A cup of raw milk, after being heated in a microwave oven to

This is exactly what the ANSWER CHOICE HINGES ON..Anyone who can pick this up from the Question stem (and the choices) will never confuse this answer choice with any other..





They are quite similar to GMAT CR's just a bit tougher (what makes them BRUTAL is that the LSAT test takers are expected to solve each question in about 80 seconds).. I feel that no prep company quite replicates the subtle variations in answer choices the way the GMAT test makers do, and LSAT CR's are very similar.. I know of quite a few LSAT test takers who start practicing GMAT CR, after they have exhausted the nearly infinite Logical Reasoning questions LSAC puts out

I cannot agree with you more than sir. If we nail each one of these in LAST timings then GMAT CRs are going to be cakewalk, But IMO that would require lots n lots of work put only in verbal. we, unlike LASTer, have to deal with Quants also. I hate those "already GOOD at QUANTs" guys (just kidding "

Cheers

I hate them too , but i guess it would not be unreasonable to expect a guy coming from an engineering or business background to find Quant a cake walk. I am a MD, and have not touched quant in almost a decade, so for me it was PAIN in the last 2 months, and i have only reached a 44 on GMAT PREP ( another couple of months to go before i cross 47).. But for people like me Boosting Verbal is another way to take the overall score beyond 700 ( say take V to 40 or beyond, then i would only need Q46 to hit the 700 mark) especially if one finds Verbal concepts not all that challenging.

Today I took three extremely brutal LSAT reasoning sections timed (25 questions per section), and managed to average 39 minutes a section (LSAC gives 35 minutes a section) and my overall accuracy was around 85% (95% for the first 14 questions on each section which many experts consider more realistic GMAT difficulty)..That has done wonders for me, and i think i have improved my CR level after reading the text book for the second time and going up against LSAT sets...I hit LSAT RC's next .. Before hitting the grammar and SC books HARD to boost up my SC (Before i started CR prep i was in the 75th percentile in Verbal) ..

Hi Experts GMATNinja GMATNinjaTwo

Can you please help with analysis of argument and B/ E in detail.
Do we not have to prove that destruction of enzymes is due to ANY heat
and not necessarily the heat generated by microwave

"The argument contains causal reasoning, because the conclusion attempts to attribute a phenomenon (difference in concentration of lysozyme) to a particular cause—microwaves:

Premise: When you heat raw milk in a microwave to 50'C, it contains half of its initial concentration of lysozyme.
Premise: When you heat raw milk on the stove to 50'C, it contains nearly all of its initial concentration of lysozyme.

Conclusion: Microwaves (cause) Destroy lysozyme (effect)

As with many causal arguments, this one ignores the possibility of an alternative cause. What if the depletion of lysozyme has nothing to do with microwaves? Maybe microwaves do something else to the milk that destroys its lysozyme?

Answer choice (A) is incorrect, because it is consistent with the information in the stimulus. If heating the milk to 50'C destroys half of the lysozyme, it's possible that heating it to a boiling temperature would destroy all of it. There is no reason to believe that this would weaken the argument.

Answer choice (B) is incorrect, because the issue is not whether the lost enzymes can be replaced, but rather why they are lost in the first place.

Answer choice (C) is incorrect, because it only stands to reason that liquids heat up faster when exposed to higher temperatures. This does not explain the difference in the amount of lysozyme observed.

Answer choice (D) is incorrect, because the issue of taste has no bearing on the conclusion of the argument. The question is why microwaved milk has less lysozyme than milk exposed to conventional heat source, not whether this difference affects taste.

Answer choice (E) is the correct answer choice. If heating milk by microwave creates small zones within it that are much hotter than 50'C, then it stands to reason that these pockets will lose lysozyme at a higher rate than the rest of the milk. So, although the overall temperature reached is ultimately 50'C, some of the milk will have been exposed to much higher temperatures, which could have caused its enzymes to break down."
(https://forum.powerscore.com/lsat/viewtopic.php?t=11057)

A cup of raw milk, after being heated in a microwave oven to 50 degrees Celsius, contains half its initial concentration of a particular enzyme, lysozyme. If, however, the milk reaches that temperature through exposure to a conventional heat source of 50 degrees Celsius, it will contain nearly all of its initial concentration of the enzyme. Therefore, what destroys the enzyme is not heat but microwaves, which generate heat.

Which one of the following, if true, most seriously weakens the argument?
Analysis: weaken
microwave oven @50C --> contains 1/2 of enzyme * conventional heating @ 50
conclusion: microwave oven destroys enzyme, not heat because both the temperates are same @ 50C
But if we can prove that heat in microwave destroys the enzyme, then the conclusion will be weaken


(A) Heating raw milk in a microwave oven to a temperature of 100 degrees Celsius destroys nearly all of the lysozyme initially present in that milk. --> irrelevant: we just care about 50C

(B) Enzymes in raw milk that are destroyed through excessive heating can be replaced by adding enzymes that have been extracted from other sources. --> irrelevant: we need to compare the two condition, doesn't matter how to recover

(C) A liquid exposed to a conventional heat source of exactly 50 degrees Celsius will reach that temperature more slowly than it would if it were exposed to a conventional heat source hotter than 50 degrees Celsius. --> irrelevant: need to compare conventional to microwave, conventional to conventional comparison will not weaken the argument

(D) Milk that has been heated in a microwave oven does not taste noticeably different from milk that has been briefly heated by exposure to a conventional heat source. --> taste doesn't weaken the conclusion

(E) Heating any liquid by microwave creates small zones within it that are much hotter than the overall temperature that the liquid will ultimately reach.--> correct: matches with analysis: it's saying that localized heats > 50C in microwave destroys the enzyme

hiranmay,

My argument about why E is not strong candidate.

