AEROBIC RESIRATION: (making energy using oxygen)

 
1ST step- (GLYCOLYSIS - splitting glucose):
Remember that you need to use energy to make energy. (That's why you have to get yourself up and away for the TV - and out to get some exercise!!! You will feel energized AFTER you have gone and expended some energy.) Therefore, the first step uses ATP to gain ATP.

C₆H₁₂O₆ + 2 ATP ------> 2 pyruvic acid + 4 ATP

Pyruvic acid is simply half of a glucose molecule - we've chopped it in half.


You made 4 molecules of ATP. Since you needed 2 molecules of ATP for the reaction, the NET gain is 2 ATP.

2nd step - the oxidation step:

Pyruvic Acid + O₂ ------> 34 ATP + CO₂ + H₂0

Wow! When you add oxygen, the pyruvic acid molecules makes 34 ATP molecules. That's a lot of energy from a single glucose molecule! Those by-products of water and carbon dioxide diffuse out the cell and are carried away.
If you put steps 1 & 2 together, here's what you did:

C₆H₁₂O₆ + 6 O₂----> 36 ATP + 6 CO₂ + 6 H₂O

Sound familiar? Day one??? This is important stuff that runs living things!!! Respiration!!
 

 
Some organisms don't use oxygen to make energy.
The first step of their respiration is GLYCOLYSIS (same as above). So they produce 2 ATP. Not much. Then again, yeast and bacteria don't need a whole lot of energy.
In their next step, they turn the pyruvic acid into 2 products we use in baking and brewing - carbon dioxide and alchohol!
 

Yes - good for you if you remember this!
 

Now - believe it or not, there is a time when humans undergo anaerobic respiration - it is when we work our muscles so hard that we deplete their oxygen supply.In this case, the pyruvic acid molecules don't turn into alcohol and carbon dioxide (otherwise you'd feel a little tipsy after exercise!). Instead , the pyruvic acid turns into something that makes your muscles sore. Lactic Acid!
 
 
 
 

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