Photosynthesis

Question 1

Photosynthesis

Answer 1

Energy for all life on Earth ultimately comes from sunlight captured by photosynthesis
One of most significant metabolic processes on Earth

Question 2

Photosynthesis equation

Answer 2

6CO2 + 12H2O + light energy=C6H12O6 + 6H2O + 6O2

Question 3

Oxygenic photosynthesis is carried out by

Answer 3

Cyanobacteria
7 groups of algae
All land plants (have chloroplasts)

Question 4

Anoxygenic photosynthesis does not produce O2 and is carried out by:

Answer 4

At least 5 different groups of BacteriaAnoxygenic phototrophy is better term especially if energy gained from light is not used to fix CO2

Question 5

Light-dependent” reactions where

Answer 5

Thylakoid membrane of the chloroplast

Question 6

Light dependent reactions are called what

Answer 6

Photosynthetic electron-transfer reactions

Question 7

“Light-independent” reactions.. were

Answer 7

stroma called carbon fixation

Question 8

“Light-independent” reactions are called what

Answer 8

Carbon-fixation reactions in stroma

Question 9

What do light DEPENDENT reactions do?

Answer 9

Capture energy from sunlight in Pigments
Use light energy to make ATP
reduce NADP+ to NADPH in thylakoid

Question 10

Light Independent reactions do>

Answer 10

Use ATP and NADPH to power synthesis of organic molecules (monosaccharides) from CO2
in stroma

Question 11

Where are pigments found

Answer 11

thylakoid membrane

Question 12

2 types of pigments

Answer 12

Chlorophyll

Carotenoids (accessory)

Question 13

Chlorophyll

Answer 13

a (main) and b (accessory)

Similar structure, different absorption spectra

Question 14

Carotenoids (accessory)

Answer 14

Carotenes and xanthophylls

Example: b-carotene

Question 15

Pigments

Answer 15

alternating single and double bonds (i.e., way to transfer electrons/energy)

Question 16

2H2O oxidized =

Answer 16

produces O2 + 4H+ + 4e-

Question 17

Chlorophyll loses electron

Answer 17

(oxidized);

Question 18

chlorophyll gains electron

Answer 18

(reduced)

Question 19

Photosystem organization

Answer 19

Light harvesting complex

Question 20

Light harvesting complex

Answer 20

Capture photons (sunlight energy)
Excitation energy (not e-!) transferred from one pigment to another until reaches reaction center

Question 21

Reaction center

Answer 21

Contains chlorophyll special pair

Question 22

Reaction center Contains

Answer 22

chlorophyll special pair

Question 23

Chlorophyll special pair traps photon energy

Answer 23

passes excited electron to an acceptor

Question 24

Electron donor restores electron to chlorophyll special pair

Answer 24

Donor = water

Oxidation of water = release of O2

Question 25

4 steps of light dependent reaction

Answer 25

Primary photoevent & H2O oxidized
Charge separation
Electron transport
Chemiosmosis (ATP production)

Question 26

First step of light dependent reaction
photosystem II (comes before photosystem I)

Answer 26

Primary photoevent (Light energy (photons) absorbed)
H2O oxidized (replenishes lost electrons to reaction center; releases O2)

Question 27

second step of light dependent reaction

Answer 27

Charge separation (e- released to electron transport chain)

Question 28

third step of light dependent reaction

photosystem I

Answer 28

Electron transport (e- reduce NADP+ to NADPH)
H+ pumped from stroma into thylakoid space

Question 29

fourth step in light dependent reaction

Answer 29

Chemiosmosis (ATP production)

H+ leave thylakoid space (via ATP synthase) to stroma

Question 30

What steps occur in the thylakoid space

Answer 30

Steps 1-3

Question 31

How are the electrons replaced in photosystem I

Answer 31

Produced in photosystem II that occurs before it

Question 32

What produces ATP in the final step of light dependent reaction

Answer 32

ATP synthase using proton gradient

Question 33

How are the electrons replaced in photosystem II

Answer 33

By oxidation of water the O2