Plant Physiology

1. The reaction, Fe³⁺ → Fe²⁺ is an example of:
a. oxidation b. reduction

3. The functional group that is labeled #1 is a(n):
        a. carbonyl group                         d. ketone group
        b. carboxyl group                         e. methyl group
        c. hydroxyl group

4. Which coenzyme is most likely to be involved in this reaction?
a. NADP+ b. NAD+ c. NADH + H+

Use the standard equation for photosynthesis: CO₂ + H₂O → (CH₂O)_n + O₂ to answer the next questions.

5. Photosynthesis is a redox reaction. Which of the following is oxidized during the process?
a. carbon dioxide c. water
b. carbohydrate d. oxygen

6. The electrons for the reduction reaction in photosynthesis come from:
a. carbon dioxide c. water
b. carbohydrate d. oxygen

7. The oxygen released from photosynthesis comes from:
        a. water                                 d. carbon dioxide
        b. RuBP                                  e. the Calvin Cycle
        c. glucose

8. Jean Baptista van Helmont (1577 � 1644) performed an experiment in which he placed a willow seedling in a sealed pot. He watered the plant regularly. The plant weighed five pounds at the beginning of the experiment and 169 pounds at the conclusion of the experiment five years later. The weight of the soil in the pot decreased by two ounces during the five year period. The primary source of the increased weight (mass) of the plant is from:
        a. the water he added                                     d. oxygen in the air
        b. minerals that were present in the soil        e. sugars absorbed through the roots
        c. carbon dioxide in the air

Bonus Question (3 pts): calculate the approximate weight of the plant contributed by water, minerals and carbon dioxide. Show your work.

9. The pigments that are important in photosynthesis are located in:
        a. the matrix                          d. photosystems I and II
        b. the stroma                          e. the outer membranes of the chloroplast
        c. the cytoplasm

9. During photophosphorylation, the electron transport chain moves protons into the:
        a. cytoplasm                    d. thylakoid space
        b. matrix                          e. none of the above
        c. stroma

10. Assume a thylakoid is somehow punctured so that the thylakoid space is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes?
        a. the splitting of water.
        b. the absorption of light energy by chlorophyll.
        c. the flow of electrons from photosystem II to photosystem I.
        d. the synthesis of ATP.
        e. the reduction of NADP⁺

11. The primary function of the light-dependent reactions of photosynthesis is to:
        a. produce carbon dioxide
        b. use ATP to make glucose.
        c. convert light energy to glucose.
        d. produce energy-rich ATP and NADPH.
        e. produce energy-rich glucose from carbon dioxide and water.

12. Which of the wavelengths of light is LEAST effective in photosynthesis?
a. blue b. red c. green

13. Which is formed during non-cyclic photophosphorylation but not during cyclic photophosphorylation?
        a. ATP                                    d.   NADPH
        b. carbon                                e. dioxide water
        c. glucose

14. Assume a thylakoid is somehow punctured so that the thylakoid space (lumen) is no longer separated from the stroma. This damage will have the most direct effect on which of the following processes?
        a. the splitting of water.
        b. the absorption of light energy by chlorophyll.
        c. the flow of electrons from photosystem II to photosystem I.
        d. the synthesis of ATP.
        e. the reduction of NADP+.

Leaf Structure Matching. Draw a line from the diagram to the name of the structure. Then draw a line connecting the structure name to its function.

Pigment Matching. Match each of the following with the appropriate pigment.

1		hydrophobic
2		occur in the thylakoid membranes
3		P680 and P700 are examples
4		absorbance spectrum shows one peak in the blue region (400 nm)
5		absorbance spectrum shows peaks in the red and blue spectrum
6		absorbance maximum in red region at 680 nm
7		absorbance maximum in red region at 660 nm
8		accessory pigments
9		contains chelated magnesium
10		derived from glutamate
11		blue-green color
12		yellow green color
13		phytol tail
14		porphyrin ring
15		primary photosynthetic pigment
16		similar structure to heme
17		terpenes
18		tetrapyrolle
19		yellow to orange in color
20		Identity of Pigment 2 (note: pigment 1 is bacteriochlorophyll)
21		Identity of Pigment 3
22		Identity of Pigment 4
23		Identity of Pigment 5

(diagram from Taiz & Zeiger)

Sunglass Question:
Explain why the world looks rosy (=reddish) when you look through a pair of sunglasses with red lens.

Greening Question: Identify three reasons why light is required for a plant to turn green.

1.
2.
3.

Exciting Question: Chlorophyll molecules do not remain excited for long. Identify four things that can happen to an excited molecule:

1.
2.
3.
4.

Calculation Question: Calculate the amount of energy (kJ mol^-1) in green light photons with a wavelength of 550 nm)? Hints: E = hυ and v = c/λ and h = 6.6255 x 10^-34 j sec photon^-1. Show your work.

Chloroplast Complex Matching: Match each of the following with the appropriate complex in which it occurs.

a. Photosystem II	c. Cytochrome b/f	e. Photosystem I & II	g. all of the complexes
b. Photosystem I	d. ATP synthase	f. Photosystem I, photosystem II and cytochrome b/f	h. none of the complexes

1		requires light
2		occurs in the thylakoids
3		occurs in the stroma
4		P680
5		P700
6		Coupling Factor CFo
7		phaeophytin and manganese associated
8		phylloquinone (vitamin K) and iron-sulfur proteins
9		occurs in stacked (appressed regions)
10		occurs in unstacked (un-appressed) regions
11		water oxidation occurs
12		NADP+ reduction occurs
13		gives electrons to plastoquinone (PQ)
14		receives electrons from plastoquinone (PQ)
15		gives electrons to plastocyanin (PC)
16		receives electrons fro plastocyanin (PC)
17		contains the D1 and D2 integral proteins
18		generates a proton gradient across the membrane
19		directly inhibited by DCMU
20		directly inhibited by viologen dyes (paraquat)
21		electron transport chain in the chloroplast
22		photophosphorylation
23		source of oxygen released

1		Water gives its electrons to PSII.
2		The mobile electron carrier between PSII and cytb/f is plastocyanin
3		The Z-scheme occurs in the stroma of the chloroplast.
4		PSII is comprised of photosynthetic pigments, electron carriers and the P700 reaction center.
5		The stroma is acidic relative to the inter-membrane space
6		A proton gradient provides the energy needed to synthesize ATP by in the ATPase coupling factor.
7		Rubisco is the enzyme that fixes carbon dioxide in the Calvin cycle.
8		The Calvin cycle must turn six times and fix six carbon dioxide molecules to yield one net glucose
9		The Calvin cycle occurs in the light.
10		The Z-scheme occurs in the dark.
11		The Calvin cycle requires ATP and NADPH that are supplied from the Z-scheme.
12		Plant can use green light for photosynthesis

Photosynthesis Question: On the equation below, draw a line from each atom on the left side of the equation to where the atom winds up on the right side of the equation.

ATP Question:
Explain why the thylakoids produced ATP in the experiment diagrammed below.

a. carotenes and xanthophylls	c. chlorophyll b only	e. all of the pigments
b. chlorophyll a only	d. chlorophyll a & b