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Re: It has long been known that the rate of oxidative metabolism [#permalink]
Carcass wrote:
via anaerobic glycolysis, the energy of 3,000 humans at maximum oxidative metabolic energy production.

This means that to attack a dinosaut you do need alike numbers of human. Not only one or some.

Hope this helps.

Regards


Considering this part "There are limitations, however, to this compensation. The glycogen reserves of any animal are good, at most, for only about two minutes at maximum effort, after which only the. normal oXIdative metabolic source of energy remains. With the conclusion of a burst of activity, the lactic acid level is high in the body fluids, leaving the large animal vulnerable to attack until the acid is reconverted," So, since the energy burst only within 2 mins, after that, the dino is completely vulnerable, how can it take another attack from even a very small animal??
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
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Fortunately, muscle glycogen is used only when needed and even then only in whatever quantity is necessary. Only in times of panic or during mortal combat would the entire reserves be consumed.

They say that this mechanism had limitations. And your assumption could be somehow correct. However, in the end, the explain further the scenario. Therefore, based on the information of the passage, I do not think we might assume what you said.

At least, this is what I think you meant.

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Re: It has long been known that the rate of oxidative metabolism [#permalink]
Can anyone give insight on how to accurately identify the audience of the passage?
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
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Do you mean question 26 ??
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
Carcass wrote:
Do you mean question 26 ??


Yes, for this problem.
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
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It has long been known that the rate of oxidative metabolism (the process that uses oxygen to convert food into energy) in any animal has a profound effect on its living patterns. The high metabolic rate of small animals, for example, gives them sustained power and activity per unit of weight, but at the cost of requiring constant consumption of food and water. Very large animals, with their relatively low metabolic rates, can survive well on a sporadic food supply, but can generate little metabolic energy per gram of body weight. If only oxidative metabolic rate is considered, therefore, one might assume that smaller, more active, animals could prey on larger ones, at least if they attacked in groups. Perhaps they could if it were not for anaerobic glycolysis, the great equalizer.

Anaerobic glycolysis is a process in which energy is produced, without oxygen, through the breakdown of muscle glycogen into lactic acid and adenosine triphosphate (ATP), the energy provider. The amount of energy that can be produced anaerobically is a function of the amount of glycogen present-in all vertebrates about 0.5 percent of their muscles' wet weight. Thus the anaerobic energy reserves of a vertebrate are proportional to the size of the animal. If, for example, some predators had attacked a 100-ton dinosaur, normally torpid, the dinosaur would have been able to generate almost instantaneously, via anaerobic glycolysis, the energy of 3,000 humans at maximum oxidative metabolic energy production. This explains how many large species have managed to compete with their more active neighbors: the compensation for a low oxidative metabolic rate is glycolysis.


There are limitations, however, to this compensation. The glycogen reserves of any animal are good, at most, for only about two minutes at maximum effort, after which only the normal oxidative metabolic source of energy remains. With the conclusion of a burst of activity, the lactic acid level is high in the body fluids, leaving the large animal vulnerable to attack until the acid is reconverted, via oxidative metabolism, by the liver into glucose, which is then sent (in part) back to the muscles for glycogen resynthesis. During this process the enormous energy debt that the animal has run up through anaerobic glycolysis must be repaid, a -debt that is proportionally much greater for the larger vertebrates than for the smaller ones. Whereas the tiny shrew can replace in minutes the glycogen used for maximum effort, for example, the gigantic dinosaur would have required more than three weeks. It might seem that this interminably long recovery time in a large vertebrate would prove a grave disadvantage for survival. Fortunately, muscle glycogen is used only when needed and even then only in whatever quantity is necessary. Only in times of panic or during mortal combat would the entire reserves be consumed.


This is a super tough question because you MUST have the big picture of the passage as a whole.


(A) College students in an introductory course on animal physiology

Correct for the red parts highlighted above.


(B) Historians of science investigating the discovery of anaerobic glycolysis

No historical data are shown. A phenomenon is described

(C) Graduate students with specialized training in comparative anatomy

No comparison is done in the entire passage

(D) Zoologists interested in prehistoric animals

Nope. totally wrong

(E) Biochemists doing research on oxidative metabolism

This is probably the most tricky option. However, if the biochemist wanted to perform some sort of research the passage should show some statistics or a record of the literature in this particular field in the past and perhaps future avenues of research.
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
In Q 27, "Which of the following best states the central idea of the passage?":
Why can't the answer be C)?
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
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They do not pay anything in terms of costs. The only thing that is mentioned in the passage is that the cost to maintain that process is to eat and drink way to much.

The main reason of the passage is A.

How those animals can offset with a tricky process what nature does not give them

It is all about compensation and how it unfolds or explained.

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Re: It has long been known that the rate of oxidative metabolism [#permalink]
Carcass wrote:
It has long been known that the rate of oxidative metabolism (the process that uses oxygen to convert food into energy) in any animal has a profound effect on its living patterns. The high metabolic rate of small animals, for example, gives them sustained power and activity per unit of weight, but at the cost of requiring constant consumption of food and water. Very large animals, with their relatively low metabolic rates, can survive well on a sporadic food supply, but can generate little metabolic energy per gram of body weight. If only oxidative metabolic rate is considered, therefore, one might assume that smaller, more active, animals could prey on larger ones, at least if they attacked in groups. Perhaps they could if it were not for anaerobic glycolysis, the great equalizer.

