Light Dependent Reaction

Question 1

• requires sunlight
• occurs in thylakoid membrane
• involves two photosystems and an electron transport chain

Answer 1

light-dependent reaction

Question 2

where does LDR occur?

Answer 2

thylakoid membrane

Question 3

Large complexes of proteins and pigments (light absorbing molecules) that are optimized to harvest light.

Answer 3

photosystem

Question 4

Reaction-center complex and Light- harvesting complex

Answer 4

photosystem

Question 5

• Special pair of chl a molecules
• Primary electron acceptor

Answer 5

Reaction-center complex

Question 6

• With various pigment molecules (~300-400)

Answer 6

Light- harvesting complex

Question 7

goal of photosystem

Answer 7

create ATP and NADPH by energizing the two photosystems

Question 8

PS1 special pair of chl a molecules

Answer 8

P700

Question 9

PS2 special pair of chl a molecules

Answer 9

P680

Question 10

sequence of LDR

Answer 10

light absorption in PS2, atp synthesis, light absorption in PS1, nadph formation

Question 11

movement of energy from one pigment to another until it reachers the special pair of chlorophyll a molecule

Answer 11

resonance energy transfer

Question 12

primary electron acceptor of PS2

Answer 12

pheophytin

Question 13

One of the molecule’s electrons is elevated to an orbital where it has more potential energy, which
makes it _____.

Answer 13

excited

Question 14

The electron will be passed on
through the first leg of the photosynthetic electron
transport chain in a series of
_______

Answer 14

redox reaction

Question 15

to fill the donated electron of PS 2

Answer 15

photolysis

Question 16

where does photolysis happen?

Answer 16

thylakoid lumen

Question 17

photolysis

Answer 17

An enzyme catalyzes water to split into:
* 2 electrons
* 2 Hydrogen ions (H+)
* 1 oxygen atom

Question 18

in photolysis, hydrogen ions

Answer 18

stay in the thlyakoid lumen

Question 19

in photolysis, oxygen atom

Answer 19

Forms O2 and exits via stomata

Question 20

From the primary electron acceptor, the electron is now transferred to PS I via the

Answer 20

electron transport chain

Question 21

electron transport chain

Answer 21

o Cytochrome complex (Cyt)
o Plastoquinone (Pq)
o Protein- plastocyanin (Pc)

Question 22

ETC releases

Answer 22

free energy

Question 23

PS1 primary electron acceptor

Answer 23

A0

Question 24

PS1

Electrons are passed in a series of redox reactions down to the ETC through the protein

Answer 24

ferredoxin (Fd)

Question 25

_______ catalyzes the transfer of electrons from Fd to NADP+

Answer 25

NADP+ reductase

Question 26

_____ electrons are needed to reduce NADP+ to NADPH

Answer 26

two

Question 27

The movement of hydrogen ions down their electrochemical gradient through the transmembrane enzyme ATP synthase.

Answer 27

chemiosmosis

Question 28

Electrons loop back to the first part of the electron transport chain, repeatedly cycling through PSI instead of ending up in NADPH.

Answer 28

Cyclic Photophosphorylation

Question 29

Cyclic Photophosphorylation

The electrons cycle back from ____ to the ______, then via a _____ to a
P700 chlorophyll in the PS I
reaction-center complex.

Answer 29

ferredoxin (Fd), cytochrome complex, plastocyanin molecule (Pc)

Question 30

No release of oxygen or production of NADPH but generates ATP

Answer 30

Cyclic Photophosphorylation

Question 31

o Single photosystems such as purple and green sulfur bacteria
o Mutations
o when too little NADP is available to accept electrons
o High ATP needs
o For photoprotection

Answer 31

Cyclic Photophosphorylation