photosynthesis

Question 1

what is the formula for photosynthesis

Answer 1

6CO2+ 6H20 +energy—> C6H12O6 + 6O2

Question 2

main purpose of light dependent reactions

Answer 2

-(Photo)
- convert light energy into chemical energy in the form of ATP and NADPH, these chemical energy molecules are used in calvin cycle to assemble sugar molecules

Question 3

main purpose of light independent reactions

Answer 3

• (synthesis)
• use chem energy from light dependent to assemble glucose
• main goal is to assemble glucose
• calvin cycle

Question 4

location requirments and products for light dependent reactions

Answer 4

• thylakoid membrane
• required: sunlight and water
• products: oxygen, NADPH, ATP

Question 5

location requirmeents and products for light independent reactions

Answer 5

• stroma
• requires: ATP, NADPH, CO2 and rubp (enzyme)
• products: glucose, NADP+ and ADP

Question 6

role of photosystem 2

Answer 6

absorb photons of light energy to energzie and transfer electrons and to create a proton gradeint (H+)

Question 7

role of photosystem 1

Answer 7

prdocue NADPH which is a energy carrier molecules and to generate a proton motive force

Question 8

where is energy passes in light dependent reactions

Answer 8

along electron accepting cholophyll A molecules called reaction center

Question 9

2 stages of light dependent reactions

Answer 9

1: captue solar energy and transfer it to electrons through the splitting of water
2: using energy to make ATP and transferring electrons to make NADPH

Question 10

what is a photsystem

Answer 10

clusters of cholorphyll and other pigments emeded in thylakoid membrane

Question 11

what is photolysis

Answer 11

splitting of water, occurs in thylakoid lumen

Question 12

what is NADP+

Answer 12

coenzyme electron carrier

Question 13

what is NADPH

Answer 13

electron donor that carriers electrons and hydrogen atoms to other molecules

Question 14

what is chemiosmosis,

Answer 14

synthesizing ATP using energy from H+ gradeint
process of ions moving across a semi permeable membrane from higher concentration to a lower one

Question 15

ATP synthase

Answer 15

emeded in thylakoid membrane and porvides the only pathway for H+ to move out

Question 16

reduction reaction

Answer 16

electron transfer in a chemical equation (gain of electron)
oxidizing agent
- always occurs with a oxidation reaction

Question 17

oxidation reaction

Answer 17

loss of elctrons
reducing agaent
reacts with oxygen

Question 18

first step in stage 1

Answer 18

• light strikes the cholorphyll photons excite the chlorophyll
• after chlorophyll captures light energy by absorbing photons and passing energy to electrons it is transfer to reaction center

Question 19

what causes splitting of water

Answer 19

light energy
water is dived into hydorgen ions, oxygen and electrons
oxygen is made and realses into atmosphere (exits stroma)
Hyrdogen ions remain in luem

Question 20

electron excitation second step in stage 1

Answer 20

electrons are excited and moved from lumen to cholorphyll
- electrons are transferred to PS1 through electron transport chain

Question 21

what is the electron transport chain

Answer 21

found along the thylakoid membrane, electron moev along this relasesing energy as they move (redox reaction)
every step down the ETC electrons give up some stored potential energy

Question 22

what happens when electrons reaches PS1

Answer 22

it is hit by light and become excited again

Question 23

what is energy realsed by PS1 used for

Answer 23

rejoin high energy electrons with hydrogen ions and NADP+ to produce NADPH (final electron acceptor)

Question 24

how do hyrdogen ions difuse into thylakoid membrane

Answer 24

cannot diffuse out because membrane is impermebale to them so uses chemiosmmosi
- energy realses from Electron tasnport chain pulls hydrogen ions into thyalkoid membrane (against gradeint)
- creates a + channel and a step gradeinent

Question 25

how is ATP synthesixed in light depndent reactions

Answer 25

using energy from H+ gradeint

Question 26

what is an action spectrum

Answer 26

sjows relative effectvieness of different wavelengths of light for photosynthesis, reflected by a response in the rate oxygen is released

Question 27

what is absorbance spectrum

Answer 27

relative amounds of light of different colors a compound absorbs

Question 28

what are light independent reactions

Answer 28

energy of ATP and reducing power of NADPH are used to reduce CO2 and make glucose occurs in stroma

Question 29

what is G3P

Answer 29

converts CO2 into glucose

Question 30

what is rubisco

Answer 30

enzyme catalszing carbon fixation

Question 31

what happens in carbon fixation

Answer 31

means carbon atom in CO2 is chemically bonded to a pre existing molecule in stroma - this molecule is RuBP (5-carbon molecule) - this results in a six carbon compound that is highly unstable - this immediately breaks down into 2 identical carbon compounds (3-PGA) - these 3-carbon compounds are the first stable products - plants that demonsatte this are called C3 plants CO2+ RuBP--> unstable C6--> 2C3

Question 32

what happens in the reduction part of calvin cycvle

Answer 32

- newly formed 3 carbon compound are in a low energy state - to convert them to high energy they are first activated by ATP and then reduced by NADPH - this results in 1,3 bisphosphoglycerate (1,3-BPG) - pair of electron from NADPh reduced 1,3-BPG into G3P - results in 6 G3P molecules fro 3 CO2 - 1exits cycle to form glucose and other high energy molecules ( 2 G3P forms 1 glucose) - 5 G3P are used in regeneration phase

Question 33

what happens in replacing RuBP stage

Answer 33

- most of reduced G3P molecules are used to make more RuBP, energy supplied by ATP is required to break and reform the chemical bonds to make the 5 carbon RuBP from G3P

Question 34

how many times must the calvin cycle must be completed in order to synthesize one molecules of sugar

Answer 34

6 times

Question 35

of the 12 G3P molecules prudced in 6 cycles what do each of them do

Answer 35

- 10 are used to regenerate RuBP - 2 are used to make glucose

Question 36

light reaction summary

Answer 36

- 6H2O split= photolysis - 6O2 released in atmosphere electron move along teasnport chain - 18 ADP to 18ATP in photosytem 2 from the hydrogen ion gradeint - 12 NADP+ reduced to 12 NADPH on photosytem 1

Question 37

calvin cycle summary

Answer 37

- 6 moleucles of CO2 combine with 6 molecules of RuBP -n12 molecules are PGA are formed - 12 NADPh are oxidized - 18 ATP are consumed - 12 G3P are formed - 10 G3P are changed into RuBP - 2 G3P molecules are converted into glucose

Question 38

how long can plant carry out light independent reaction if place in the dark

Answer 38

until it runs out of ATP and NADPH supplied by light reaction

Question 39

why does plant not immediatly produce glucose when placed in the light

Answer 39

must produced ATP and NADPH - light independent requires products from light dependent