Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochemistry > Photosynthesis > Flashcards

Photosynthesis Flashcards

1
Q

The region of the chloroplast between the inner membrane and the thylakoid membrane is called
a. the stroma.
b. the thylakoid space.
c. the intermembrane space.
d. the grana.

A

a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In chloroplasts,
a. the light reactions take place in the thylakoid disks, whereas the dark reactions occur in the stroma
b. the dark reactions take place in the thylakoid disks, whereas the light reactions occur in the stroma
c. the light reactions take place in the thylakoid space, whereas the dark reactions occur in the stroma
d. the dark reactions take place in the thylakoid space, whereas the light reactions occur in the stroma
e. none of these

A

a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In which part of the chloroplast does production of oxygen during photosynthesis primarily occur?
a. Grana.
b. Thylakoid disks.
c. Stroma.
d. Thylakoid space.
e. It is not known where this reaction occurs in the chloroplast.

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In which part of the chloroplast does reduction of CO2 during photosynthesis primarily occur?
a. Grana.
b. Thylakoid disks.
c. Stroma.
d. Thylakoid space.
e. It is not known where this reaction occurs in the chloroplast.

A

c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Accessory pigments
a. transfer electrons to reaction center chlorophylls.
b. transfer energy to reaction center chlorophylls.
c. transfer electrons from reaction center chlorophylls to phaeophytins.
d. transfer electrons from reaction center chlorophylls to ferredoxin.
e. All of these statements are true.

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Photosynthetic bacteria which do not use water as the ultimate source of electrons
a. only contain chlorophyll a.
b. only contain chlorophyll b.
c. do not produce oxygen.
d. have two photosystems.
e. none of these

A

c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The key element at the center of chlorophyll is
a. chlorine.
b. copper.
c. iron.
d. magnesium.
e. manganese.

A

d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Cyanobacteria contain
a. only chlorophyll a.
b. only chlorophyll b.
c. both chlorophyll a and chlorophyll b.
d. bacteriochlorophyll.
e. no chlorophyll at all

A

a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Two different types of chlorophyll are used by most plants for the following reason:
a. Two chlorophylls allow for absorbing light from a larger portion of the light spectrum.
b. The different chorophylls are used in different parts of the photosynthesis process.
c. One type is used in photosystem I and the other in phototsystem II.
d. The different chlorophylls are located in different compartments of the chloroplast.
e. It is not know why there are two different chlorophylls.

A

a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Wavelengths of what color are mostly responsible for the reactions in the light phase of photosynthesis?
a. Blue.
b. Green.
c. Red
d. Blue and red.
e. All three colors.

A

d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Green plants contain
a. only chlorophyll a.
b. only chlorophyll b.
c. both chlorophyll a and chlorophyll b.
d. bacteriochlorophyll.
e. chlorophyll a, chlorophyll b, and bacteriochlorophyll

A

c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which of the following is true concerning chlorophyll?
a. It abosrbs green light, which is why leaves are green
b. Chlorophyll a and b each have peaks of absorption at two different wavelengths
c. Chlorophyll a has a maximum absorption at 600 nm
d. Between the two chlorophylls, light is absorbed between 400 and 700 nm
e. none of these

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Chlorophyll differs from heme because it
a. has a cyclohexene ring fused to the tetrapyrrole ring system.
b. has a 16-carbon unbranched side chain.
c. contains magnesium rather than iron.
d. has a fully saturated tetrapyrrole ring.
e. none of these

A

c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

While chlorophyll contains a different metal ion, its ring structure is very similar to the ring structure in steroids.
a. True
b. False

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Light with short wavelengths has less energy than light with long wavelengths.
a. True
b. False

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

A specialized pair of chlorophylls exists at
a. the antenna complexes.
b. the accessory pigments.
c. the reaction centers.
d. the stroma.
e. the bottom of the roots in most plants

A

c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The light reactions drive the redox process that involves the following pairs of reactants/products
a. H2O/O2 and NADP+
/NADPH
b. H2O/O2 and NADH/NAD+
c. O2/H2O and NADPH/NADP+
d. H2O/O2 and FAD/FADH2

A

a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which of the following is not a component of the electron transport chain that links Photosystem I and Photosystem
II?
a. NADPH
b. pheophytin
c. plastoquinone
d. cytochrome f

A

a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The light phase of photosynthesis is closest to which other metabolic process?
a. Anaerobic Glycolysis.
b. The Pentose Monophosphate Pathway.
c. The Kreb’s Cycle.
d. The Electron Transport System
e. The reactions in the light phase are not similar to any other pathway.

