chapter10-photosynthesis

Question 1

What are the inputs and outputs of light reactions?

Answer 1

inputs: light, water, ADP, NADP+
outputs: oxygen, ATP, NADPH

P680 is the molecule that oxidizes water.

Question 2

What are the inputs and outputs of the Calvin cycle?

Answer 2

inputs: ATP, NADPH, CO2
outputs: G3P, ADP, NADP+

Question 3

What is the formula for photosynthesis?

Answer 3

nCO2 + nH2O + Photons –> (CH2O)_n + nO2

in the case of glucose production
6CO2 + 6H2O + Photons –> 1C6H12O6 (glucose) + 6O2

Question 4

Define fixed carbon

Answer 4

carbon from carbon dioxide that can be incorporated into organic molecules; process known as carbon fixation. The carbon in organic molecules is known as fixed carbon.

Question 5

What is the process by which carbon can be incorporated into organic molecules from carbon dioxide?

Answer 5

carbon fixation

Question 6

What are photoautotrophs (or autotrophs)?

Answer 6

organisms that produce their own food. they fix carbon using light energy.

Question 7

What are heterotrophs?

Answer 7

organisms that cannot convert carbon dioxide into fixed carbon. they obtain fixed carbon from autotrophs.

Question 8

What is the mesophyll?

Answer 8

the middle layer of a leaf tissue that is the primary site of photosynthesis.

Question 9

What is the stomata (plural; stoma = singular)?

Answer 9

Found on the surface of leaves in most plants. They let carbon dioxide diffuse into the mesophyll, and oxygen diffuse out.

Question 10

What is the chloroplast?

Answer 10

an organelle in a cell where photosynthesis occurs.

Question 11

What is the chlorophyll?

Answer 11

a green colored pigment that is contained in the membrane of each thylakoid. their purpose is to absorb light.

Question 12

What is a Thylakoid?

Answer 12

a disk like structure in the chloroplast.

Question 13

What is the thylakoid space (or lumen)?

Answer 13

the space inside a thylakoid (or liquid)

Question 14

What is the grana (plural; granum = singular)?

Answer 14

stacks of thylakoids.

Question 15

What is the formula for light dependent reactions?

Answer 15

Photons + H2O –> ATP + NADPH + O2

Question 16

What is a photosystem?

Answer 16

large complex of proteins and pigments (light absorbing molecule) that are optimized to harvest light.

They are found (or embedded) in the thylakoid membrane.

Question 17

What does PS2 do?

Answer 17

molecule in the center is P680. It oxidizes oxygen from H2O and produces O2 gas.

Question 18

What does PS1 do?

Answer 18

molecule in the center is P700. the excited molecule eventually facilitates the reduction of NADP+ to NADPH.

Question 19

What is the final electron acceptor in photosynthesis?

Answer 19

NADP+
It accepts the electron a little after PS1.

Question 20

What is the name of the enzyme that brings CO2 into the cell for the Calvin cycle?

Answer 20

Rubisco

Question 21

What is the name of the molecule that bonds with CO2 to make a 6-carbon in the Calvin cycle?

Answer 21

RuBP
Ribulose 1, 5-bisphosphate

it then immediately splits into 2 3-carbon molecules and proceeds to use ATP and NADPH to make G3P.

Question 22

Accounting for photosynthesis.
How much ATP was used total per 1 G3P?
How much NADPH was used total per 1 G3P?

Answer 22

9 ATP (6 for synthesis of G3P, and 3 for regeneration of RuBP)
6 NADPH

Question 23

What are C_3 plants?

Answer 23

first organic compound produced is 3-PGA (when rubisco adds CO2 to RuBP).

this is the first step when the 6-carbon is broken down into two 3-carbon

this is the most common type of photosynthesis.
(includes: soybeans, oats, wheat, rice)

this method is of photosynthesis is not very good for DRY environments.

Question 24

What are C_4 plants?

Answer 24

still continues to perform photosynthesis but it needs to fix it’s carbon dioxide (using PEP reaction; 3-carbon) for the Calvin cycle.

carbon fixation and Calvin cycle occurs in different cells.

Question 25

What are CAM plants?

Answer 25

(pineapples, aloe) open their stomata and admitting CO2 only at night. they store the inputs needed for Calvin cycle in Vacuole. Thus they can perform photosynthesis during the day when the stomata are closed. succulent plants (cacti) carbon fixation and Calvin cycle occurs in the same cell but at DIFFERENT TIMES.

Question 26

What is the purpose of C4 and CAM plants?

Answer 26

to maintain photosynthesis and conserve water during hot dry days.

Question 27

Where does H+ accumulate in photosynthesis?

Answer 27

in the thylakoid space (or lumen)

Question 28

Where is the location of the Calvin cycle?

Answer 28

the stroma

Question 29

Where is the location of the light reactions?

Answer 29

in the thylakoid disks

Question 30

In C3 plants, the conservation of water promotes _____ ?

Answer 30

photorespiration Conserving water simultaneously reduces the amount of carbon dioxide available to the plant.

Question 31

In C4 and CAM plants carbon dioxide is fixed in the _____ of mesophyll cells.

Answer 31

cytoplasm

Question 32

C4 plants differ from C3 and CAM plants in that C4 plants _____.

Answer 32

transfer fixed carbon dioxide to cells in which the Calvin cycle occurs In C3 and CAM plants carbon dioxide fixation and the Calvin cycle occur in the same cells.

Question 33

What is the relationship between photosynthesis and cellular respiration?

Answer 33

Photosynthesis stores energy in complex organic molecules; cellular respiration releases energy from complex organic molecules.

Question 34

Why are plants classified as producers?

Answer 34

they fix inorganic carbon into organic molecules.

Question 35

The light reactions of photosynthesis use _____ and produce _____.

Answer 35

water ... NADPH

Question 36

What is the flow of electrons in photosynthesis?

Answer 36

H2O → NADPH → Calvin cycle

Question 37

Where is the proton pump in photosynthesis?

Answer 37

between PS2 and PS1

Question 38

In which cellular structure are the enzymes of the Calvin cycle localized?

Answer 38

stroma of the chloroplast

Question 39

How is photosynthesis similar in C4 plants and CAM plants?

Answer 39

In both cases, rubisco is not used to fix carbon initially.

Question 40

What is the stroma?

Answer 40

The stroma is the liquid that surrounds the thylakoids