lant cells can synthesize energy-rich organic molecules, and later break them down to extract that energy for performing life processes where does it occur?.

Two processes were described in this question, hence, the location of the two processes are as follows:

synthesize energy-rich organic molecules- CHLOROPLAST

Break them down to extract energy- MITOCHONDRIA

Explanation:

Plant cells are unique cells capable of synthesizing their own food via a process called PHOTOSYNTHESIS. The process of photosynthesis, which occurs in an organnelle called CHLOROPLAST, synthesizes a sugar (glucose), which is an energy-rich organic molecules i.e. it stores energy in its chemical bonds.

However, to harness the usable form of energy stored in the chemical bonds of Glucose, the cells need to break down the glucose molecule. Plant cells break down glucose in a process called CELLULAR RESPIRATION in order to convert the stored energy in Glucose to a usable form called ATP. This extraction of ATP molecule needed for every life process of the plant cell is carried out in another organnelle called MITOCHONDRION.

all matter is made up of atoms

in any element all atoms are the same

elements in a compound are always in a constant ratio: apex