A

d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

The process of ATP synthesis in chloroplasts is referred to as
a. oxidative phosphorylation.
b. photophosphorylation
c. reductive phosphorylation
d. substrate-level phosphorylation.
e. none of these

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which of the following statements concerning the light reactions of photosynthesis is false?
a. Photophosphorylation results from the proton gradient across the thylakoid membrane.
b. Photosystem II is devoted to water oxidation.
c. P700 is Photosystem II.
d. Photosystem I is devoted to NADP+
reduction.

A

c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The transfer of electrons from water to NADP+
to produce oxygen and NADPH is a highly exergonic process.
a. True
b. False

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The terminal electron acceptor during the light phase of photosynthesis in green plants is

a. Hydrogen (H2 → H2O).
b. NAD+ ( → NADH).
c. NADP+ ( → NADPH).
d. Oxygen (O2 → H2O).
e. Sulfur ( → H2S).

A

c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Which of the following statements concerning the light reactions of photosynthesis is false?
a. There are two photosystems linked by an electron transport chain
b. Electron transport is coupled to production of ATP
c. The production of NADPH is carried out by Photosystem I, whereas the splitting of water is carried out by
Photosystem II
d. Carbon dioxide fixation takes place

A

d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Light energy absorbed in chloroplasts is used in the light phase for all of these reactions, except:
a. To reduce water.
b. To make ATP.
c. To generate NADPH.
d. To reduce water and to generate oxygen, O2.
e. All of these occur during the light phase.

A

d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

The oxygen evolving complex consists of
a. accessory pigments.
b. a manganese-containing protein.
c. the reaction center chlorophylls.
d. ferredoxin.
e. none of these

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

The electrons used in photosynthesis come first from this molecule or atom:
a. Hydrogen (H2).
b. Manganese atom (Mn).
c. NADPH
d. Oxygen (O2).
e. Water (H2O).

A

e

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The reactions during the light phase of photosynthesis include the following:
1. Light absorption in photosystem I
2. Light absorption in photosystem II
3. Formation of O2 from water
4. Formation of NADPH
5. Formation of ATP

The order of the reactions is as follows:

a. 4 → 2 → 3 → 1 → 5.
b. 3 → 2 → 5 → 1 → 4.
c. 3 → 1 → 5 → 2 → 4.
d. 4 → 1 → 5 → 2 → 3.
e. 5 → 2 → 4 → 1 → 3.

A

b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Which of the following correctly describes a major difference between pheophytins and chlorophylls?
a. Pheophytins contain iron in their centers while chlorophylls contain magnesium.
b. Chlorophylls contain iron in their centers while pheophytins contain magnesium.
c. Pheophytins contain no metal ion in their centers.
d. Pheophytins aren’t at all like chlorophylls, but are quinones.
e. none of these

A

c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Which of the following statements concerning the photosynthetic reaction center of Rhodopseudomonas viridis is
false?
a. There is a pair of chlorophylls in a special environment.
b. Accessory pigments play a role in trapping of light.
c. A separation of charge represents stored energy.
d. The electrons being transferred can take either of two possible paths.

A

d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Which of the following is true?
a. A protein with a manganese ion is key to the conversion of O2 to water
b. The electron transport chain in photosynthesis is identical to the one in mitochondria
c. Parts of the electron transport chain in photosynthesis are similar to the electron transport chain in
mitochondria
d. Photosynthesis is the exact opposite of respiration
e. none of these

A

c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Which of the following is the mobile electron carrier from Photosystem II to the cytochrome b6f complex?
a. cyctochrome c
b. pheophytin
c. plastocyanin
d. ferredoxin
e. none of these

A

e

33
Q

During cyclic electron transport
a. only Photosystem II is involved.
b. only Photosystem I is involved.
c. both photosystems are involved.
d. neither photosystem is involved.

