Photosynthesis

Question 1

Photosynthesis

Answer 1

The conversion of light energy to chemical energy

Question 2

Autotrophs

Answer 2

Organisms that produce their own food from substances in their surroundings ex. plants

Question 3

Heterotrophs

Answer 3

Organisms unable to make their own food so they live off of other organisms

Question 4

Photosynthesis first evolved in a

Answer 4

Prokaryotic organism

Question 5

Where is the primary location for photosynthesis?

Answer 5

1.Leaves
2. Stomata: pores in the leaves that allow CO2 and O2 out

Question 6

What is surrounded by a double membrane?

Answer 6

The chloroplast

Question 7

Stroma

Answer 7

Aqueous internal fluids, where the calvin cycle begins

Question 8

Thylakoids

Answer 8

Form stacks known as grana, within the thylakoid is where light reactions take place

Question 9

Chlorophyll

Answer 9

Green pigment in thylakoid membranes

Question 10

Oxidation

Answer 10

Loss of e-

Question 11

Reduction

Answer 11

Gain of e-

Question 12

Redox reaction

Answer 12

Reaction involving complete or partial transfer of one or more electrons from one reactant to another

Question 13

Photosynthesis formula

Answer 13

(see notes)

Question 14

Photosystems

Answer 14

1. Where light comes in
2. Reactions centers- complex of proteins associated with chlorophyll and an electron acceptor

Question 15

How is ATP formed during light reactions?

Answer 15

The “fall” of electrons from their excited state back to their ground state from PSII to PSI provides energy to form ATP

Question 16

Why is the splitting of water important in the light reactions?

Answer 16

Creates the proton gradient, uses the H+ to turn ATP synthase

Question 17

What is solar energy temporarily stored in?

Answer 17

NADPH (electron carrier) and ATP

Question 18

EXPLAIN light reactions in the thylakoids

Answer 18

(see notes)

Question 19

Inputs of light reactions

Answer 19

1. H20
2. ADP
3. NADP+ (ben w/o the ball)

Question 20

Outputs of light reactions

Answer 20

1. 02
2. ATP
3. NADPH (ben w/ball, electron carrier)

Question 21

What is released in the light reactions as a byproduct?

Answer 21

O2

Question 22

What does the calvin cycle do to reduce CO2?

Answer 22

Uses ATP and NADPH to reduce CO2 to sugar (G3P)

Question 23

How many times must the cycle occur to create a net gain of 1 G3P molecule?

Answer 23

3 times

Question 24

Three phases of the calvin cycle

Answer 24

1. Carbon fixation
2. Reduction
3. Regeneration of RuBP

Question 25

Carbon fixation

Answer 25

1. CO2 incorporated into the cycle one at a time
2. Each CO2 molecule attaches to a molecule of RuBP, which has five carbons
3. RuBP forms 3-phosphoglycerate

Question 26

Reduction

Answer 26

1. Each molecule of 3-phosphoglycerate is phosphorylated (broken down to two phosphates for energy) by ATP
2. NADPH oxidized to NADP+ and then reduced to G3P
3. 6 molecules of G3P created but only one considered a net gain

Question 27

Regeneration of RuBP

Answer 27

1. 5G3P molecules used to regenerate 3 molecules of RuBP, uses energy from breaking 3 ATP into ADP
2. Cycle now ready to take in CO2 again

Question 28

Inputs of Calvin Cycle

Answer 28

1. 3CO2
2. 9ATP
3. 6NADPH

Question 29

Outputs of Calvin Cycle

Answer 29

1. 1G3P
2. 9ADP
3. 6NADP+

Question 30

Photorespiration

Answer 30

On very hot days plants close their stomata to stop water loss
-Rubisco binds to O2 and uses ATP
-Process produces CO2
-No sugar produced, bad for plant

Question 31

C4 Plants

Answer 31

-Process of photosynthesis happens at different times
-Stomata partially closed to conserve water
-Mesophyll cells fix CO2 into a 4-carbon molecule
-Releases CO2 to be used in the Calvin Cycle
-Transferred to bundle sheath cells
-Ex. Corn

Question 32

CAM plants

Answer 32

-Open stomata at night and closed during the day
-CO2 is incorporated into organic acids and stored in vacuoles
-During the day, light reactions occur and CO2 is released from the organic acids and incorporated into the Calvin cycle
-Ex. Pineapples, succulents, cacti