photosynthesis outline Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

what did van Helmont do? what did he find out?

A

he planted a 5 lb plant in 200 lbs of soil and gave it H20 for 5 years. the tree gained 165 lbs, but the soil only lost 2 oz. he concluded plant’s mass comes from water, not soil (incorrect)

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

what did Joseph Priestly do? what did he found out

A

covered a candle with a closed contained and found that it burned out. but when he added a mint plant to it, the candle continued to burn. he concluded that the mint “restored” the air that the burning candle depleted without knowing of O2

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

what did Ingenhouse do?

A

discovered plants needed light, finishing the photosynthesis mystery

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

what is photosynthesis?

A

process by which autotrophs use light energy and convert it to chemical energy to make glucose molecules from carbon dioxide and water

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

where is chemical energy stored?

A

stored in C-C C-H bonds in glucose

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

equation for photosynthesis

A

6CO2 + 6 H2O+ (6 H2O) + light —> 6O2 + (6H20) + C6H1206

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

what carries out photosynthesis in plants? where are they located?

A

chloroplasts in green parts of plants

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

where are most chlorophylls located?

A

leaves

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

where do plants get their green color from?

A

chlorophyll pigment

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

where is chlorophyll found?

A

interior layer called mesophyll

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

where do CO2 and H2O enter plants from?

A

stomata

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

disk like sacs

A

thylakoid

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

stack of thylakoids

A

grana

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

thick fluid inside inner membrane

A

stroma

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

where are chlorophyll molecules found?

A

inside thylakoid membranes

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

xylum

A

H2O transport vein

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

phloem

A

sucrose transport vein

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

layers of a leaf

A

upper epidermis
mesophyll,
guard cell, stomate
lower epidermis

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

what type of process is photosynthesis?

A

redox process

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

what is oxidized and reduced in photosynthesis? what happens as a result?

A

water - oxidized
carbon dioxide - reduced
electrons gain energy

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

what provides energy for electrons to go up the energy hill?

A

light energy captured by chlorophyll molecules

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

pathway of energy

A

solar/light energy –> chemical energy/ATP—> energy stored in glucose

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

what type of energy is sunlight?

A

radiation or electromagnetic energy

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

what light can we see?

A

visible/white light

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

what happens as light hits a cholorplast?

A

pigment molecules in the thylakoids absorb different wavelengths of light

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

what light does chlorophyll a absorb?

A

mainly blue-violet and red light, and reflects green light

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

what does chlorophyll b absorb?

A

mainly blue and orange, and reflects yellow-green

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

cartenoids

A

family of orange colored pigments
carrots, tomatoes, fall leaves

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

what do chlorophyll b and carotenoids do in photosynthesis?

A

don’t directly participate in the reactions
broaden the range of light a plant can use and then pass the light energy they absorb onto chlorophyll a

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

what does chlorophyll a do in photosynthesis?

A

put the energy received to work in photosynthesis

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

correlation bw wavelength and amount of energy?

A

inverse
long wavelength=lower energy
short wavelength=high energy

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

high energy to low

A

gamma rays (V)
radiowaves (R)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

how many stages does does photosynthesis have?

A

light dependent
light independent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what are the light reactions?

A

reactions that require light directly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what do light reactions do? what is this known as?

A

reactions that convert solar energy to chemical energy and produce 1/2 O2 as a waste product
“photo” part of photosynthesis as it takes energy from light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

where does the light reactions of photosynthesis occur?

A

in the thylakoid membrane of the chloroplast’s grana

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what does noncyclic phosphorylation use?

A

light (photo-)
ADP +Pi (phosphorylation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what are photons?

A

discrete packets of energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what can light behave as?

A

waves or photons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what happens when a pigment molecule absorbs a photon?

A

one of the pigment’s electrons gains energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what does the electron that has gained energy do?

A

raised from the ground state to an excited stae and immediately loses that excess energy as it it unstable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

what is the excess energy released as? (3)

A

heat
fluorescence
passed to primary electron acceptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

fluorescence

A

light that is emitted as an electron falls from excited to ground state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

how are all pigments in the thylakoid membrane grouped?

A

clusters of 200-300 pigment molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what donates electrons to the primary electron acceptor?

A

only one chlorophyll a molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

reaction center

A

chlorophyll a and primary electron acceptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

what does chlorophyll a pigments and other pigments molecules act as?