A

b

34
Q

During Z-scheme photosynthesis, ferredoxin oxidizes NADPH.
a. True
b. False

A

b

35
Q

Ferredoxin is important in photosynthesis in forming NADH.
a. True
b. False

A

b

36
Q

It is believed that the ratio of cyclic electron transport to Z-scheme photosynthesis changes in response to metabolic
demands. If a plant were actively synthesizing starch from the glucose produced, how would it alter these processes
compared to a plant just performing the Calvin cycle to produce glucose?
a. More cyclic photophosphorylation, less Z-scheme.
b. More Z-scheme photosynthesis, less cyclic photophosphorylation.
c. No significant difference.
d. Impossible to predict from the information provided.

A

a

37
Q

It is believed that the ratio of cyclic electron transport to Z-scheme photosynthesis changes in response to metabolic
demands. If a plant were using the C4 Hatch-Slack pathway, how would it alter these processes compared to a plant just
performing the standard C3 Calvin cycle to produce glucose?
a. More cyclic photophosphorylation, less Z-scheme.
b. More Z-scheme photosynthesis, less cyclic photophosphorylation.
c. No significant difference.
d. Impossible to predict from the information provided.

A

a

38
Q

It is believed that the ratio of cyclic electron transport to Z-scheme photosynthesis changes in response to metabolic
demands. If a plant were actively engaged in a large amount of reductive biosynthesis, requiring NADPH, how would it
alter these processes compared to a plant just performing the Calvin cycle to produce glucose?
a. More cyclic photophosphorylation, less Z-scheme.
b. More Z-scheme photosynthesis, less cyclic photophosphorylation.
c. No significant difference.
d. Impossible to predict from the information provided.

A

b

39
Q

While actively engaging in photosynthesis under illumination,
a. the pH of the thylakoid space would be lower than that of the stroma.
b. the pH of the thylakoid space would be greater than that of the stroma.
c. the pH of the thylakoid space and of the stroma would be about the same.
d. it would be impossible to predict the relative pH’s of the thylakoid space and of the stroma.

A

a

40
Q

The synthesis of ATP in chloroplasts uses a proton gradient similar to the one used in mitochondria.
a. True
b. False

A

a

41
Q

The ATP synthase in photosynthesis is similar in structure and function to its mitochondrial counterpart.
a. True
b. False

A

a

42
Q

The production of ATP in photosynthesis
a. is not linked to a proton gradient across a membrane
b. does not involve membrane-bound proteins
c. does not require the presence of light
d. provides the energy for production of sugars
e. occurs only in the dark

A

d

43
Q

Anaerobic, photosynthetic bacteria differ from green plants in that they only have one type of chlorophyll.
a. True
b. False

A

b

44
Q

Bacterial products of photosynthesis, other than oxygen and sugars, can include all of these, except:
a. H2S
b. NH3
c. CH4
d. Water
e. All of these are products of photosynthetic bacteria.

A

d

45
Q

The earliest photosynthetic organisms most likely used water as an electron source.
a. True
b. False

A

b

46
Q

After the reaction with Rubisco, the major difference between the Calvin Cycle and gluconeogenesis in liver is the
following reaction:
a. The reduction of 1,3 bisphosphoglyceric acid uses NADPH instead of NADH
b. The formation of 1,3 bisphosphoglyceric acid from 3-phosphoglyceric acid uses GTP instead of ATP.
c. Phosphatases are not required in plants.
d. The reduction of 1,3 bisphosphoglyceric acid uses NADH instead of NADPH
e. More than one of these reactions is substantially different in plants compared to liver.

A

a

47
Q

Where does the actual CO2 fixation process takes place?
a. the stroma.
b. the thylakoid space.
c. the intermembrane space.
d. the cytosol.
e. none of these

A

a

48
Q

The dark phase of photosynthesis is closest to this other metabolic process:
a. Anaerobic Glycolysis.
b. The Pentose Phosphate Pathway.
c. The Kreb’s Cycle.
d. The Electron Transport System
e. The reactions in the dark phase are not similar to any other pathway.

