You are here:

Biology/photosynthesis

Advertisement


Question
What is the source of oxygen atoms in glucose formed by photosynthesis? Also the source of hydrogen atoms and carbon atoms in glucose formed by photosynthesis?

Answer
In photosynthesis, glucose is formed by the interaction of sunlight (an energy source), carbon dioxide, and water according to this equation:

CO2+2H2O+Photons-->Glucose+O2+H2O

Carbon dioxide provides the carbon and oxygen atoms for the formation of glucose. Water provides the hydrogen atoms (specifically, it provides protons, which are hydrogen atoms that have lost an electron to become H+). The oxygen on the right side of the equation was previously the water on the left side of the equation--it has been oxidized, which means that it has lost electrons. Excess water remains unchanged in the reaction and appears on the right side of the equation as a result.

The websites below discuss photosynthesis at various levels of complexity, depending on your interest:

http://www.life.illinois.edu/govindjee/linksPSed.htm
http://www.life.illinois.edu/govindjee/paper/gov.html
http://scienceaid.co.uk/biology/biochemistry/photosynthesis.html
http://www.rsc.org/education/teachers/learnnet/cfb/Photosynthesis.htm
http://www.life.illinois.edu/govindjee/photosynBook.html  

Biology

All Answers


Answers by Expert:


Ask Experts

Volunteer


John Locke

Expertise

I will answer all biology-related questions through the undergraduate level. I will explain unclear concepts and suggest approaches to solving problems, but would prefer not to completely solve homework problems for you. If you are completely stumped on homework, tell me what you already know and I will help you as much as possible. Please do not ask me for ideas on school research projects; part of research is determining a suitable area of investigation, and that's not a task that should be completed by someone else. Please don't simply send me your homework for solutions. If you are having difficulty after you have started an analysis, I will be happy to direct your thinking; in particular, I would prefer to not simply solve pedigrees for students, but I will be happy to assist in solving pedigrees that you have already started. If you don't understand how to analyze a pedigree, I'd highly recommend watching this video, in which a biology professor explains the basic concepts of pedigree analysis: http://www.youtube.com/watch?v=HbIHjsn5cHo

Experience

I have a BS in Bioengineering with a concentration in Chemical Engineering (which included a heavy focus on biology), and have taught biology, biochemistry, and related subjects for some time now.

Education/Credentials
BS Bioengineering, Penn State University MCAT/DAT/OAT Instructor

©2012 About.com, a part of The New York Times Company. All rights reserved.