Light-dependent reactions

what is oxidisation ?

loss of electrons, loss of hydrogen ion or gain of oxygen

• energy given out

what is reduction ?

gain of electrons, gain of hydrogen or loss of oxygen

• energy taken in

what is photophosphorylation?

add inorganic phosphate molecules to ADP making ATP

what is photolysis ?

splitting water into H+ ions (protons), electrons & oxygen

where does photophosphorylation & photolysis take place ?

on the thylakoids

what are the products of light dependent reaction that passes to light independent reaction ?

• reduced NAPD (NADPH)

• ATP

waste molecule of light dependent reactions that leave the plant ?

oxygen leaves the plant

molecules from light dependent reaction that is reused ?

• H+ ions

• electrons

Why can't plants only rely on APT & also need to respire ?

• ATP not made in the dark

• not alot of ATP made

• cells without chlorophyll can't make ATP

• can't be transported around organism but glucose can

what are the steps of chemiosmotic theory ?

1. H+ ions produced by phospholysis of H2O, move into thylakoid from stroma using active transport using energy released from the electron released from chlorphyll

2. H+ ions can only pass from thylakoid space to stroma through ATP sythase channel proteins (rest of membrane is impermeable)

3. as H+ ions pass through the channels, they cause enzymes to change shape. This enzyme catalyses ADP + Pi → ATP

how are H+ ions moved in to thylakoid during chemiosmotic theory ?

H+ ions moved by active transport

how are H+ ions moved out of thylakoid during chemiosmotic theory ?

H+ ions moved by facilitated diffusion

how are protons transported into the thylakoid during chemiosmotic theory?

using a proton pump which actively transports inot the thylakoid using energy from electrons from chlorophyll

where is the low concentration of proteins in chemiosmotic theory ?

in the stroma (outside the thylakoid)

where is the high concentration of protons in the chemiosmotic theory ?

inside the thylakoid

what is the equation for photolysis ?

2H2O → 4H+ +4e- + O2

How are chloroplasts adapted for light dependent reactions ?

• thylakoid membrane has large surface area to allow chlorplasts to attach to

• network for proteins in grana mean chloroplast held in precise place for maximum absorption of light

• granal membranes contain ATP synthase channels to catalyse production of ATP

• cchloroplasts contain DNA & ribsomoses to manufacture some of the proteins for light dependent reactions

steps of phosphorylation?

• photon of light hits chlorophyll molecule

• 2 high energy e- picked up bby e- carriers

• e- pass through e- carriers on thylakoid molecule

• e- released to form ATP

• low energy e- left over

afterward phosphorylation

• e- passed through thylakoid combined with H+ ions from photolysis & attach to NADP

• NADPH

steps of photolysis ?

• photon of light hits a chlorphyll molecule

• chlorphyll short of e- & must be reproduced

• light splits water into H+, e- & O2

what happens to the oxygen after photolysis ?

used in repiration or diffusion

what happens to the e- after photolysis ?

combine with chlorphyll

what are the steps after photophosphorylation & photolysis?

• e- passes through thylakoid & combined with H+ ions from photolysis & attach to NADP

• NADPH (reduced NADP) formed & enters light independent reaction