A

b

49
Q

The actual CO2 fixation process in photosynthesis is the addition of CO2 into a 5 carbon compound to yield
a. ribulose 5-phosphate.
b. ribulose 1,5-bisphosphate.
c. erythrose 4-phosphate.
d. 3-phosphoglycerate.
e. glucose 6-phosphate

A

d

50
Q

The enzyme ribulose 1,5-bisphosphate carboxylase
a. consists of eight catalytic subunits encoded by a chloroplast and eight regulatory subunits encoded by a
nuclear gene.
b. is difficult to isolate and study because it occurs in small amount in plant cells.
c. is nonallosteric.
d. is not involved in reactions linked to oxygen.

A

a

51
Q

The Calvin Cycle for CO2 fixation uses most of the same reactions as the pentose phosphate pathway.
a. True
b. False

A

a

52
Q

In the first reaction of carbon dioxide fixation in photosynthesis, CO2 reacts with
a. ribulose 5-phosphate.
b. ribulose 1,5-bisphosphate.
c. ribose 5-phosphate.
d. xylulose 5-phosphate.
e. glyceraldehyde 3-phosphate

A

b

53
Q

After the CO2 fixation step in photosynthesis, the production of sugars takes place
a. as a reversal of glycolysis.
b. as a reversal of the citric acid cycle.
c. in the same manner as gluconeogenesis.
d. as a reversal of the pentose phosphate pathway.
e. the same as in glycolysis

A

c

54
Q

For the net synthesis of one six-carbon sugar from CO2 in photosynthesis there is a requirement for
a. 12 ATP and 12 NADPH.
b. 18 ATP and 18 NADPH.
c. 12 ATP and 18 NADPH.
d. 18 ATP and 12 NADPH.

A

d

55
Q

The fixation of CO2 to form sugars requires the following:
a. Oxygen, O2.
b. ATP.
c. NADPH.
d. Both ATP and NADPH.
e. All 3 of these are required to convert CO2 to sugar.

A

d

56
Q

In the Calvin cycle a reshuffling of intermediates is necessary
a. to ensure uniform incorporation of CO2 into newly synthesized sugars
b. to regenerate the key intermediate with which CO2 initially reacts
c. to use as little ATP as possible
d. to use as little NADPH as possible

A

b

57
Q

Which of these statements concerning the Calvin Cycle is false?
a. There is significant overlap between these reactions and glycolysis.
b. During the process, ATP is used with an ADP product.
c. Fructose 1,6 bisphosphate is an intermediate in this pathway.
d. NADP+
is converted to NADPH during this pathway.
e. At least one reduction reaction occurs during this pathway

A

d

58
Q

The efficiency of energy use in photosynthesis is approximately
a. 99%
b. 65%
c. 30%
d. 2%

A

c

59
Q

The stoichiometric balance of the Calvin Cycle has 6 ribulose 1,5 bisphosphate and 6 CO2 forming twelve 3-
phosphoglycerate. Of these 12 molecules, two are used to make glucose and the other ten are used to regenerate the
ribulose 1,5 bisphosphate.
a. True
b. False

A

a

60
Q

The nuclear gene for Rubisco codes for the catalytic subunit, while the regulatory gene is found in the chloroplast.
a. True
b. False

A

b

61
Q

After the formation of 3-phosphoglyceric acid, the reactions in the dark phase of photosynthesis are essentially the
same as those in gluconeogenesis.
a. True
b. False

A

b

62
Q

The enzyme, ribulose 1,5 bisphosphate carboxylase (Rubisco), is:
a. one of the most abundant proteins in nature.
b. about 15% of the protein content of the chloroplast
c. a multisubunit enzyme
d. consistent with the endosymbiotic origin for organelles such as chloroplasts and mitochondria
e. all of these

A

e

63
Q

Rubisco is a rare example of an enzyme whose genetic information is found in two different cellular compartments.
a. True
b. False

A

a

64
Q

In order to regenerate ribulose 1,5 bisphosphate, the following reaction is required:
a. A phosphate group must be added to ribulose-1-phosphate.
b. The enzyme involved is phosphoribulose kinase.
c. ATP is used as a source of phosphate.
d. Both phosphoribulose kinase and ATP are needed.
e. All of these statements are true.

