New SAT Reading Practice Test 68: Paired Passages

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Two scientists present their views on corn syrup.

PASSAGE 1

Since coming to a head in 2004, the high
fructose corn syrup crisis and its role in the
emergent obesity epidemic has faced unwavering
denial from the food industry; yet the
05efforts to defend the additive on scientific
grounds have been dubious at best. We are all
familiar with the pitiful syllogism: corn syrup
comes from corn, and corn is natural; corn
syrup, therefore, is natural. However true this
10may be, it provides no proof whatsoever as
to corn syrup's safety for human consumption.
Solanine, for example, is easily extracted
from potatoes, and while harmless in smaller
amounts, once concentrated it becomes a
15potent and potentially deadly neurotoxin.
But I digress. Let us not look to the source
of corn syrup to determine its nutritional
demerit, but turn instead to its direct metabolic
effects on our bodies.
20Under ideal circumstances, the vast
majority of sugar in our blood is derived
from starch, which is broken into glucose
before being released to the bloodstream.
Glycolysis is the name applied to ten
25sequential chemical reactions that allow us
to either liberate energy from glucose, or
transform it into fats for storage in adipose
tissue. Gluconeogenesis, meanwhile, is an
opposite process in which glucose is derived
30from non-carbohydrate substances, and a
close and efficient regulation of the balance
between glycolytic and gluconeogenic
processes in response to the changing
concentrations of glucose in the blood is
35necessary for the maintenance of healthful
homeostasis.
By far the most critical point in this regulation
occurs at the third step of glycolysis: in
the hormonally-controlled phosphorylation
40of fructose-6-phospate into fructose-
1,6-bisphospate. When glucose is abundant,
pancreatic insulin induces the forward
glycolytic catalysis of this reaction, allowing
the production of fructose-1,6-bisphospate,
45which in turn is cleaved into glyceraldehyde-
3-phosphate and dihydroxyacetone phosphate.
When glucose is scarce, pancreatic
glucagon blocks glycolysis, and induces
the gluconeogenic production of fructose-
506-phosphate, which is subsequently isomerized
into glucose-6-phosphate, and released
into the blood.
The primary problem, therefore, with
deriving major amounts of dietary sugar
55directly from fructose rather than from
starch lies in the fact that the degradation of
fructose—which, upon entry into the cell,
is split immediately into dihydroxyacetone
phosphate and glyceraldehyde—completely
60bypasses the first four steps of glycolysis,
including the most critical regulatory reaction
in the entire process. Thus, how our
bodies handle the usage of fructose is utterly
dissociated from the hormonal controls
65of insulin and glucagon, which, over time,
invariably predisposes one to obesity, diabetes
mellitus, and a host of other dangerous
metabolic disorders.

PASSAGE 2

The media frenzy and public outcry
70that have surrounded the use of high fructose
corn syrup as a food additive are as
unfounded as the similarly nonsensical
indignations that erupted in response to the
advent of commercially available genetically
75modified crop seeds. Despite ongoing proof
that genetically modified crops are not only
perfectly safe for consumption, but that they
have in fact saved an estimated 600 million
people from starvation over the past two
80decades, fears and skepticism toward them
persist simply because they are popularly
perceived as "unnatural," and thus, somehow,
unhealthy.
These same misguided apprehensions
85have been at the forefront of the crusade
against high fructose corn syrup. Yet, in reality,
the process of producing corn syrup is
strikingly similar to the carbohydrate metabolism
that occurs naturally within the human
90body. First, corn starch is broken down into
glucose by bacterial amylase enzymes, and
glucose is subsequently converted to fructose
via glucose isomerase. Overall, the recipe
is hardly as sinister as its opponents would
95have us believe.
We must acknowledge, of course, that
research has identified several serious health
risks associated with the chronic overconsumption
of sugar, and perhaps of fructose
100in particular. These risks, however, are by no
means limited to foodstuffs containing high
fructose corn syrup. Depending on the formula,
corn syrup contains between 42% and
55% fructose by volume. For comparison,
105cane sugar, honey, and agave nectar—three
popular sweeteners touted as "natural", and
therefore, more healthful—contain 50%,
52%, and 85% fructose, respectively. Thus,
while it is true that fructose should be consumed
110only in moderation, the singling out
of products that contain high fructose corn
syrup is not merely insufficient action to curb
the fructose-associated obesity epidemic in
our country, it's also patently misleading to
115consumers.

1. What is the primary purpose of lines 12-15 ("Solanine . . . neurotoxin.")?

  • A. To present practical applications
  • B. To refute a particular line of thinking
  • C. To clarify an unfamiliar term
  • D. To draw attention to a harmful process

2. As used in line 16, the word "digress" most closely means

  • A. stray.
  • B. analyze.
  • C. contradict.
  • D. reexamine.

3. According to lines 37-52, bodily regulation of glucose levels is best summarized as

  • A. artificial.
  • B. dynamic.
  • C. arbitrary.
  • D. static.

4. The author of passage 1 most directly suggests that the long-term consumption of fructose will lead to

  • A. an increasingly well-regulated hormonal balance.
  • B. a significant increase in neurotoxins in the blood supply.
  • C. a greater likelihood of developing health ailments.
  • D. no significant changes to bodily processes.

5. Which option gives the best evidence for the answer to the previous question?

  • A. Lines 13-15 ("while . . . neurotoxin")
  • B. Lines 41-47 ("When . . . phosphate")
  • C. Lines 47-52 ("When . . . blood")
  • D. Lines 62-68 ("Thus . . . disorders")

6. As used in line 81, the word "persist" most closely means

  • A. persevere.
  • B. mislead.
  • C. continue.
  • D. affect.

7. The author of passage 2 most likely uses lines 102-108 ("Depending . . . respectively") in order to

  • A. demonstrate that corn syrup is especially harmful to consumers.
  • B. show that corn syrup is undeservingly singled-out for criticism.
  • C. argue that fructose is but one reason that corn syrup is maligned.
  • D. illustrate that many foodstuffs contain great quantities of sugar.

8. It can most reasonably be inferred that the two authors would disagree with those who declared a food to be healthy simply because it is

  • A. engineered.
  • B. genetically modified.
  • C. natural.
  • D. metabolized.

9. Which option gives the best evidence for the answer to the previous question?

  • A. Lines 6-12 ("We are . . . consumption") and lines 75-83 ("Despite . . . unhealthy")
  • B. Lines 16-19 ("Let . . . bodies") and lines 86-90 ("Yet . . . body")
  • C. Lines 24-28 ("Glycolysis . . . tissue") and lines 100-104 ("These . . . volume")
  • D. Lines 47-52 ("When . . . blood") and lines 90-93 ("First . . . isomerase")

10. The authors of Passage 1 and Passage 2 primarily analyze examples from what general areas to make their respective cases?

  • A. Passage 1 analyzes examples internal to the human body, and Passage 2 analyzes examples external to the human body.
  • B. Passage 1 analyzes examples external to the human body, and Passage 2 analyzes examples internal to the human body.
  • C. Both focus on examples internal to the human body.
  • D. Both focus on examples external to the human body.