ATP glycolysis

[pistolpete007]

how many atp results in aerobic glycolysis

A. 2 Atps
b. 4 atps
c. 6 atps
d. 8 atps

the answer is 8 atps....i thought it was 2?

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[tsav23]

I don't know why that would be the answer. To my knowledge. 4 ATPs are produced during glycolysis. It requires 2 ATP to start glycolysis in the cytoplasm, and after the breaking up of glucose to 2 moles of pyruvate you make 4 ATP, causing a net gain of 2 ATP.

 

[zriceman]

2 ATPs (net) are produced in addition to 2 NADH which produces only 2 ATP each since NADH has to travel across the mito membrane.

I think the answer is 6. Any other thoughts?

 

[pistolpete007]

my bad the anwe was 6 ATPS....do u think the word aerobic has nething to do w/ it? for not being the usual 2?

 

[osimsDDS]

yea the wording is very important, since glycolysis can be anaerobic and still produce ATP via fermentation by recharging the NAD+ it can still produce 2 net ATP per glucose molecule each time....But since it is aerobic, like others have said, it goes through the whole ETC process with the 2 NADH's that only produce 2 ATP instead of 3 normally.

Glycolysis = 2 ATP net
Oxidative Phosphorylation Anaerobic = 2 NADPH (from Glyc.) x 2 ATP (per NADH) -----> 4 ATP from aerobic respiration

SOOOO TOTAL will give you 6 ATP from aerobic 2 ATP from Anaerobic...

 

[baedero1]

2NADH X 3ATP = 6ATP
2 ATP net

so total 8 ATP

 

[osimsDDS]

wrong, the NADH from glycolysis only make 2 ATP per NADH instead of 3 ATP cuz they have to be transported into the mitochondria from the cytoplasm, its 6 not 8

 

[DentalP87]

wrong, the NADH from glycolysis only make 2 ATP per NADH instead of 3 ATP cuz they have to be transported into the mitochondria from the cytoplasm, its 6 not 8

wrong. we have 4 ATP formed from substrate level phosphorylation (2 PGAL molecules), 6 ATP from 2 NADH (2 PGAL molecules), and two ATP used to phophorylate/oxidize glucose:

4 + 6 -2 = 8 net ATP

 

[OMFS08]

OsimsDDS is right, you can only get 2 ATP from the NADH in glycolysis instead of the usual 3 ATP because 2 of the ATP are transported into the mitochondria. Just read this 3-4 days ago. I am pretty certain the answer is 6ATPs

 

[osimsDDS]

the question isnt asking for substrate level phosphorylation its asking for glycolysis under aerobic conditions...

 

[vvvv]

well glycolysis only produce 4 ATP (2 net ATP). but if you calculate the ATP that can produce from the NADH which is the produce of the glycolysis, why don't you calculate the ATP that can be produced by pyruvate? I think the answer is not right.

FYI: anaero res produce 2 ATP, this ATp come from glycolysis,

 

[TheWiredNerv]

The question seems to be asking about how many ATP can you get from all the products of glycolysis. In other words, how much ATP can you get when you reach Pyruvate. The answer clearly is 8. You get 4 ATP from glycolysis as product. If you don't believe me then look at the biochemical reactions and you will see 2 ATP are produced from 1,3 BPG to 3-phosphoglycerate and another 2 from PEP to pyruvate. That is 4. You also get 2 NADH. That gives you 4 ATP via oxidation phosphorylation. The amount of ATP that results is 8 ATP. D

2 net ATP and then 2 NADH, which give you 2 ATP a piece so that is 4 ATP.


Read the question carefully. No where in the question does it mention how much NET ATP you get.

Unless they are asking for NET ATP then it would be 6.

 

[futuredent22]

The OP corrected himself and said the answer is 6 ATP

anaerobic glycolysis results in 2 ATP. the the two NADH molecules each lead to 2 more ATPs.

the question does specify that it is looking for the NET production of ATP. The key word is "results." Anaerobic glycolysis RESULTS in 2 ATP. Not 4.

