yea, for sure on the actual DAT, the number you need to remember is 36
I agree with this statement. The DAT is meant to test general knowledge and Campbell's, as far as I know, still uses 36 ATP as its value. This value would still hold true for Prokaryotes as they don't have to transport ATP into/out of organelles. Sure, for humans the "actual" value should be either 30 or 32 (depending on the shuttle) but I would say memorize 36, I don't think you can go wrong.
Here is a more in depth explanation that I posted in an earlier forum should you be interested in why it is 2.5 vs. 1.5:
"The difference results in how NADH are transported into the mitochondria b/c (we all KNOW) glycolysis occurs in the cytosol, we can only use NADH and FADH2 in the electron transport chain (ETC). We must "shuttle" them into the matrix for usage. Two "shuttles" exist that may transfer the high energy compounds from the cytosol to the matrix:
1. The glycerophosphate shuttle uses 3-phosphoglyerol and transfers the e- from NADH to complex 2 of the ETC. Complex 2 does NOT transfer H+ into the intermembrane space unlike complex 1. The total amt of H+ transfered into the intermembrane space using this shuttle is 6 H+.
2. The malate aspartate shuttle transfers the e- from NADH into the ETC using aspartate which transfers the high energy compound into the ETC complex 1, which transfers 4 H+ into the intermembrane space for a total of 10 H+ once you get to the end of the ETC
Okay, so why the heck does this matter? H+ are essentially what drives ATP synthesis, so the more H+ moved into the intermembrane space, the more ATP can be produced by ATP synthase.
So now, it takes 4 H+ to turn ATP synthase 120 degrees to make one ATP (look up structure on Wiki);
10 H+/ 4 H+ = 2.5 ATP for Malate Aspartate Shuttle
6 H+/ 4 H+= 1.5 ATP for Glycerophosphate shuttle
Note: The glycerophosphate shuttle is found in tissues that need a very rapid supply of energy, such as the wings of hummingbirds and insects; it is very rapid but less efficient. The malate aspartate shuttle is found in tissues like out muscles and most other cells (although muscles may derive energy from more sources than just glycolysis).
Also note, NADH and FADH2 produced during fatty acid breakdown is already in the matrix, therefore all NADH from FA's produce 2.5 NADH.
As far as total ATP from glycolysis, I am inclined to go with this answer:
Needed for glycolysis: 2 to initiate (one for hexokinase and one for phosphofructokinase)
Made from glycolysis: 4 ATP ( 2 from Phosphoglycerate kinase and 2 from Pyruvate Kinase, for each 1,2 BPG from Glucose)
2 NADH from Glyceraldehyde 3-phosphate DH=> (2.5x 2 ATP max)=5 ATP
SO TOTAL/NET= 4 + 5 - 2 = 7.
Under minimal conditions using the glycerophosphate shuttle, which I would not assume they would ever ask, the answer would be 4+3-2=5
HOWEVER: besides what we know to be true, almost all entry level bio books say that NADH= 3 ATP, they round up. Therefore the BEST answer for TEST day would be most likely 8 ( I believe).
Hope this helps. I feel sorry for those who haven't taken biochem now.
The total ATP produced from 1 glucose are this (according to Biochem books, but for the DAT, memorize whatever Campbell's says)
2 pyruvate from glucose each produce 12.5 ATP (from 3 NADH @ 2.5 ATP each, 1 FADH @ 1.5 ATP each, 1 GTP, don't forget the NADH from pyruvate DH @ 2.5 ATP each) in the TCA, ETC, and Oxidative phosphorylation cycle.
2 NADH from glycolysis, either 1.5 or 2.5 each
2 ATP from Glycolysis
So maximum should be 32 (12.5 x 2 + 5 +2) minimum should be 30.
And again, despite what this says, I would still go with 36 on test day unless it specifically says "in mammals" how much ATP etc...