A

a

65
Q

The essential enzyme for the C4 pathway is
a. ribulose bisphosphate carboxylase:oxygenase
b. phosphoenolpyruvate carboxylase
c. ferredoxin-thioredoxin reductase
d. glyoxylate oxygenase
e. none of these

A

b

66
Q

Which of the following is NOT an intermediate in the C4 pathway?
a. phosphoenolpyruvate
b. oxaloacetate
c. malate
d. fumarate

A

d

67
Q

The C4 pathway for carbon dioxide fixation has what requirement compared to the Calvin cycle?
a. requires more ATP
b. requires less ATP
c. requires more NADPH
d. requires less NADPH
e. none of these

A

a

68
Q

In plants that use the C4 pathway there is less likelihood for the occurrence of which process compared to plants that
rely exclusively on the Calvin cycle?
a. gluconeogenesis
b. photorespiration
c. the pentose phosphate pathway
d. lipid anabolism

A

b

69
Q

Of the two photosynthetic pathways, Calvin Cycle or Hatch-Slack Pathway, only the Calvin Cycle uses the pentose
phosphate pathway.
a. True
b. False

A

a

70
Q

One very important reason for the Hatch-Slack Pathway of photosynthesis is to increase the concentration of CO2 in
the chloroplast.
a. True
b. False

A

a

71
Q

The Hatch-Slack Pathway is important in tropical zones since, in order to conserve water, the pores of tropical leaves
are very small.
a. True
b. False

A

a

72
Q

The first CO2 fixing reaction of the Hatch-Slack pathway is:
a. Conversion of phosphoenolpyruvate and CO2 to oxaloacetate.
b. Conversion of succinate and CO2 to α-ketoglutarate.
c. Conversion of acetate and CO2 to pyruvate.
d. Conversion of acetate and CO2 to malonate.
e. More than one of these reactions can initiate the Hatch-Slack Pathway.

A

d

73
Q

Presence of oxygen can poison the reaction of Rubisco, due to an alternate reaction in which the ribulose 1,5
bisphosphate is oxidized, rather than reacting with CO2
a. True
b. False

A

a

74
Q

Which of the following is not true regarding the C4 pathway?
a. The C4 pathway allows for the concentration of CO2
b. the KM for CO2 is lower with Rubisco than for phosphoenolpyruvate carboxylase
c. Rubisco also has an oxygenase activity that appears to be a wasteful process in terms of energy production
d. The C4 pathway alleviates some of the wastefulness of the oxygenase activity of Rubisco by concentrating
CO2 in the interior of the plant.

A

b

75
Q

Explain the significance of thylakoid disks in the process of photosynthesis.

A

Thylakoid disks are contained within chloroplasts and function as sites for a light-trapping reaction.
They are formed by the folding of a third membrane within the chloroplast. The folding of the
thylakoid membrane creates two spaces in the chloroplast in addition to the intermembrane space.
The stroma lies within the inner membrane and outside the thylakoid membrane. In addition to the
stroma, there is a thylakoid space within the thylakoid disks. The trapping of light and the
production of oxygen take place in the thylakoid disks. The dark reactions, in which CO2 is fixed to
carbohydrates, take place in the stroma.

76
Q

Which of the following types of bacteria contain bacteriochlorophylls, but do not use water as the ultimate source of electrons for the redox reactions of photosynthesis and do not produce oxygen?

a. Acidobacteria and cyanobacteria
b. Green and purple sulfur bacteria
c. Chlamydiae and fusobacteria
d. Spirochaetes and actinobacteria

A

b

77
Q

Which of the following types of chlorophyll increases the portion of the visible spectrum that is absorbed and thus
enhances the efficiency of photosynthesis in green plants compared with cyanobacteria?
a. Chlorophyll a
b. Chlorophyll b
c. Chlorophyll c
d. Chlorophyll d

A

b

78
Q

Which of the following is a similarity between light reaction and dark reaction?
a. Both reactions fix CO2.
b. Both reactions split water into hydrogen and oxygen.
c. Both reactions carry out redox reactions.
d. Both reactions involve the Calvin cycle.

A

c

79
Q

_____ is a photosynthetic pigment that differs from chlorophyll only in having two hydrogens atoms in place of one
magnesium atom.
a. Phycobiliprotein
b. Bacteriorhodopsin
c. Xanthophyll
d. Pheophytin

A

d

Biochemistry (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions