Photosynthesis I

Question 1

Photosynthesis describes the process by which photosynthetic organisms ______, synthesize organic compounds from ______ raw materials using ____

Answer 1

photoautotrophs; inorganic; light

Question 2

Photosynthesis is the means for ____ to enter into the global ecosystem, and it alone is the essential biological process by which solar energy is transformed into _____ for all forms of life on earth.

Answer 2

solar energy; metabollic form of energy

Question 3

Light has characteristics of both a:

Answer 3

particle and a wave

Question 4

Is characterized by wavelength

Answer 4

Wave

Question 5

Is also a particle, which we call a photon

Answer 5

Light

Question 6

Each photon contains an amount of energy that is called a

Answer 6

Quantum (plural quanta)

Question 7

Pigments (3)

Answer 7

1. Xanthophyll - yellow
2. Phaeophytin a - gray-brown
3. Phaeophytin b - yellow-brown

Question 8

All _____ radiation is light, but we can only see a small portion of this radiation- the portion we call _____

Answer 8

electromagnetic; visible light

Question 9

The reason that there are so many pigments is …

Answer 9

is that each absorbs light more efficiently in a different part of the electromagnetic spectrum

Question 10

As objects grow hotter, they radiate energy dominated by

Answer 10

shorter wavelengths

Question 11

For the 2 photosystems, chlorophyll ___ exist to assist the _______ by absorbing specific _________.

Answer 11

a&b; photosynthetic process; specific spectra of light energy

Question 12

Chlorophyll-a absorbs the ______

Answer 12

• violet blue-blue wavelengths of light
• orange to far-red

Question 13

violet blue-blue wavelengths of light (nm)?

Answer 13

390-450 nm
peak: 420 nm

Question 14

orange to far-red nm

Answer 14

600-700nm
peak: 680 nm

Question 15

Chlorophyll b absorbs

Answer 15

violet blue to green blue light
and yellow to red light

Question 16

violet blue to green blue light nm

Answer 16

390-500 nm
peak 480nm

Question 17

yellow to red light

Answer 17

600nm - 680nm
peak: 630 nm

Question 18

plants still use the green and yellow spectra as there exist photopigments that turn green or yellow photons into blue and red photons through

Answer 18

excitation and emittance reactions

Question 19

Blue light radiation wavelengths

Answer 19

400 and 500 nm

Question 20

less efficient green or red photons , some of the energy is essentially lost compared to photosynthetic photons

Answer 20

Blue light

Question 21

is a phytochemical that absorbs blue spectrum and initiates phototropism + sets a plants circadian rhythm

Answer 21

Cytochrome

Question 22

in combination with phytochrome and photoperiod

Answer 22

circadian rhythm

Question 23

allows energy to move from the site of initial absorbance to the reaction center

Answer 23

Resonance Energy Transfer

Question 24

Fastest chemical reactions

Answer 24

Photochemical reactions of photosynthesis

Question 25

Excited chlorophyll can re-emit a photon and thereby return to its ground state- a process known as

Answer 25

Fluorescence

Question 26

Large protein assemblies that enable Cynobacteria (blue-green algae) and red algae to harvest the green and yellow light that penetrates to their niche

Answer 26

Phycobilisomes

Question 27

Red Algae under the sea

Answer 27

Rhodophyta

Question 28

Pigments are chemically _____ which have a ____ at the center.

Answer 28

porphyrin molecules; metal ion

Question 29

The metal ion in hemoglobin is ___ in chlorophyll, it is ____

Answer 29

iron; magnesium

Question 30

Funnels energy into reaction centers

Answer 30

Accessory Pigments

Question 31

Photosystem I and ATP synthase are located in ____; Photosystem II are located in ____

Answer 31

PSI - unstacked regions PSII - stacked regions

Question 32

Thylakoid membranes regions:

Answer 32

1. Stacked - Apressed 2. Unstacked - nonappressed

Question 33

The most active photosynthetic tissue in higher plants is the

Answer 33

mesophyll of leaves

Question 34

Electron Transport Chain

Answer 34

1. Photons hits chloropyll 2. Photoionization 3. Electrons Transfer 4. Photolysis of Water

Question 35

Electrons are excited

Answer 35

Photoionization

Question 36

The Electron transfer in ETC is via ____ to _____

Answer 36

via protein complex (electron carrier) to PSII

Question 37

In Photolysis of Water, Light hits water and releasing ___ as byproduct and fill in ____ of the _____.

Answer 37

oxygen; electrons of the oxidised P680

Question 38

reaction centers

Answer 38

P680 (PSII) P700 (PSI)

Question 39

(Light reaction) The ultimate source of the electrons is the _____, which is photolyzed to release ___, ___, ___, while the final destination is ____, which is thereby reduced to____

Answer 39

water molecule electrons, protons and O2 NADP, which is thereby reduced to NADPH

Question 40

Photosystem II water oxidation

Answer 40

Oxygen-evolving complex

Question 41

What are free-radicals

Answer 41

Free radicals are highly reactive molecules with an unpaired electron that can damage cells but also play important roles in metabolism.

Question 42

Is a dimer having two plastoquinone binding sites facing each other- Catalyze the transfer of electron

Answer 42

Cytochrome b6f

Question 43

Light Reactions in Photosynthesis (PSI)

Answer 43

Photons hits PSI Electron Transfer Reduction of NADP

Question 44

The electron transfer in PSI occurs through the activity of an intermediate enzyme-

Answer 44

ferredoxin-NADP reductase (FNR)

Question 45

A multiprotein complex containing at least 11 polypeptide chains. - Key players in the process of oxygenic photosynthesis.

Answer 45

Photosystem I

Question 46

PSI transfers electrons from the ___ across the photosynthetic membrane to the _____

Answer 46

1. lumenal electron carriers, plastocynanin/ cytochrome b6 2. stromal cytosolic electron carriers ferredoxin

Question 47

PSI (Production of NADPH)

Answer 47

Cyclic Electron Transport

Question 47

Proton gradient between the lumen of thylakoid and stroma is the result of

Answer 47

1. Photolysis of water 2. Transport of H+ from stroma to the lumen 3. Utilization of H+ for reduction of NADP+ to NADPH

Question 47

- PSI and ATP synthase are present in the outer membrane of the stacked lamellae and are exposed to stroma. This phenomenon is called

Answer 47

Lateral heterogeneity

Question 47

The process of pumping of photons across thylakoid membrane, creating H+ gradient which leads to ATP generation

Answer 47

Cyclic Photophosphorylation

Question 48

Lateral heterogeneity indicates that the photosystems which participate in transferring of electrons from H2O to NADP+ in the photosynthetic electron transport chain are

Answer 48

Spatially separated

Question 49

Spatial separation of photosystems prevents

Answer 49

Prevents light energy from being preferably transferred to PSI, and PSII also functions effectively