The light-dependent and independent phase of photosynthesis

Question 1

what two phases can we split photosynthesis into

Answer 1

the light-dependent and light-independent phases

Question 2

what is the light dependent phase of Photosynthesis

Answer 2

Thefirstphaseofphotosynthesisis known as thelight-dependent phase. In this phase of photosynthesis, theradiant energyfrom the sun is harnessed.

Question 3

where does the dependent phase occur

Answer 3

in thegranaorstacks of thylakoids

Question 4

what are the steps in this phase

Answer 4

1. The sun’sradiant energyis absorbed by theleafand enters thechloroplasts. Here, thechlorophyllin thegranaabsorbs theenergy.
2. Water, absorbed through therootsof the plant and transported to theleavesvia thexylemvessels, enters thegrana.
3. Theradiant energycauses thephotolysisof thewatermolecules. Photolysis is thesplittingof awatermoleculeusinglight energy. The water molecule splits to form:
   
   • Hydrogen ions(H+) that areenergy-richand will be used in thelight-independent phaseof photosynthesis.
   • Oxygenthat is released back into theatmosphereas abyproductof photosynthesis.
4. Theradiant energyalso formsATP(adenosine triphosphate) throughphosphorylation. Thisenergycarriermoleculewill be used in thelight-independentreaction too.

Question 5

what is the independent phase

Answer 5

this is the second phase of photosynthesis

the products made in the first phase are essential for this phase to work

the reaction can occurwithoutthe presence oflight.

Question 6

where does the light - independent phase occur

Answer 6

Thelight-independentphase ofphotosynthesisoccursin thestromaof thechloroplastand makes use of theproductsformed during thelight-dependent phase

Question 7

what are the steps in independent phase

Answer 7

1. Carbon dioxide(CO2) enters thestomataof the leaves and istransportedinto thechloroplasts.
2. Thecarbon dioxidecombineswith thehydrogen ions(H) which were produced in the light-dependent phase. This happens with the help of theATPenergy-carrying molecules. This reaction producesglucose(CHO)+C6 H12 O6
3. Theglucoseis used by the plant incellular respirationand excess glucose can be stored asstarch.