Ch.10 Photosynthesis

Question 1

photosynthesis

Answer 1

process that converts solar energy into chemical energy and occurs in plants, algae, certain other protists, and some prokaryotes

Question 2

autotrophs

Answer 2

produce organic molecules from CO2 and other inorganic molecules

Question 3

photoautotrophs
(almost all plants)

Answer 3

use the energy of sunlight to make organic molecules from H2O and CO2

Question 4

heterotrophs

Answer 4

consume organic material from other organisms

Question 5

where does photosynthesis occur

Answer 5

mostly in the leaves

Question 6

stomata

Answer 6

microscopic pores where CO2 enters and O2 exits the leaf

Question 7

mesophyll

Answer 7

interior tissue of the cell

Question 8

thylakoids

Answer 8

connected sacs in the chloroplast

Question 9

grana

Answer 9

stacks of thylakoids

Question 10

where is chlorophyll found

Answer 10

in thylakoid membrane

Question 11

stroma

Answer 11

contained in chloroplasts, dense fluid

Question 12

what does chlorophyll do?

Answer 12

absorbs light energy in order to drive the synthesis of organic molecules in the chloroplast

Question 13

photosynthesis is a redox reaction, what is oxidized/reduced?

Answer 13

H2O is oxidized
CO2 is reduced

Question 14

two parts of photosynthesis?

Answer 14

• light reactions (“photo”)
• Calvin Cycle (“synthesis”)

Question 15

what happens during light reaction in the thylakoids?

Answer 15

• H2O splits
• O2 released
• NADP+ — > NADPH
• ADP —-> ATP via phosphorylation

Question 16

wavelength

Answer 16

distance between crests of waves

Question 17

electromagnetic spectrum

Answer 17

entire range of electromagnetic energy or radiation

Question 18

visible light

Answer 18

wavelengths that produce colors we can see

Question 19

photons

Answer 19

discrete particles that makeup light

Question 20

spectrophotometer

Answer 20

measure a pigment’s ability to absorb various wavelengths

Question 21

absorption spectrum

Answer 21

graph plotting a pigment’s light absorption versus wavelength

Question 22

chlorophyll a

Answer 22

suggests violet-blue and red light work best for photsynthesis

Question 23

carotenoids

Answer 23

absorb excessive light that would damage chlorophyll

Question 24

what happens when a pigment absorbs light

Answer 24

it goes from a stable ground state to an excited state

Question 25

fluorescence

Answer 25

afterglow produced when electrons fall back to ground state and some of their photons are given off

Question 26

photosystem

Answer 26

reaction-center complex surrounded by light-harvesting molecules

Question 27

reaction-center complex

Answer 27

protein complex

Question 28

light-harvesting complexes

Answer 28

pigment molecules bound to proteins that funnel the energy of photons to the reaction center

Question 29

photosystem II

Answer 29

functions first and is best at absorbing wavelength of 680nm

Question 30

photosystem I

Answer 30

best at absorbing wavelength of 700nm

Question 31

P680

Answer 31

reaction-center chlorophyll of a of PS II

Question 32

P700

Answer 32

reaction-center chlorophyll a of PS I

Question 33

chemiosmosis

Answer 33

• mitochondria generate ATP from food
• chloroplasts transform light energy into chemical energy of ATP

Question 34

chemiosmosis in mitohondria

Answer 34

protons are pumped to the intermembrane space and drive ATP synthesis as they diffuse back into the mitochondrial matrix

Question 35

chemiosmosis in chloroplasts

Answer 35

protons are pumped into the thylakoid space and drive ATP synthesis as they diffuse back into the stroma

Question 36

Calvin Cycle does what?

Answer 36

uses ATP and NADPH to convert CO2 to sugar

Question 37

how does the Calvin Cycle work?

Answer 37

carbon enters the cycle as CO2 and leaves as sugar (glyceraldehyde-3-phosphate, G3P)

Question 38

how many cycles for 1 G3P?

Answer 38

3

Question 39

phases of the Calvin Cycle?

Answer 39

• carbon fixation
• reduction
• regeneration of the CO2 acceptor (RuBP)

Question 40

what catalyzes carbon fixation?

Answer 40

rubisco

Question 41

what happens to plants on hot days?

Answer 41

stomata closes to conserve H2O causing O2 buildup, cutoff CO2 access and reducing photosynthesis

Question 42

photorespiration

Answer 42

wasteful process in plants which is favored by the condition brought about by a hot summer day

Question 43

cyclic electron flow

Answer 43

uses only photosystem I and produces ATP satisfying higher demand in Calvin Cycle, no NADPH

Question 44

C4 plants

Answer 44

minimize cost of photorespiration by incorporating CO2 into four-carbon compounds in mesophyll cells

Question 45

crassulacean acid metabolism (CAM)

Answer 45

used by some plants, this is a form of carbon fixation in which the stomate opens at night taking in CO2, and closes during the day to release CO2 from organic acids and use it in the Calvin Cycle