A

function together as light gathering antennae that absorb photons and pass the energy along the pigment molecules until it reaches the reaction center

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

photosystme

A

combination of antenna pigment molecules, reaction center, and primary electron acceptor

49
Q

2 types of photosystems in light reactions

A

photosystem II and I

50
Q

what is the name of chlorophyll a name in photosystem II? why?

A

P680 as the wavelength it absorbs best is 680 nm (orangish-red)

51
Q

what is the name of chlorophyll a name in photosystem I? why?

A

P700 as the wavelength it absorbs best is 700 nm (red)

52
Q

what happens to each primary electron acceptor after it gains electrons?

A

gets oxidized as it loses as electron down the ETC

53
Q

what is the energy lost down the electron transport chain used to do in photosystem II?

A

make ATP

54
Q

what happens to this energy lost down the ETC used to do in photosystem I?

A

temporarily stored in the coenzyme NADPH

55
Q

reaction for NADPH production

A

NADP+ + 2e- + H+ —> NADPH

56
Q

what does every molecule of NADPH need to form?

A

2 electrons from photosystem I

57
Q

where does photosystem I get its electrons?

A

from the bottom of the first ETC

58
Q

where does photosystem II get its electrons?

A

photolysis - splitting of H2O
it leaves behind 2 H+ and 1/2 O2

59
Q

what does the waste oxygen atom do?

A

combines with another oxygen atom to make O2 that will be released from the stomata that guard cells let them through from

60
Q

stomata

A

opening of the bottom of leaf

61
Q

what are the products of light reactions?

A

ATP, NADPH, 1/2 O2

62
Q

how are NADPH and the O2 waste products formed?

A

redox reactions in the thylakoids

63
Q

how is ATP formed in light reactions?

A

chemiosmosis

64
Q

summary equation for light reaction

A

H2O + light +ADP + Pi + NADP+ + 2e- + H+ —-> 1/2 O2 + 2e- + 2H+ + ATP + NADPH

65
Q

what drives the H+ from the stroma to the lumen of the thylakoid? what does this create?

A

energy released during the ETC;
H+ gradient with potential energy to drive ATP synthesis

66
Q

photophosphorylation

A

making of ATP

67
Q

what is the final electron acceptor in 2nd ETC?

A

NADP+ not O2

68
Q

difference between cyclic phosphorylation and non cyclic phosphorylation?

A

cyclic uses a simpler pathway to generate ATP and is only used when NADP+ is not around to accept electrons, so it’s not as efficient

69
Q

function diff between cyclic and noncyclic?

A

electrons in photosystem I are excited like normal and leave P700, onto to be passed along the ETC of photosystem II and returned back to P700

70
Q

the calvin cycle different names

A

calvin-benson cycle
light-independent reactions
dark reactions
C3 photosynthesis

71
Q

purpose of calvin cycle

A

make glucose

72
Q

where does the calvin cycle take place?

A

stroma of the chloroplast

73
Q

what does the calvin cycle require?

A

CO2 from the air
ATP and NADPH made in the light reactions

74
Q

what is the energy to make sugar in the calvin cycle?

A

ATP and NADPH

75
Q

what is the carbon source for the calvin cycle?

A

CO2 molecules

76
Q

what does the Calvin cycle do with the CO2

A

carbon fixation - fixes it from the air and converts it into carbohydrates

77
Q

how many spins does it take to make a 6 C glucose from the calvin cycle?

A

must repeat 6 times as it takes in only one CO2

78
Q

how many spins does it take to make 1 PGAL molecule?

A

3- 3CO2 molecules are needed

79
Q

how many PGAL molecules are needed to make glucose?

A

2 to make 1

80
Q

what happens once CO2 enters the calvin cycle in the stroma?

A

combines with a 5 C molecule called RuBP (ribulose biphosphate) to form an unstable 6 C compound with the aid of rubisco-an enzyme

81
Q

what happens to this 6 C compound?

A

quickly breaks down into 3 carbon compound 3-PGA (phosphoglycerate)

82
Q

why is the calvin cycle also called C3 photosynthesis?

A

first stable product formed is 3 carbon PGA molecule

83
Q

how are ATP and NADPH used?

A

for each spin 2 ATP and 2 NADPH are oxidized to produce energy rich 3 carbon molecule called PGAL (Phosphoglyceraldehyde) / G3P (glyceraldehyde 3-phosphate)

84
Q

when does PGAL leave the cycle?

