Exam 2 - Photosynthesis

Question 1

equation for photosynthesis

Answer 1

CO2 + water + sunlight = glucose + oxygen

Question 2

Light reactions

Answer 2

conversion of sunlight into ATP and NADPH

Question 3

Dark reactions

Answer 3

formation of carbohydrates

Question 4

composition of chloroplasts

Answer 4

outer membrane
intermembrane space
inner membrane
stroma (matrix)
thylakoids

Question 5

what are grana

Answer 5

stacks of thylakoids

Question 6

chlorophyll a and b

Answer 6

reflect green and yellow

absorb red and blue

sunlight excites the pigments and water is split

Question 7

where do the light reactions occur

Answer 7

in the thylakoids

Question 8

where do the dark reactions occur

Answer 8

in the stroma

Question 9

resonance energy transfer

Answer 9

the transfer of e- to pigments

Question 10

photoexcitation

Answer 10

e- energized from the ground state to excited state

Question 11

flow of electrons in light reactions

Answer 11

1. PS II
2. Plastoquinones
3. cytochrome complex
4. plastocyanin
5. PS I
6. Ferredoxin/Ferredoxin reductase

Question 12

what is the final electron acceptor for photosynthesis

Answer 12

NADP+

Question 13

photophosphorylation

Answer 13

H+ gradient used to synthesize ATP using ATP synthase

Question 14

where does the calvin cycle occur

Answer 14

in the stroma of the chloroplast

Question 15

what is required for the calvin cycle

Answer 15

ATP and CO2

Question 16

how does the calvin cycle begin

Answer 16

with 3 ribulose 1,5 bisphosphates and 3 CO2 molecules being converted to 6 molecules of 3-phosphoglycerate

Question 17

how many molecules of G3P are made and how many go in each direction

Answer 17

6. 5 remain in the cycle, 1 leaves to make the carbohydrate

Question 18

which carbohydrate is G3P converted into

Answer 18

if it leaves the chloroplast = sucrose

if it stays in chloroplast = starch

Question 19

rubisco

Answer 19

most abundant enzyme on Earth

can act as a carboxylase or a oxygenase

Question 20

what happens if rubisco makes phosphoglycolate

Answer 20

it has no use in the calvin cycle, so it enters the glycolate pathway

Question 21

what is the glycolate pathway

Answer 21

it returns most of the carbons in phosphoglycolate to 3-phosphoglycerate and the other carbons as CO2 (photorespiration)

without this, phosphoglycolate would become toxic and ribulose 1,5 bisphosphate would not be generated

Question 22

what is the solution to increased Rubisco oxygenase function

Answer 22

confine rubisco to cells that contain high [CO2]

Question 23

what are C3 plants

Answer 23

plants that have the calvin cycle in mesophyll cells for increased CO2 (no issues)

Question 24

what are C4 plants

Answer 24

plants that have the calvin cycle in bundle sheath cells (can create issues)

Question 25

what is the Hatch-Slack cycle

Answer 25

a cycle that allows the build up of CO2 in the form of malate, so that cells have rubisco acting correctly as a carboxylase

Question 26

what is the difference between CAM plants and C4 plants

Answer 26

both utilize the Hatch-Slack cycle

CAM plants segregate CO2 by time (they only open stomata at night, so the Hatch-Slack cycle has to run during the day)

C4 plants segregate CO2 by space