 

[futuredent22]

Further proof that the question is inherently asking for the NET production of ATP and not the gross production:

If they asked for the gross production of ATP, the answer would really be 10. 4 ATP is the gross product from anaerobic glycolysis, and 6 ATP is the gross product from the NADH.

However, 10 ATP is not how much you get from aerobic glycolyis. 2 ATP is the cost in the beginning of glycolysis, and 2 ATP is the cost of transport of the two NADH to the mitochondria.

(4-2) + (6-2)= 6 ATP

 

[lemoncurry]

NADH produces approx 2.5 ATPs, actually (according to my biochem class last quarter), so the answer should be 7 🙂

 

[vvvv]

NADH produces approx 2.5 ATPs, actually (according to my biochem class last quarter), so the answer should be 7 🙂

I agree but if you could tell me why you count ATP from NADH which is the product of glycolysis to total ATP produced, but you dont count pyruvate.

 

[DCRedskinsRule]

Osims is 100% right. 6 total. 4 from the 2NADH (instead of normal 6) and 2 net from Glycolysis.

 

[osimsDDS]

first of all I dont believe pyruvate decarboxylation is part of glycolysis, so assuming that pyruvate decarboxylate gives up its 2 NADH's to the ETC is wrong because its not part of glycolysis....glycolysis is just production of 2 Pyruvates, 2 Net ATP, and 2 NADH's that are counted for 2 ATP per NADH...

 

[osimsDDS]

Again the main point here is GLYCOLYSIS not substrate level phosphorylation which is glycolysis, pyruvate decarboxylation, and krebs...

You guys are thinking about this too much, we should all just go back to the basics, however, I believe this thread has made us professionals at cell respiration haha

36 ATP total for eukaryotes
38 ATP total for prokaryotes (no mito)

 

[yakuza]

Isn't this pretty simple..........

when you go from 2 PGAL ----> 2 Pyruvates, you make 4 ATP + 2 NADH (each NADH makes 2 ATP) so that makes 8 ATP total. Then subtract 2 ATP b/c two were used.

 

[Streetwolf]

NADH produces approx 2.5 ATPs, actually (according to my biochem class last quarter), so the answer should be 7 🙂

Yeah except since it uses FADH2 to cross into the mito it would actually only generate 1.5 ATP each meaning the *REAL* answer is 5 ATP 🙂

You don't count pyruvate because we're talking about things that appear during glycolysis. Pyruvate itself does NOT go through the ETC and make ATP. However the NADH produced during glycolysis does so that counts.

Of course this problem still goes by NADH = 3 ATP even though now we know it's more like 2.5.

 

[jay47]

wrong, the NADH from glycolysis only make 2 ATP per NADH instead of 3 ATP cuz they have to be transported into the mitochondria from the cytoplasm, its 6 not 8

I'm not so sure about that....I think that they normally make 2.5, However, assume that they make 3 in most circumstances because almost all entry level bio books round up (like Campbell's Bio). I will have to agree with Lemoncurry on this one.

Here is an explanation; I think you will find it thorough.

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.

 

[osimsDDS]

so basically eukaryotes produce 37 ATP and prokaryotes 38 ATP? damn not bad were catching up to bacteria haha...maybe one day they will figure out that glycolysis NADH's make up 2.75 ATP per NADH and well produce 37.5 ATP...

 

[arpitpatel86]

the NAD reduced in the formation of diphosphoglyceric acid will yield 3ATP for a total of ATP (since one molecule of glucose will yield 2 molecules of 1,3 disphosphoglyceric acid). However, in bringing in bringing these NADH molecules into the mitochondria, where they will join the ETC, one molecule of ATP may be used up for each of the two NADH molecules transported, so the net yield from glycolysis under aerobic condition is six atps [(4-2) + (6 -2)]

 

[Sea of ASH]

NADH produces approx 2.5 ATPs, actually (according to my biochem class last quarter), so the answer should be 7 🙂

ya according to princetion its 2.5 atp's also. this is y princeton's total atp produced varies from kaplan

so which one do we go by??????????