A

until 3 spins are made

85
Q

how many PGALs are made in one spin?

A

1

86
Q

if 3 CO2 enter the calvin cycle, how many intermediates are there? 3-PGA? ATP? NADPH? PGAL/G3P?

A

3 six carbon intermediates
6 3-PGA
6 ATP
6 NADPH
6 PGAL/G3P

87
Q

what happens when one PGAL leaves the cycle?

A

the other 5 with the aid of 3 ADP is converted back to 5 carbon RuBP continuing the cycle

88
Q

how many times does the carbon cycle happen?

A

x2
it takes 3 CO2 to release 1 PGAL
so 6 CO2 to release 2 PGAL
that will make one glucose

89
Q

what can the 2 PGALS make beside glucose?

A

fructose or sucrose
or make many glucoses to make starch or cellulose

90
Q

do the reactions in the calvin cycle occur spontaneously?

A

no-enzymes catalyze every product in photosynthesis
coenzymes and cofactors are also involved

91
Q

coenzyme

A

organic - NADPH

92
Q

cofactor

A

inorganic - metal ions

93
Q

what do cofactors and coenzymes do?

A

fit in active site for other substances to bind

94
Q

how does the calvin cycle use light?

A

although it is called the dark reaction, it used light indirectly as it dependents of ATP and NADPH made in light reactinos

95
Q

equation for calvin cycle?

A

6CO2 + 18 ATP+ 12 NADPH–> C6H1206 + 18 ADP + 18Pi + 12 NADP+ +12H+ + 24e-

96
Q

C3 plants. examples?

A

plants in which the Calvin cycle used CO2 directly from the air and first compound made is 3-PGA
wheat, rice, oats

97
Q

what is the problem with C3 plants?

A

in hot dry days, they close their stomata to prevent H2O loss, but also blocks CO2 from entering and O2 from leaving

98
Q

what happens as CO2 levels get down and O2 get up in C3 plants?

A

C3 photorespiration occurs - rubisco incorporates O2 instead of CO2

99
Q

how is photorespiration different from photosynthesis? cellular respiration?

A

it yields no glucose; yields no ATP

100
Q

what is photorespiration believed to be?

A

an evolutionary relic when atmosphere had much less O2 and more CO2

101
Q

what does photorespiration drain away?

A

50% of the carbon fixed by the Calvin cycle and lowers crop yields

102
Q

what do C4 plants do?

A

their first product in the calvin cycle in a 4 C compound
keep stomata closed to prevent water loss, but still make glucose by photosynthesis

103
Q

what enzyme do C4 plants have? what does it do?

A

PEP carboxylase that fixes carbon into 4 C oxaloacetate instead of 3 C 3-PGA
this enzyme cannot fix O2, and can continue to fix carbon when CO2 levels are low

104
Q

what happens to oxaloacetate?

A

gets converted to malate then acts as a carbon shuttle which donates CO2 to a bundle sheath cell

105
Q

what is a bundle sheath cella?

A

cell which keeps making sugars even though the stomata are closed most of the time

106
Q

examples of C4 plants? how did these become C4?

A

corn, crab grass, sugar cane;
evolved in the tropics as it is advantageous

107
Q

what type of photosynthesis do C4 plants do?

A

C4 photosynthesis

108
Q

how is C4 photosynthesis separated?

A

spatially separated

109
Q

CAM

A

crassulacean acid metabolism
third mode of carbon fixation and water conservation

110
Q

CAM plants

A

pineapples, cacti, most succulent (very juicy tissue)
adapted to extremely dry climates

111
Q

what does a CAM plant do?

A

conserves water by opening its stomata and admitting CO2 only at night

112
Q

what happens when CO2 enters the leaves in CAM?

A

fixed into oxaloacetate during the night and then releases it as CO2 to the calvin cycle during the day, keeping photosynthessis operating during the day even when there isnt CO2

113
Q

where does C3 photorespiration take place?

A

mesophyll

114
Q

result of C3 photorespiration?

A

no sugar

115
Q

where does C4 photosynthesis take place?

A

makes 4C in mesophyll
makes sugar in bundle sheet

116
Q

result of C4 photosynthesis?

A

sugar

117
Q

where does CAM takes place?

A

4C during the night in mesophyll
sugar during the day in mesophyll

118
Q

results of CAM

A

sugar