Describe the overall changes in matter that occur during the light-independent reactions. what does the plant start with and what does it end with? what is the source pf energy that powers this change

In the light-independent reactions, the plant starts with carbon dioxide and ends up with glyceraldehyde-3-phosphate (G3P). It uses ATP and NADPH from the light-dependent reactions as energy sources  

Explanation:

Step 1: CO₂ adds to ribulose biphosphate (RBP) to form a six-carbon sugar that immediately decomposes into two molecules of 3-phosphopglycerate (3-PGA).

CO₂ + RBP ⟶ 2 3-PGA

Step 2. A phosphate group adds to the 3-PGA to form 1,3-biphosphoglycerate (1,3-BPG).

3-PGA + ATP ⟶ 1,3-BPG + ADP

Step 3. NADPH reduces the 1,3-BPG to G3P

1,3-BPG + NADPH ⟶ G3P + NADP⁺

Most of the G3P is regenerated into RBP, but some leaves the cycle to become glucose.