photosynthesis

Question 1

what is the name of the things that do photosynthesis

Answer 1

photoautotrophs
photo-light energy
auto-self
troph-feeder

Question 2

autotroph

Answer 2

get own carbon from inorganic source (feed themselves)

Question 3

Chemoautotroph

Answer 3

get energy by breaking down chemicals

Question 4

carbon fixation

Answer 4

Atomospheric CO2 is ‘fixed’ (attached) to an organic molecule called RuBP
The enzyme Rubisco mediates this rxn
RuBP + CO2 forms unstable intermediate
Intermediate splits into 2 PGA (3 C each)

Question 5

light reactions begin at

Answer 5

photosystem two- chlorophyll a p680

Question 6

Light-harvesting complex

Answer 6

surrounding complex of proteins and pigments containing

chlorophyll a, chlorophyll b, carotenoids pass energy along to reaction center

Question 7

reaction center

Answer 7

holds 2 special chlorophyll a molecules and primary e-acceptor protein

Question 8

light reactions

Answer 8

start at photosystem two
go to light harvesting complex
which go to the reaction center where electron jumps out of chlorophyll a onto 1˚e- acceptor chlorophyll a of photosystem II is now P680+

Question 9

photosystem 2

Answer 9

more modern version PS w/ specialized enzyme (p680)

Question 10

light reaction step two

Answer 10

water is split which releases O2 as a waste product, H+ go into thylakoid space and sends an e- through PS 2 for e- transport chain

Question 11

step 3 light reaction

Answer 11

e - from PS 2 move down e- transport chain
Give energy to proton pumps
e- enter photosystem I
light Re-energized e- in e- chain to exit thylakoid
And are picked up by NADP+
NADPH moves to Calvin cycle to provide reducing power

Question 12

step four light reaction

Answer 12

Proton pumps powered by e-transport chain
Pump H+ ions into center of thylakoid
H+ ions flow out of thylakoid space through ATPase by facilitated diffusion
Energy of flowing H+ used by ATPase to make lots of ATP
ATP sent to Calvin cycle to provide energy

Question 13

light independent reactions

Answer 13

Use ATP to make glucose
Take place in the stroma
Require ATP and NADPH from light rxn
Require CO2 from atmosphere
Stroma is filled with thousands of enzymes
Hundreds of Calvin cycles are running simultaneously

Question 14

how many cycles of the calvin cycle forms a glucose

Answer 14

six cycles

Question 15

photosynthesis waste product

Answer 15

oxygen

Question 16

chemical put in to photosynthesis

Answer 16

water

Question 17

useful thing you get out of photosynthesis

Answer 17

NADPH and ATP

Question 18

calvin cycle PGAL formation

Answer 18

ATP from light rxn gives a phosphate group to each PGA by substrate level phosphorylation
NADPH reduces each PGA (adding H to them) making them into PGAL (Pi is released)

Question 19

PGAL also called

Answer 19

G3P

Question 20

calvin cycle reformation of RuBP

Answer 20

2 of the 12 PGAL are spit out of the cycle and made into glucose
The remaining PGAL are reformed into RuBP using energy from more ATP
Most glucose is converted to sucrose for transport or into starch for storage

Question 21

photosynthesis chemical equation

Answer 21

6 CO2 + 12 H2O –> C6H12O6 + 6 O2 + 6 H2O

Question 22

photosynthesis equation with net water

Answer 22

6 CO2 + 6 H2O –> C6H12O6 + 6 O2

Question 23

evolution of photosynthesis

Answer 23

1st photosynthetic bacteria did cyclic psyn
Only makes ATP not sugar
Still used by many bacteria

Question 24

Evolution of PS II

Answer 24

Non-cyclic psyn because e- obtained from H2O (not recycled)
Allowed production of high energy carbs
A way to transport & store chemical energy
Allowed larger more complex organisms
All plants and some bacteria have PS II and do non-cyclic psyn

Question 25

chloroplast structure

Answer 25

green in leaves
wax on the outside
stoma strata space in between to open and close for CO2 to enter

Question 26

waxy cuticle used to

Answer 26

prevent dehydration

Question 27

closing stomata causes

Answer 27

increase in O2 and decrease in CO2

Question 28

photorespiration

Answer 28

closed stomata so more O2 less CO2
Rubisco starts binding to O2
Puts O2 into calvin cycle
bad less glucose

Question 29

plants that do photorespiration are called

Answer 29

C3

Question 30

how do plants avoid photorespiration

Answer 30

Close stomata but keep CO2 levels near rubisco high by doing C4 cycle in mesophyll cells
In C4 cycle carbon fixation binds CO2 to PEP instead of RuBP
The enzyme binds CO2 to PEP ignores O2
PEP + CO2 = oxaloacetate ( a 4C molecule)
Oxaloacetate converts to malate
malate drops off CO2 to rubisco in bundle sheath cells that run C3 calvin cycle

Question 31

PEP + CO2 =

Answer 31

oxaloacetate ( a 4C molecule)

Question 32

CAM plants

Answer 32

cacti and desert plants
fix carbon by C4 cycle only at night
Store malate until day time
Close stomata and us malate as CO2 source to run Calvin cycle in day time when ATP and NADPH become available

Question 33

Carotenoids absorb

Answer 33

violet and bluegreen light

Question 34

carotenoids protect the leaf from

Answer 34

excessive light

Question 35

what kinda of reaction is photosynthesis

Answer 35

uses light nergy to build

catabolic

Question 36

photosystem one

Answer 36

p700

Question 37

what are the products of the light reactions/ ET chain and where are they sent

Answer 37

NADPH and ATP sent to the calvin cycle

Question 38

what kind of reaction is the calvin cycle

Answer 38

Endergonic, anabolic reaction forming

glucose

Question 39

parts of photosynthesis

Answer 39

e- transport chain/light reactions

calvin cycle where carbon fixation, PGAL formation, and RuBP formation take place

Question 40

where does the calvin cycle happen

Answer 40

in bundle sheath cells