Bio Chapter 8 Photosynthesis

Front 1

in the light-dependent reactions, photosystems in the _______ absorb photons and use this energy to generate ATP and NADPH

Back 1

thylakoid

Front 2

what replaces the electrons lost in the photosystems

Back 2

the oxidation of water

Front 3

the oxidation of water in phtosynthesis produces what?

Back 3

O2

Front 4

How is the ATP and NADPH used?

Back 4

used during carbon fixation via the calvin cycle in the stroma

Front 5

first two stages of photosynthesis that require light

Back 5

light-dependent reactions

Front 6

third stage of photosynthesis

Back 6

carbon fixation

Front 7

what occurs during carbon fixation?

Back 7

formaton of organic molecules from CO2

Front 8

how does the carbon fixation take place?

Back 8

via a cyclic series of reactions called the Calvin cycle

Front 9

does carbon fixation need light?

Back 9

no

Front 10

what does carbon fixation need?

Back 10

ATP and NADPH

Front 11

what is another name for the carbon fixation and calvin cycle?

Back 11

light-independent reactions

Front 12

equation of photosynthesis

Back 12

6CO2 + 12 H2O + sunlight --> C6H12O6 + 6 H2O + 6 O2

Front 13

internal membrane of chloroplasts

Back 13

thylakoid membrane

Front 14

the thylakoid membrane is a continuous phospholipid bilayer organized into flattened sacs that are found stacked on one another in columns called ______

Back 14

grana (singular, granum)

Front 15

a photosynthetic pigment that captures light energy to make ATP

Back 15

chlorophyll

Front 16

connections between grana

Back 16

stoma lamella

Front 17

semiliquid substance surrounding the thylakoid membrane

Back 17

stroma

Front 18

what does the stroma house

Back 18

the enzymes needed to create organic molecules from CO2

Front 19

how does the stroma build organic molecules from CO2?

Back 19

by using energy from ATP coupled with reduction via NADPH

Front 20

in the thylakoid membrane, photosynthetic pigments are clustered together to form ______

Back 20

photosystems

Front 21

what do photosystems do?

Back 21

act as large antennas, gatering the light energy harvested by many individual pigment molecules

Front 22

where do light-dependent reactions occur?

Back 22

in the thykaloid membrane

Front 23

where do light-independent reactions occur?

Back 23

thykaloids

Front 24

what is the general equation of photosynthesis

Back 24

CO2 + H2A + light energy ---> (CH2O) + H2O + 2A

Front 25

what does the H2A stand for in plants?

Back 25

water

Front 26

what does the H2A stand for in purple sulfur bacteria

Back 26

hydrogen sulfide

Front 27

Where does the product, A, come from?

Back 27

the splitting of H2A

Front 28

the O2 produced during the green plant photosynthesis results from what?

Back 28

splitting water

Front 29

in algae and green plants, the carbohydrate typically produced from photosynthesis is...?

Back 29

glucose

Front 30

light exhibits nature of both ____ and ____.

Back 30

wave and particle

Front 31

what two pigments are used in green plant photosynthesis?

Back 31

chlorophyll and carotenoids

Front 32

two kinds of chlorophylls in plants

Back 32

chlorophyll a and chlorophyll b

Front 33

what light do the two chlorophylls absorb?

Back 33

violet blue and red

Front 34

chlorophyll a and b never absorb photons with wavelengths between...?

Back 34

500 and 600 nm

Front 35

the main photosynthetic pigment in plants

Back 35

chlorophyl a

Front 36

the only pigment that can act directly to convert light energy into chemical energy

Back 36

chlorophyll a

Front 37

secondary light-absorbing pigment

Back 37

accesory pigment

Front 38

complements the light absorption of chlorophyll a

Back 38

chlorophyll b

Front 39

relative effectiveness of different wavelengths of light in promoting photosynthesis

Back 39

action spectrum

Front 40

what type of light do carotenoids absorb and reflect

Back 40

absorb blue and green and reflect orange and yellow

Front 41

the dotted line is

Back 41

chlorophyll b

Front 42

in chloroplasts and all but one class of photosynthetic prokaryotes, what captures light?

Back 42

photosystems

Front 43

what two closely linked components make up a photosystem?

Back 43

an atenna complex and a reaction center

Front 44

what composes an antenna complex?

Back 44

hundreds of pigment molecules

Front 45

what do the pigment molecules in the antenna complex of photosystems do?

Back 45

collect photons and feed the captured light energy to the reaction center

Front 46

what composes the reactions center of a photosystem?

Back 46

one or more chorophyll a molecules in a matrix of protein

Front 47

what do the chlorophyll a molecules in the reaction complex of a photosystem do?

Back 47

pass excited electrons out of the photosystem

Front 48

wat is the antenna complex also called?

Back 48

light-harvesting complex

Front 49

a photosystem consists of an antenna complex for _____ _______ and a reaction center where _____ ______ occur.

Back 49

light harvesting; photochemical reactions

Front 50

what is key to converting light into chemical energy?

Back 50

passing excited electrons to an acceptor, transferring energy away from the chlorophylls

Front 51

why are the ligh-dependent reactions also called the thylakoid reactions?

