Chapter 5: Energy and Photosynthesis

Question 1

Why do plants look green to us?

1. The pigments they contain absorb all colors of light wavelengths except green.
2. The only type of pigment they contain is green.
3. The chemical reactions of photosynthesis turn plants green.
4. Green is the only light wavelength that can be used in photosynthesis.

Answer 1

The pigments they contain absorb all colors of light wavelengths except green.

Question 2

Every time a source of energy is converted from one form to another:

1. the total energy of the system increases.
2. the total amount of energy in the universe is reduced by a tiny amount.
3. some of the energy is converted to heat, which is one of the least usable forms of kinetic energy.
4. the first law of thermodynamics is violated.
   5.the entropy in the system is reduced.

Answer 2

some of the energy is converted to heat, which is one of the least usable forms of kinetic energy

Question 3

The most abundant protein in the world is the enzyme that initiates the fixation of carbon in the Calvin cycle. This enzyme is called:
Correct Answer
1. rubisco.
2. ribulose biphosphate.
3. ATP-synthase.
4. glyceraldehyde-3-phosphate.
5. crassulacean acid.

Answer 3

rubisco

Question 4

A green plant can carry out photosynthesis if given nothing more than:

1. water.
2. light.
3. water, light, and air.
4. water and light.
5. air.

Answer 4

water, light, and air.

Question 5

Which of the following sequences accurately represents the flow of electrons during photosynthesis (in order)?

1. NADPH → O2 → CO2
2. NADPH → chlorophyll → Calvin cycle
3. NADPH → electron transport chain → O2
4. H2O → NADPH → Calvin cycle
5. Calvin cycle → H2O → ATP

Answer 5

H2O → NADPH → Calvin cycle

Question 6

Both the first and the second photosystems are ultimately responsible for:

1. generating energy-storage molecules.
2. generating ADP.
3. generating oxygen.
4. generating photonic energy.
5. generating CO2.

Answer 6

generating energy-storage molecules

Question 7

What is chlorophyll?

1. It is the plant organelle in which photosynthesis takes place.
2. It is one of the openings on the bottom of a leaf through which CO2 enters.
3. It is the green pigment that enables plants to convert light energy to chemical energy.
4. It maintains the hydrogen ion concentration gradient that makes ATP production possible.

Answer 7

It is the green pigment that enables plants to convert light energy to chemical energy

Question 8

Oxygen gas produced during photosynthesis originates as:

1. oxygen atoms are released by the metabolism of carbohydrates.
2. oxygen atoms contained in carbon dioxide are released when the carbon is fixed.
3. a by-product of nitrogen-fixing bacteria.
4. a molecule of chlorophyll oxidized by a photon.
5. oxygen atoms contained in water molecules.

Answer 8

oxygen atoms contained in water molecules

Question 9

Photons excite electrons in chlorophyll during the first photosystem that occurs. These electrons are then trapped by the primary electron acceptor. How does the reaction center chlorophyll replace these that were lost to the primary electron acceptor?

1. These electrons are not replaced. A molecule of chlorophyll in a photosystem is used up with each electron transferred.
2. The photosystem replaces its light-excited electrons by extracting electrons from carbon dioxide.
3. The photosystem replaces its light-excited electrons by extracting electrons from the electron transport chain.
4. The photosystem replaces its light-excited electrons by extracting electrons from water.
5. The photosystem replaces its light-excited electrons by extracting electrons from oxygen.

Answer 9

The photosystem replaces its light-excited electrons by extracting electrons from water

Question 10

Bubbles come from the leaves of an Elodea plant when it is put under water because:

1. oxygen and carbon dioxide diffuse out of vacuoles when vacuole pressure is reduced.
2. thylakoids become depressurized and release nitrogen gas.
3. oxygen is a by-product of photosynthesis.
4. the cell wall is permeable to the gases released by the stomata.
5. due to anaerobic conditions underwater, the plant must resort to fermentation, causing the production of excess carbon dioxide.

Answer 10

oxygen is a by-product of photosynthesis

Question 11

The phosphate groups in ATP:

1. are covalently bonded to each other.
2. represent a significant source of stored energy.
3. are negatively charged.
4. release energy when separated from the rest of the molecule.
5. All of the above are correct.

Answer 11

All of the above are correct

Question 12

Which of the following is NOT a product of photosynthesis?

1. glucose
2. oxygen
3. sugars
4. carbon dioxide
5. None of the above; all are products of photosynthesis.

Answer 12

carbon dioxide

Question 13

During photosynthesis, visible light has enough energy to directly:

1. excite electrons.
2. synthesize NADPH.
3. convert ADP into ATP.
4. reflect light in the red spectrum.
5. split a water molecule into hydrogen and oxygen.

Answer 13

excite electrons

Question 14

“The process by which water, carbon dioxide, and light energy are converted into glucose and oxygen” defines which of the following?

1. cellular respiration
2. global warming
3. the Calvin cycle
4. photosynthesis

Answer 14

photosynthesis

Question 15

During the Calvin cycle, rubisco’s function is to:

1. regenerate RuBP (ribulose bisphosphate) molecules for carbon fixation.
2. catalyze the addition of glyceraldehyde-3-phosphate to acetyl-CoA.
3. reduce NADPH.
4. combine CO2 to RuBP (ribulose bisphosphate).
5. form RuBP (ribulose bisphosphate) while releasing ATP.

Answer 15

combine CO2 to RuBP (ribulose bisphosphate)

Question 16

The chlorophyll pigments found in green leaves absorb what color(s) of light?

1. green
2. red
3. green and blue
4. blue and red

Answer 16

blue and red

Question 17

Which of the following products of the “Photo” reactions of photosynthesis are later employed in the Calvin cycle?

1. ADP and RuBP
2. NADPH and ATP
3. NADPH and ADP
4. free oxygen and water
5. NADP+ and ATP

Answer 17

NADPH and ATP

Question 18

Which of the following does NOT occur during the Calvin cycle?

1.consumption of ATP
2. oxidation of NADPH
3. splitting of water
4. consumption of carbon dioxide
5. carbon fixation

Answer 18

splitting of water

Question 19

A plant whose leaves are reddish-yellow is NOT absorbing light from which wavelengths of the visible-light spectrum?

1. red and yellow
2. green, red, and yellow
3. blue and violet
4. green and red
5. green and yellow

Answer 19

red and yellow

Question 20

Potential energy:

1. is stored energy available to do work.
2. transfers motion to matter.
3. is contained in matter placed in certain positions or arrangements within nuclei of atoms.
4. contains less energy than kinetic energy.
5. is the energy of motion.

Answer 20

is stored energy available to do work