I really want to know what the second phase of photosynthesis (in the dark) is. I have a fair understanding of the first cycle where molecular oxygen is generated under the influence of light, but I don't understand the second cycle which can take place in the dark. It would greatly help to have a graphic of the second phase of photosynthesis.

Note: it is not for my homework, but for my own understanding. My textbook doesn't explain things very well.

  • 1
    $\begingroup$ I believe you are going to have to either elaborate on your question greatly and put forth some effort in specifics of what you are asking $\endgroup$
    – Macedon93
    Jan 4, 2015 at 20:52
  • 1
    $\begingroup$ photosynthesis has 2 phases.the first one is made in light,were oxygen is produced(i know this phase cause is easier and my teacher has it very good explained).The second phase is made in dark,were dioxide carbon is produced,but i don't know why and how.that's why i asked... $\endgroup$
    – user16901
    Jan 4, 2015 at 21:20
  • 2
    $\begingroup$ There are more than enough resources you can seek online to find the answer. Google the calvin cycle $\endgroup$
    – Macedon93
    Jan 4, 2015 at 21:24
  • $\begingroup$ actually i have,and i have found a lot of answers.but i posted here too,because i wanted even more answers. but thanks for your answer :) $\endgroup$
    – user16901
    Jan 4, 2015 at 21:28
  • 1
    $\begingroup$ I've voted to close because it seems like a homework question. What specifically is unclear to you about the second phase? Why does it confuse you more than the other phases? $\endgroup$
    – James
    Jan 5, 2015 at 14:36

1 Answer 1


Here's an overview of both the Light and Dark cycles of photosynthesis, which looked particularly useful to me as it shows that the energy-carriers ATP and NADPH2 generated through solar energy are used in the dark cycle to generate sugars.


Here is another one that shows more details on the precursors involved in the Calvin cycle:


As commented by others, googling 'dark cycle' or its synonyms will give thousands of optional images to choose from if these don't suffice. The first one is taken from tutorvista.com the second one from users.rcn.com.

  • 1
    $\begingroup$ The dark reactions don't necessarily need to be in the dark; they're called that because they don't require light. $\endgroup$
    – canadianer
    Jan 5, 2015 at 2:29
  • $\begingroup$ yes you are right $\endgroup$
    – user16901
    Jan 5, 2015 at 6:26

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.