chapter 10 (part of biodiversity)

Question 1

how is energy in sunlight transformed to chemical energy

Answer 1

by converting C=0 bonds in CO2 to the C-C and C-H bonds of carb

Question 3

what is the main difference, when it comes to energy, in photosynthesis and cellular respiration?

Answer 3

photosynthesis is an energy demanding reaction and cellular respiration is an energy releasing reaction

Question 4

what are the two sets of reactions

Answer 4

• one that uses light to produce O2 from H2O
• one that converts CO2 into sugars

Question 5

calvin cycle

Answer 5

set of reactions that uses NADPH and ATP formed in the light capturing reactions to dive fixation of CO2

Question 6

what is going on in the light capturing reactions

Answer 6

• electrons promoted to a high energy state
• ignites chain of steps that ends with reduction of NADP+ to form NADPH

Question 7

what is some of the energy released from redox used for

Answer 7

produce ATP

Question 8

what do the light capturing reactions provide

Answer 8

high energy molecules that drive the Calvin cycle

Question 9

where does photosynthesis occur

Answer 9

chloroplasts

Question 10

what is the structure of a chloroplast

Answer 10

• enclosed by an outer membrane and inner membrane
• interior has flattened, membranous sac called thylakoids
• lumen
• grana
• stroma

Question 11

thylakoids

Answer 11

membrane bound network of flattened sac-like structures that function in converting light energy to chemical energy

Question 12

grana

Answer 12

interconnected stacks of thylakoids

Question 13

lumen

Answer 13

space in thylakoids

Question 14

stroma

Answer 14

fluid filled space between thylakoids and the inner membrane

Question 15

pigments

Answer 15

molecules that absorb only certain wavelengths of light
- make up composition of thylakoid membranes

Question 16

what is the most abundant pigment

Answer 16

chlorophyll
- transmits green light

Question 17

how many steps does the calvin cycle go through

Answer 17

three steps
fixation
reduction
regeneration

Question 18

fixation phase

Answer 18

• begins when CO2 reacts with RuBP
• fixes carbon
• produces two molecules of 3PGA

Question 19

reduction phase

Answer 19

• 3GA phosphorylated by ATP and reduced by accepting electrons
• product is phosphorylated three carbon sugar (G3P)

Question 20

regeneration phase

Answer 20

• rest of G3P keeps cycle going by serving as substrate

Question 21

where do the three phases take place in

Answer 21

stoma of chloroplasts

Question 22

one does one turn of the calvin cycle fix

Answer 22

one molecule of CO2

Question 23

why do sugars take so much chemical energy to be produced

Answer 23

because they store so much potential energy

Question 24

when is rubisco activated and inhibited

Answer 24

activated: regulatory molecules produced when light is available

inhibited: when CO2 is low in availability

Question 25

gluconeogenesis

Answer 25

synthesis of glucose

Question 26

what is combined to form sucrose

Answer 26

glucose and fructose

Question 27

sucrose

Answer 27

- disaccharide - one of the two main products of photosynthesis - produced in cytosol

Question 28

when is starch formed

Answer 28

photosynthesis is happening rapidly and sucrose is abundant

Question 29

starch

Answer 29

storage carb in cells of leaves and roots - produced inside chloroplast

Question 30

at night, what happens to the starch

Answer 30

broken down to glucose which is then used for cellular respiration or manufacture sucrose

Question 31

how do pigment molecules capture light energy

Answer 31

excitement of their electrons when photon is absorbed

Question 32

how is the excitation energy released as after photon is absorbed

Answer 32

fluorescence and heat

Question 33

antenna pigments

Answer 33

transfer absorbed light energy via resonance to reaction center

Question 34

photosystem II

Answer 34

- excited electrons transferred to plastoquinone - redox reactions used to generate proton motive force that drives creation of ATP

Question 35

what are the electrons from photosystem II replaced by

Answer 35

splitting water

Question 36

photosystem I

Answer 36

- excited electrons passed to ferredoxin

Question 37

what connects photosystem I and II

Answer 37

Z scheme

Question 38

what do the stomata regulate

Answer 38

exchange of CO2 and O2 between lead tissue of plant and environment

Question 39

when is photosynthesis stimulated and reduced

Answer 39

stimulated: presence of light reduced: sugar supplies are low OR CO2 availability is low

Question 40

what does rubisco catalyze

Answer 40

- fixation of CO2 to RuBP - addition of oxygen as well as CO2 to RuBP