

Question 41

What event occurs in the light reactions of photosynthesis?

Answer 41

NADP is produced

Question 42

In a plant cell, where are the ATP synthase complexes located?

Answer 42

the Thylakoid membrane and inner mitochondrial membrane

Question 43

Reactions that require CO₂ take place in

Answer 43

The Calvin cycle alone

Question 44

What is the primary function of the Calvin cycle?

Answer 44

synthesize simple sugars from carbon dioxide

Question 45

Which of the following does *not* occur during the Calvin cycle?

Answer 45

release of oxygen

Question 46

The light reactions of photosynthesis supply the Calvin cycle with

Answer 46

ATP and NADPH

Question 47

In the thylakoid membranes, what is the main role of the antenna pigment molecules?

Answer 47

harvest photons and transfer light energy to the reaction-center chlorophyll

Question 48

Reduction of oxygen to form water occurs during

Answer 48

respiration only

Question 49

Which process is most directly driven by light energy?

Answer 49

removal of electrons from chlorophyll molecules

Question 50

In mitochondria, chemiosmosis translocates protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis translocates protons from

Answer 50

the stroma to the thylakoid space.

Question 51

The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytosol of a particular plant cell. Which, if any, relationship would you expect to find?

Answer 51

The pH within the thylakoid is less than that of the stroma.