Unit 3: Cellular Energetics

Question 1

catabolism

Answer 1

the breakdown of molecules
ex: hydrolysis, cellular respiration, exergonic

Question 2

anabolism

Answer 2

builds polymers
ex: dehydration synthesis, photosynthesis, endergonic

Question 3

autotrophs

Answer 3

(producers) use light energy to make organic molecules

Question 4

heterotrophs

Answer 4

consume organic molecules from other organisms for energy and carbon

Question 5

photosynthesis

Answer 5

6CO2 + 6H2O + Light Energy -> C6H12O6 + 6O2

converts light energy chemical energy of food

Question 6

chloroplast

Answer 6

site of photosynthesis in plants found in the cells of the mesophyll (the inner tissue of the leaf)

Question 7

stroma

Answer 7

dense fluid within chloroplast

Question 8

stomata

Answer 8

pores in leaf

Question 9

chlorophyll

Answer 9

green pigment in the thylakoid membranes of chloroplast

Question 10

redox reaction

Answer 10

water is split, energy transferred with H+ to CO2, sugar water is oxidized, carbon dioxide is reduced

Question 11

photons

Answer 11

a particle of light absorbed by the chloroplast

Question 12

light reactions

Answer 12

(thylakoid) split water, release oxygen, produce ATP and NADPH for reducing power

Question 13

calvin cycle / dark reactions

Answer 13

(stroma) forms sugar from carbon dioxide, using ATP for energy and NADPH for reducing power

Question 14

photosystem

Answer 14

a reaction center that absorbs different wavelengths of light

Question 15

calvin cycle: step 1: carbon fixation

Answer 15

Rubisco fixing CO2 to RuBP, producing two molecules of 3-PGA

Question 16

calvin cycle: step 2: reduction

Answer 16

3-PGA molecules made through carbon fixation are converted into glucose. this stage obtains energy from ATP and NADPH formed during light dependent reactions. G3P exits the cycle

Question 17

calvin cycle: step 3: regeneration of RuBP

Answer 17

the remaining 5 G3P molecules get rearranged to form 3 RuBP molecules

Question 18

where do the light reactions take place?

Answer 18

thylakoid membrane

Question 19

what are the primary cells responsible for photosynthesis

Answer 19

palisade mesophyll

Question 20

steps of the light dependent reactions: photolysis

Answer 20

step 1: light strikes chlorophyll in photosystem II, causes electrons to become excited

step 2: water is split to replace electrons lost by photosynthesis II, this produces hydrogen ions

Question 21

as electrons travel down the electron transport chain (ETC) their energy is used to pump hydrogen ions across the membrane into the …

Answer 21

thylakoid space

Question 22

what does light do when it strikes the chlorophyll molecules of photosystems I and II?

Answer 22

light causes electrons to get excited (gain energy) and travel down an electron transport chain embedded in the thylakoid membrane

Question 23

after light excites electrons and they leave photosystem II to travel down the first electron transport chain, how are these electrons replaced to photosystem II?

Answer 23

water is split and the electrons are given to the chlorophyll molecules of photosystem II

Question 24

exergonic

Answer 24

metabolic process involving release of energy

Question 25

endergonic

Answer 25

metabolic process involving absorbing energy