Option E says that some part of the liquid get much hotter than overall temperature that the liquid will reach. What causes this scenario? Microwave . It doesn't matter how microwave is causing this issue. Ultimately, microwave is the culprit. The conclusion states that microwave does something. Option E says that how microwave causes the the effect stated in the conclusion. Therefore, option E provides the explanation and mechanism how microwave causes the effect stated in the argument.

Hence, rather than making weak, option E is strengthening the conclusion by providing detailed explanation.

Please enlighten me.

Thank you.

I will try:

I think "killing my microwaves" means the direct action of microwaves. The action similar to the action of killing a living being by an arrow.
In this case, when the microwave simply generates the heat in different pockets. Finally the heat is responsible for destroying the enzymes. The question is speaking about direct action rather than the indirect action of the source.

GMATNinja
GMATNinjaTwo

In option (E), whatif the reduction in enzymes is caused by the microwaves alone and not by the "localized heat"
Any thoughts?

The question asks us to weaken the argument, not to prove that the argument is completely incorrect. So, it's enough to have an answer choice that pokes a hole in the author's reasoning.

That's exactly what (E) does. It shows that the author isn't seeing the full picture -- because small pockets of very hot liquid are created when something is heated in the microwave, then maybe the enzymes are destroyed by these pockets of heat. That's enough to weaken the argument, even if it doesn't 100% prove that the author is wrong.

I hope that helps!

A cup of raw milk, after being heated in a microwave oven to 50 degrees Celsius, contains half its initial concentration of a particular enzyme, lysozyme. If, however, the milk reaches that temperature through exposure to a conventional heat source of 50 degrees Celsius, it will contain nearly all of its initial concentration of the enzyme. Therefore, what destroys the enzyme is not heat but microwaves, which generate heat.

Which one of the following, if true, most seriously weakens the argument?

(A) Heating raw milk in a microwave oven to a temperature of 100 degrees Celsius destroys nearly all of the lysozyme initially present in that milk. - WRONG. Strengthens if at all.

(B) Enzymes in raw milk that are destroyed through excessive heating can be replaced by adding enzymes that have been extracted from other sources. - WORNG. Out of scope.

(C) A liquid exposed to a conventional heat source of exactly 50 degrees Celsius will reach that temperature more slowly than it would if it were exposed to a conventional heat source hotter than 50 degrees Celsius. - WRONG. True is real world context but nothing related to the passage.

(D) Milk that has been heated in a microwave oven does not taste noticeably different from milk that has been briefly heated by exposure to a conventional heat source. - WRONG. Irrelevant.

(E) Heating any liquid by microwave creates small zones within it that are much hotter than the overall temperature that the liquid will ultimately reach. - CORRECT. Rejected this because of blue text as it suggests that eventually Microwave is responsible for such heating. But in the latter half it mentions specifically 50 degrees Celsius beyond which the liquid itself creates the hotter zones. Though it looks causality-wise that microwave was responsible but it is actually at 50 degrees Celsius only. This eventually weakens the argument though somewhat and with little bit of unease(for me).

Answer E.

Hi experts GMATNinja KarishmaB MartyMurray DmitryFarber

(E) Heating any liquid by microwave creates small zones within it that are much hotter than the overall temperature that the liquid will ultimately reach.

I am still confused with the below chain of reasoning:
Microwave heating --> creation of small waves which have higher overall temperature than 50C --> Lysozyme concentration reduced to half

We can see that small waves are created by microwaves only so how does this weaken the argument that microwaves are not responsible?

A --> B --> C
If someone says B caused C but we knew that A caused B, ultimately, A caused C.

I rejected option E due to this thinking. I am not very clear why E is the correct one.
Please let me know what critical thing I am missing in my reasoning.

The conclusion says that not heat, but microwaves (the electromagnetic radiation) are destroying the enzyme. They wavelength or another property is such that the enzyme gets destroyed, not due to their heating action.
Option (E) says that in the microwave device, some parts get much hotter and that is destroying the enzyme, not the radiation directly.

Thanks KarishmaB

Correct me if I am wrong, is the subtle difference between "microwave" and "microwaves" playing a role here?
In a nutshell, microwave created small zones which shows heating is responsible, thus, decreased the confidence that microwaves were responsible for lysozyme loss. Do I understand this correctly?

Not exactly. A microwave can be the actual wave or a microwave oven. But in this context, "heating by microwave" just means "using microwaves to heat something." True, that would almost certainly be in a microwave oven, but the absence/presence of the letter s is not the issue.

What's important to notice here is that we don't need to show that microwaves didn't cause the reduction in lysozyme. What we need to look at is how these reductions occur. What is the mechanism? The author is saying it can't just be the heat that microwaves create, or the conventionally-heated milk would show the same loss. So they conclude that it must be the presence of microwaves themselves that is causing the problem. In other words, the author is arguing that microwaves are the DIRECT cause of the destruction, not an indirect cause (from creating heat). It would be like if someone hit you with a ball and you fell down, breaking your leg. We might argue about whether the ball broke your leg, or whether the fall (caused byt the ball) broke it. Either way, it's that person's fault for hitting you with the ball, but one version is more direct than the other.

E shows how heat could still be the issue, thus weakening the author's conclusion that microwaves themselves are the direct cause.