Question

Please give me a VERY detailed explanation about the reactions and changes that happen to a CARBON ATOM during...
Photosynthesis (the light-dependent AND light-independent reactions),
When the Carbon Atom is transitioning between photosynthesis and respiration,
What happens to the Carbon Atom during cellular respiration OR fermentation. Also...
You do not HAVE to add these details but it would be nice if you would Add descriptions of the molecules involved in each process and the movement of electrons and energy as the carbon atom moves from one reaction to another! It might seem like a lot of explaining, BUT would help me a WHOLE BUNCH!!

Answer 1

kI have to do work for Biology and if I understood these things I would get the assignment a LOT better! I have researched it but I always get some long complicated explanation that I never understand. So please explain what happens to a Carbon Atom as it goes through each of these things. I know it might take some time on your part but it would REALLY help me understand a lot! PLEASE only post website addresses that is right to the point of what I'm asking!

Answer 2

@JustCurious if you are online right now than I can help you bit by bit until you understand. Okay? Start by asking me one question that I can explain because your question up above is a little confusing... :D

Answer 3

Very detailed explanation? During cellular respiration you have a molecule with a lot of carbons being oxidized into a molecule with very few carbons.

During photosynthesis, you have kind of the opposite. Carbon dioxide is uptaken using the rubisco molecule (during the light reactions there's no use of carbon for what you're asking about, it's during the "dark" reactions where carbon is used) to make molecules with many carbons - so it gets "reduced" if you will.

Answer 4

Err, sorry, I didn't give you a very detailed description. For that you really need to sit down and read a textbook so as to see exactly what happens becasue each thing you mentioned involves a very lengthy and complicated mechanism where there are intermediates and cofactors and all kinds of stuff.

Answer 5

And if you try and get a very detailed answer from here, although we try to give accurate responses you can never take our word for anything 100%. The devil's in the details, and the details are the easiest ones to forget.

Answer 6

@spatcher Great last line!!
@vgress OK! First Question, What happens to a carbon atom during photosynthesis? It only has to be 2-3 sentences, and list the reactions, if there are any, of the carbon atom to light-dependent and the light-independent during photosynthesis. You only have to write enough to where I get the jist of it!

Answer 7

If anyone else cares to answer, please do.

Answer 8

Hey there,

Here's a quick drawing of a general overview of what's going on with the carbon atom.

In green is the chloroplast, in blue is the mitochondrion. Purple is the cell membrane. Carbon atoms are turquoise. We'll follow the one specially marked light blue as an example of one possible path a carbon might take.

Let's start in the bottom right corner!

CO2 (blue carbon attached to two red oxygens) diffuses into the cell. It enters the chlroplast. A special enzyme (depicted as a golden triangle) called Rubisco catalyzes the carbon fixation reaction: the carbon dioxide is attached to a 5 carbon compound known as ribulose bisphosphate. This is step one of the Calvin Cycle. This reaction forms an unstable 6 carbon compound which quickly splits into two 3 carbon compounds. The energy frmo the light reactions, in the forms of ATP and NADPH, is stored into these three carbon compounds. Per every 3 carbon atoms, one 3 carbon compound exits this cycle into the cytoplasm. Through a set of reactions, this 3 carbon compound (aaka glyceraldehyde 3 phosphate) is transformed into a glucose molecule. Glucose then can be stored or used for other activities, but in our case, we'll shuttle it back into cellular respiration.

As you know, the first step is glycolysis. The specific reactions of glycolysis are beyond the scope of my drawing abilities; you can find them anywhere online though. At the end of glycolysis, you're left with two pyruvate molecules. Pyruvate (3 carbons) enters the mitochondrion, becoming acetyl co-A (2 carbons) in the process.

Here begins the Krebs Cycle. Acetyl Co-A combines with oxaloacetate (thhe 4 carbon compound) to form citrate (the 6 carbon compound). The 6 carbon compound is broken down to a 4 carbon compound, in each step releasing a carbon dioxide molecule. Here is where our original carbon, fixed back in the chlroplast, can be released. Oh and - the four carbon compound in the Krebs cycle continues to lose energy to NADH and FADH2, which carry it over to the electron transport chain (yellow arrows) which ultimately generates ATP.

Hope this helps! Unfortunately I do not have the time to go into the specifics of the reactions. I also want to point out that I basically skipped over the light reactions and the electron transport chain - this is because carbon is not directly involved.

Answer 9

Just want to emphasize that this is only one of a multitude of possible paths the carbon atom could actually take...for example, it could spend a few loops inside the Krebs or Calvin cycles before being released as CO2 once more.