What are the starting materials and products of photosynthesis and cellular respiration?

The starting materials for photosynthesis are carbon dioxide, water and sunlight. Green plants have special cell structures called chloroplasts that contain a green pigment called chlorophyll. When chlorophyll is excited by sunlight in the presence of carbon dioxide and water, green plants are able to synthesize carbohydrates through photosynthesis.

It won't lose or gain electrons if it's a covalent bond it shares the electrons with another atom or atoms. if it is an ionic bond it will lose the 3 electrons on the outer shell and become a positively charged ion.  credit goes to @sunshinebaby of answers.yahoo.com.