Back 51

because the thylakoid membrane is highly organized and contains the structures involved in the light-dependent reactions

Front 52

four stages of thylakoid/light-dependent reactions

Back 52

primary photoevent, charge separation, electron transport, and chemiosmosis

Front 53

a photon of light is captured by a pigment, which excites an electron within the pigment

Back 53

primary photoevent

Front 54

excitation energy is transferred to the reaction center, which transfers and energetic electron to an acceptor molecule, initiating electron transport

Back 54

charge separation

Front 55

excited electrons are shuttled along a carrier molecule, and several of them transport photons across the membrane, creating a proton gradient; eventually they are used to reduce NADPH

Back 55

electron transport

Front 56

the protons that have accumulated on one side of the membrane now flow back across the membrane through ATP synthase channels

Back 56

chemiosmosis

Front 57

process in which ATP is generated via electron transport in a photosystem, and those electrons then return to the reaction center

Back 57

cyclic phosphorylation

Front 58

name of the reaction center pigment in photosystem II in which peak absorption occurs

Back 58

P680

Front 59

The noncyclic transfer of electrons that occurs in the two linked photosystems of plants produces _____, which plays a key role in the biosynthesis of carbohydrates

Back 59

NADPH

Front 60

which photosystem has an absorption peak at 700 nm?

Back 60

photosystem I

Front 61

which photosystem can produce an oxidation potential high enough to oxidize water?

Back 61

photosystem II

Front 62

is the interaction between photosystems one and two cyclic or noncyclic?

Back 62

noncyclic

Front 63

protons are pumped along the thylakoid membrane in the ___ ____ stage of light-dependent reactions

Back 63

electron transport

Front 64

during the fourth stage of light-dependent reactions, called the ____ stage, protons flow back across the photosynthetic membrane and in the process _____ is synthesized

Back 64

chemiosmosis; ATP

Front 65

which organism has only one photosystem?

Back 65

anoxygenic bacteria

Front 66

can anoxygenic bacteria oxydize water?

Back 66

no

Front 67

how do plants benefit from having two linked photosystems?

Back 67

it allows them to use electrons from water to reduce NADP+

Front 68

the key difference between PSI and PSII are

Back 68

how their pigments receive electrons and how they transfer those electrons

Front 69

which photosystem's main function is to generate high-energy electrons for ATP?

Back 69

photosystem II

Front 70

two stage process in which photosystems II and I are used in series to produce both ATP and NADPH

Back 70

noncyclic photophosphorylation

Front 71

primary electron acceptor for the elctrons leaving photosystem II

Back 71

quinone molecule

Front 72

reduced quinone that passes the excited electron pair to a proton pump

Back 72

plastoquinone

Front 73

proton pump imbedded in the thylakoid membrane that pumps protons into the thylakoid space

Back 73

b6-f complex

Front 74

copper containing protein that carries the electrons to photosystem I

Back 74

plastocyanin

Front 75

energy is fed into the reaction system of photosystem I by an ____ _____ consisting of _____ __ and accessory pigment molecules

Back 75

antenna complex; chlorophyll a

Front 76

electrons are passed from the reaction center of photosystem I to an iron-sulfur protein called ________

Back 76

ferredoxin

Front 77

what does photosystem I not rely on the phtosyste one does?

Back 77

quinone

Front 78

electrons are then donated from ferredoxin to ____ to make ______

Back 78

NADP+; NADPH

Front 79

the reaction NADP+ ---> NADPH is catalyzed by _____

Back 79

NADP reductase

Front 80

the chloroplast has _____ ______ enzymes that allow protons to cross back out into the stroma

Back 80

ATP synthase

Front 81

As protons pass through ATP synthase channels, ____ is phosphorylated into ____ and released into the stroma.

Back 81

APD; ATP

Front 82

the stroma contains the enzymes that catalyze the reactions of ____ ______, the ___ ____ reactions

Back 82

carbon fixation, calvin cycle

Front 83

similar to ATP synthesis in mitochondria, ATP synthesis in chloroplasts is achieved by a(n) _______ mechanism called ________

Back 83

chemiosmosis; photophosphorylation

Front 84

what are used by green plants to absorb light energy?

Back 84

chlorophyll a and b

Front 85

during photosynthesis, light energy is converted into ___ energy

Back 85

chemical

Front 86

what are the products of photosynthesis?

Back 86

oxygen and carbohydrates

Front 87

where do the light reactions of photosynthesis occur? the calvin cycle?

Back 87

thylakoid membrane; stroma

Front 88

the oxygen produced by plants from photosynthesis comes from the splitting of ______

Back 88

H2O

Front 89

what occurs during the charge separation stage of thylakoid reactions?

Back 89

an excited electron is transferred out of the photosystem

Front 90

what occurs during the primary photo event?

Back 90

a photon is captured by a pigment in the photosystem

Front 91

what is the final acceptor in the electron transort stage

Back 91

NADP

Front 92

what wavelengths of light are preferentially absorbed by chlorophyll molecules?

Back 92

violet-blue and red

Front 93

what are the parts of a chlorophyll molecule?

Back 93

a hydrocarbon tail and a poryphyrin ring

Front 94

how is an H+ electrochemical gradient established and maintained during photosynthesis

Back 94

the formation of NADPH, the movement of electrons from PSII to PSI, and the splitting of water

Front 95

in chloroplasts, several dozen of ____ help comprise a light harvesting complex

Back 95

pigments

Front 96

______ absorb energy that is not efficiently absorbed by chlorophylls, and they scavenge ____ ____

Back 96

carotenoids; free radicals

Front 97

in anoxygenic bacteria, what is the ultimate fate of an electron after it leaves the photosystem?

Back 97

it returns to the reaction center after it passes through the electron transport chain

Front 98

what utilizes hydrogen sulfide and accumulate sulfur in their cells?

Back 98

purple bacteria