Chapter 10- Photosynthesis Flashcards
The process of photosynthesis probably originated ________.
A) in plants
B) in prokaryotes
C) in fungi
D) three separate times during evolution
in prokaryote
If photosynthesizing green algae are provided with CO2 containing heavy oxygen(18O), later analysis will show that all of the following molecules produced by the algaecontain 18O EXCEPT ________.
A) 3-phosphoglycerate
B) glyceraldehyde 3-phosphate (G3P)
C) glucose
D) ribulose bisphosphate (RuBP)
E) O2
O2
Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?
A) CO2 and glucose
B) H2O and O2
C) ADP, i, and NADP+
D) electrons and H+
E) ATP and NADPH
ATP and NADPH
When oxygen is released as a result of photosynthesis, it is a direct by-product of________.
A) reducing NADP+
B) splitting water molecules
C) chemiosmosis
D) the electron transfer system of photosystem I
E) the electron transfer system of photosystem II
splitting water molecules
Which of the following statements best describes the relationship betweenphotosynthesis and respiration?
A) Respiration runs the biochemical pathways of photosynthesis in reverse.
B) Photosynthesis stores energy in complex organic molecules; respiration releases energy from complex organic molecules
C) Photosynthesis occurs only in plants; respiration occurs only in animals.
D) ATP molecules are produced in photosynthesis but not in aerobic respiration.
E) Photosynthesis is catabolic; respiration is anabolic.
photosynthesis stores energy in complex organic molecules; respiration releases energy from complex organic molecules
In photosynthetic cells, synthesis of ATP by the chemiosmotic mechanism occursduring ________.
A) photosynthesis only
B) respiration only
C) photosynthesis and respiration
D) neither photosynthesis nor respiration
E) photorespiration only
photosynthesis and respiration
Which of the following sequences correctly represents the flow of electrons duringphotosynthesis?
A) NADPH → O2 → CO2
B) H2O → NADPH → Calvin cycle
C) NADPH → chlorophyll → Calvin cycle
D) H2O → photosystem I → photosystem II
E) NADPH → electron transport chain → O
H2O → NADPH → Calvin cycle
Chlorophylls absorb most light in which colors of the visible range?
A) green and blue
B) blue and red
C) green and red
D) violet and red
blue and red
Which of the following is a difference between chlorophyll a and chlorophyll b?
A) Chlorophyll a is a pigment, and chlorophyll b is the enzyme that transfers excited electrons from chlorophyll a to electron carriers of the thylakoid membrane.
B) Chlorophyll an absorbs yellow light, and chlorophyll b absorbs green.
C) Chlorophyll a contains magnesium in its ring structure, whereas chlorophyll b contains iron.
D) Chlorophyll an and b absorb light energy at slightly different wavelengths.
Chlorophyll an and b absorb light energy at slightly different wavelengths
Why are there several structurally different pigments in the reaction centers of photosystems?
A) Excited electrons must pass through several pigments before they can be transferred to electron acceptors of the electron transport chain.
B) This arrangement enables the plant to absorb light energy of a variety of wavelengths.
C) They enable the plant to absorb more photons from light energy, all of which are at the same wavelength.
D) They enable the reaction center to excite electrons to a higher energy level.
This arrangement enables the plant to absorb light energy of a variety of wavelengths.
In autumn, the leaves of deciduous trees change colors. This is because chlorophyll is degraded and ________.
A) carotenoids and other pigments are still present in the leaves
B) the degraded chlorophyll changes into many other colors
C) water supply to the leaves has been reduced
D) sugars are sent to most of the cells of the leaves
carotenoids and other pigments are still present in the leaves
Energy from sunlight can excite electrons, kicking them out of their orbitals and creating free radicals. Free radicals are highly reactive atoms or molecules that have unpaired electrons and degrade and destroy other compounds in their vicinity. Carotenoids, one of the pigments present in most chloroplasts, can stabilize these free radicals. This suggests that ________.
A) once chloroplasts are destroyed, the free radicals will destroy the cell
B) carotenoids probably have a protective function in the cell
C) free radicals induce the synthesis of carotenoids in chloroplasts
D) carotenoids communicate directly with the immune system of plants
carotenoids probably have a protective function in the cell
What event accompanies energy absorption by chlorophyll (or other pigment molecules of the antenna complex)?
