In the following passage the numbered spaces can be filled with biological terms.

During the light-independent reaction of photosynthesis, carbon dioxide diffusing into the stroma of the chloroplast is fixed by combining with the 5-carbon compound (1). This reaction is catalysed by the enzyme (2). The unstable 6-carbon compound produced immediately splits to form two molecules of the 3-carbon compound (3). This is then reduced to the 3-carbon sugar (4) using ATP and reduced NADP from the light-dependent reaction.

Write the correct biological term matching each number:

(1) ___________________________________

(2) ___________________________________

(3) ___________________________________

(4) ___________________________________

Describe the light-independent reaction (Calvin cycle) of photosynthesis.