Anaerobic glycolysis is a process in which energy is produced, without oxygen, through the breakdown of muscle glycogen into lactic acid and adenosine triphosphate (ATP), the energy provider. The amount of energy that can be produced anaerobically is a function of the amount of glycogen present-in all vertebrates about 0.5 percent of their muscles' wet weight. Thus the anaerobic energy reserves of a vertebrate are proportional to the size of the animal. If, for example, some predators had attacked a 100-ton dinosaur, normally torpid, the dinosaur would have been able to generate almost instantaneously, via anaerobic glycolysis, the energy of 3,000 humans at maximum oxidative metabolic energy production. This explains how many large species have managed to compete with their more active neighbors: the compensation for a low oxidative metabolic rate is glycolysis.


There are limitations, however, to this compensation. The glycogen reserves of any animal are good, at most, for only about two minutes at maximum effort, after which only the normal oxidative metabolic source of energy remains. With the conclusion of a burst of activity, the lactic acid level is high in the body fluids, leaving the large animal vulnerable to attack until the acid is reconverted, via oxidative metabolism, by the liver into glucose, which is then sent (in part) back to the muscles for glycogen resynthesis. During this process the enormous energy debt that the animal has run up through anaerobic glycolysis must be repaid, a -debt that is proportionally much greater for the larger vertebrates than for the smaller ones. Whereas the tiny shrew can replace in minutes the glycogen used for maximum effort, for example, the gigantic dinosaur would have required more than three weeks. It might seem that this interminably long recovery time in a large vertebrate would prove a grave disadvantage for survival. Fortunately, muscle glycogen is used only when needed and even then only in whatever quantity is necessary. Only in times of panic or during mortal combat would the entire reserves be consumed.


This is a super tough question because you MUST have the big picture of the passage as a whole.


(A) College students in an introductory course on animal physiology

Correct for the red parts highlighted above.


(B) Historians of science investigating the discovery of anaerobic glycolysis

No historical data are shown. A phenomenon is described

(C) Graduate students with specialized training in comparative anatomy

No comparison is done in the entire passage

(D) Zoologists interested in prehistoric animals

Nope. totally wrong

(E) Biochemists doing research on oxidative metabolism

This is probably the most tricky option. However, if the biochemist wanted to perform some sort of research the passage should show some statistics or a record of the literature in this particular field in the past and perhaps future avenues of research.


Great answer, thank you Carcass. This is the only question I got wrong in this passage. I understand why the A is the correct answer now but would you be able to explain why E is not the right answer? I chose E because the author went into detail about the anaerobic glycolysis process as an alternative way of generating energy of oxidative metabolism, so I would think the author would address biochemist audience who may focus TOO much about oxidative metabolism but did not know enough about anaerobic. Thanks in advance
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
Can someone please explain Q25?
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
What about Q25?
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
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There are limitations, however, to this compensation. The glycogen reserves of any animal are good, at most, for only about two minutes at maximum effort, after which only the normal oxidative metabolic source of energy remains. With the conclusion of a burst of activity, the lactic acid level is high in the body fluids, leaving the large animal vulnerable to attack until the acid is reconverted, via oxidative metabolism, by the liver into glucose, which is then sent (in part) back to the muscles for glycogen resynthesis. During this process the enormous energy debt that the animal has run up through anaerobic glycolysis must be repaid, a -debt that is proportionally much greater for the larger vertebrates than for the smaller ones. Whereas the tiny shrew can replace in minutes the glycogen used for maximum effort, for example, the gigantic dinosaur would have required more than three weeks. It might seem that this interminably long recovery time in a large vertebrate would prove a grave disadvantage for survival. Fortunately, muscle glycogen is used only when needed and even then only in whatever quantity is necessary. Only in times of panic or during mortal combat would the entire reserves be consumed.


25. It can be inferred from the passage that the time required to replenish muscle glycogen following anaerobic glycolysis is determined by- which of the following factors?

I. Rate of oxidative metabolism
II. Quantity of lactic acid in the body fluids
III. Percentage of glucose that is returned to the muscles

(A) I only
(B) III only
(C) I and II only
(D) I and III only
(E) I, II, and III

From the portion off the passage above we do have:
1) the rate
2) the quantity
3) The % back to the muscles

E is the answer
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
Can anyone please explain question 23?
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
Can someone explain why Q27 E option is incorrect, is it because their activities are not mentioned , but i thought that the activities regarding survival are mentioned hence i chose E.
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
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Hey,

Yes the passage talks about the difference in the metabolic oxidative rate but this is a central idea question. We have to consider the core argument here.

In this kind of question, always ask why the author wrote the passage, what was the purpose?

Choice E talks about patterns of activity and the central idea is how large animals, with their low oxidative metabolic rate, can convert substantial amounts of glycogen into energy.

That's why A is correct.

adwaithoge wrote:
Can someone explain why Q27 E option is incorrect, is it because their activities are not mentioned , but i thought that the activities regarding survival are mentioned hence i chose E.
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
please could someone explain the last (27th ) question in detail?? especially why option E is wrong?
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
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Sir,

I have explained the same, just above.
https://gre.myprepclub.com/forum/it-has-lo ... tml#p74952

Please ask if you have any other doubts.

saurabhJ007 wrote:
please could someone explain the last (27th ) question in detail?? especially why option E is wrong?
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Re: It has long been known that the rate of oxidative metabolism [#permalink]
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