A) ATP is synthesized from the energy absorbed.
B) A carboxylation reaction of the Calvin cycle occurs.
C) Electrons are stripped from NADPH.
D) An electron is excited.
An electron is excited
Suppose a plant has a unique photosynthetic pigment and the leaves of this plant appear to be reddish yellow. What wavelengths of visible light are absorbed by this pigment?
A) red and yellow
B) blue and violet
C) green and yellow
D) blue, green, and red
E) green, blue, and yellow
blue and violet
Carotenoids are often found in foods that are considered to have antioxidant properties in human nutrition. What related function do they have in plants?
A) They serve as accessory pigments to increase light absorption.
B) They protect against oxidative damage from excessive light energy
C) They shield the sensitive chromosomes of the plant from harmful ultraviolet radiation.
D) They reflect orange light and enhance red light absorption by chlorophyll.
E) They take up and remove toxins from the groundwater.
They protect against oxidative damage from excessive light energy
Plants photosynthesize ________.
A) only in the light but respire only in the dark
B) only in the dark but respire only in the light
C) only in the light but respire in light and dark
D) and respire only in the light
E) and respire only in the dark
only in the light but respire in light and dark
The figure shows the absorption spectrum for chlorophyll a and the action spectrum for photosynthesis. Why are they different?
A) Green and yellow wavelengths inhibit the absorption of red and blue wavelengths.
B) Bright sunlight destroys photosynthetic pigments.
C) Oxygen given off during photosynthesis interferes with the absorption of light.
D) Other pigments absorb light in addition to chlorophyll a.
E) Aerobic bacteria take up oxygen, which changes the measurement of the rate of photosynthesis.
Other pigments absorb light in addition to chlorophyll a.
Theodor W. Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different segments of algae to different wavelengths of light. He added aerobic bacteria and then noted in which areas the bacteria congregated. He noted that the largest groups were found in the areas illuminated by the red and blue light. If you ran the same experiment as Engelmann without passing light through a prism, what would you predict?
A) The results would be the same
B) The bacteria would be relatively evenly distributed along the algal filaments.
C) The number of bacteria present would decrease due to an increase in the carbon dioxide concentration.
D) The number of bacteria present would increase due to an increase in the carbon dioxide concentration.
E) The number of bacteria would decrease due to a decrease in the temperature of the water.
The bacteria would be relatively evenly distributed along the algal filaments.
A spaceship is designed to support animal life for a multiyear voyage to the outer planets of the solar system. Plants will be grown to provide oxygen and to recycle carbon dioxide. Since the spaceship will be too far from the Sun for photosynthesis, an artificial light source will be needed. What wavelengths of light should be used to maximize plant growth with a minimum of energy expenditure?
A) full-spectrum white light
B) green light
C) a mixture of blue and red light
D) yellow light
E) UV light
a mixture of blue and red light
What wavelength of light in the figure is most effective in driving photosynthesis?
A) 420 mm
B) 475 mm
C) 575 mm
D) 625 mm
E) 730 mm
420 mm
The proteins of the electron transport chain active in the light-dependent reactions ________.
A) are membrane proteins present in the thylakoid
B) are free proteins present in the thylakoid lumen
C) are considered to be part of the reaction center of photosystem I
D) absorb the same wavelengths of light as their associated chlorophylls
are membrane proteins present in the thylakoid
What is the difference between NAD+ and NADP?
A) NAD+ functions as an electron transporter, whereas NADP does not.
B) NAD+ functions as a free-energy source for cells, whereas NADP does not.
C) Both function as electron carriers, but NADP has a phosphate group and NAD+ does not.
D) Both transport electrons to the electron transport chain (ETC) found on the inner mitochondrial membrane, but NADP transfers its electrons to the ETC at a higher energy level.
Both function as electron carriers, but NADP has a phosphate group and NAD+ does not.
As electrons are passed through the system of electron carriers associated with photosystem II, they lose energy. What happens to this energy?
A) It excites electrons of the reaction center of photosystem I.
B) It is lost as heat.
C) It is used to establish and maintain a proton gradient.
D) It is used to phosphorylate NAD+ to NADPH, the molecule that accepts electrons from photosystem I.
It is used to establish and maintain a proton gradient.
