Biology of Bitterness Reading Answers

Dec 1, 2022

Biology of Bitterness Reading Answers have 14 questions that need to be answered in 20 minutes. Biology of Bitterness IELTS Reading Answers comprises two types of questions, namely- Choose correct letter, complete the summary. For Choose correct letter, candidates must read the passage and understand the statement provided and answer. To complete the summary, candidates must read the IELTS reading passage, identify keywords, and recognize synonyms to answer the question.

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Reading Passage Questions

To many people, grapefruit is palatable only when doused in sugar. Bitter Blockers like adenosine monophosphate could change that.

There is a reason why grapefruit juice is served in little glasses: most people don’t want to drink more than a few ounces at a time. aringin, a natural chemical compound found in grapefruit, tastes bitter. Some people like that bitterness in small doses and believe it enhances the general flavor, but others would rather avoid it altogether. So juice packagers often select grapefruit with low naringin though the compound has antioxidant properties that some nutritionists contend may help prevent cancer and arteriosclerosis.

It is possible, however, to get the goodness of grapefruit juice without the bitter taste. I found that out by participating in a test conducted at the Linguagen Corporation, a biotechnology company in Cranbury, New Jersey. Sets of two miniature white paper cups, labeled 304and 305, were placed before five people seated around a conference table. Each of us drank from one cup and then the other, cleansing our palates between tastes with water and a soda cracker. Even the smallest sip of 304 had grapefruit ‘s unmistakable bitter bite. But 305 was smoother; there was the sour taste of citrus but none of the bitterness of naringin. This juice had been treated with adenosine monophosphate, or AMP, a compound that blocks the bitterness in foods without making them less nutritious.

Taste research is a booming business these days, with scientists delving into all five basics-sweet, bitter, sour, salty, and umami, the savory taste of protein. Bitterness is of special interest to industry because of its untapped potential in food. There are thousands of bitter -tasting compounds in nature. They defend plants by warning animals away and protect animals by letting them know when a plant may be poisonous. But the system isn’t foolproof. Grapefruit and cruciferous vegetable like Brussels sprouts and kale are nutritious despite-and sometimes because of-their bitter-tasting components. Over time, many people have learned to love them, at least in small doses. “Humans are the only species that enjoys bitter taste,” says Charles Zuker, a neuroscientist at the University of California School of Medicine at San Diego. “Every other species is averse to bitter because it means bad news. But we have learned to enjoy it. We drink coffee, which is bitter, and quinine [in tonic water] too. We enjoy having that spice in our lives.” Because bitterness can be pleasing in small quantities but repellent when intense, bitter blockers like AMP could make a whole range of foods, drinks, and medicines more palatable-and therefore more profitable.

People have varying capacities for tasting bitterness, and the differences appear to be genetic. About 75 percent of people are sensitive to the taste of the bitter compounds phenylthiocarbamide and 6-n-propylthiouracil. and 25 percent are insensitive. Those who are sensitive to phenylthiocarbamide seem to be less likely than others to eat cruciferous vegetables, according to Stephen Wooding, a geneticist at the University of Utah. Some people, known as supertasters, are especially sensitive to 6-n-propylthiouraci because they have an unusually high number of taste buds. Supertasters tend to shun all kinds of bitter-tasting things, including vegetable, coffee, and dark chocolate. Perhaps as a result, they tend to be thin. They’re also less fond of alcoholic drinks, which are often slightly bitter. Dewar’s scotch, for instance, tastes somewhat sweet to most people. ” But a supertaster tastes no sweetness at all, only bitterness,” says Valerie Duffy, an associate professor of dietetics at the University of Connecticut at Storrs.

In one recent study, Duffy found that supertasters consume alcoholic beverages, on average, only two to three times a week, compared with five or six times for the average nontasters. Each taste bud, which looks like an onion, consists of 50 to 100 elongated cells running from the top of the bud to the bottom. At the top is a little clump of receptors that capture the taste molecules, known as tastants, in food and drink. The receptors function much like those for sight and smell. Once a bitter signal has been received, it is relayed via proteins known as G proteins. The G protein involved in the perception of bitterness, sweetness, and umami was identified in the early 1990s by Linguagen’s founder, Robert Margolskee, at Mount Sinai School of Medicine in New York City. Known as gustducin, the protein triggers a cascade of chemical reactions that lead to changes in ion concentrations within the cell. Ultimately, this delivers a signal to the brain that

registers as bitter. “The signaling system is like a bucket brigade,” Margolskee says. “It goes from the G protein to other proteins.”

In 2000 Zuker and others found some 30 different kinds of genes that code for bitter-taste receptors. “We knew the number would have to be large because there is such a large universe of bitter tastants,” Zuker says. Yet no matter which tastant enters the mouth or which receptor it attaches to, bitter always tastes the same to us. The only variation derives from its intensity and the ways in which it can be flavored by the sense of smell. “Taste cells are like a light switch,” Zuker says. “They are either on or off.”

Once they figured put the taste mechanism, scientists began to think of ways to interfere with it. They tried AMP, an organic compound found in breast milk and other substances, which is created as cells break down food. Amp has no bitterness of its own, but when put it in foods, Margolskee and his colleagues discovered, it attaches to bitter-taste receptors. As effective as it is, AMP may not be able to dampen every type pf bitter taste, because it probably doesn’t attach to all 30 bitter-taste receptors. So Linguagen has scaled up the hunt for other bitter blockers with a technology called high-throughput screening. Researchers start by coaxing cells in culture to activate bitter-taste receptors. Then candidate substances, culled from chemical compound libraries, are dropped onto the receptors, and scientists look for evidence of a reaction.

Tin time, some taste researchers believe, compounds like AMP will help make processed foods less unhealthy. Consider, for example, that a single cup of Campbell’s chicken noodle soup contains 850 milligrams of sodium chloride, or table salt-more than a third of the recommended daily allowance. The salt masks the bitterness created by the high temperatures used in the canning process, which cause sugars and amino acids to react. Part of the salt could be replaced by another salt, potassium chloride, which tends to be scarce in some people’s diets. Potassium chloride has a bitter aftertaste, but that could be eliminated with a dose of AMP. Bitter blockers could also be used in place of cherry or grape flavoring to take the harshness out of children’s cough syrup, and they could dampen the bitterness of antihistamines, antibiotics, certain HIV drugs, and other medications.

A number of foodmakers have already begun to experiment with AMP in their products, and other bitter blockers are being developed by rival firms such as Senomyx in La Jolla, California. In a few years, perhaps, after food companies have taken the bitterness from canned soup and TV dinners, they can set their sights on something more useful: a bitter blocker in a bottle that any of us can sprinkle on our brussels sprouts or stir into our grapefruit juice.

Solution With Explanation

Questions 1-8:
The reading Passage has seven paragraphs A-I.
Which paragraph contains the following information?
Write the correct letter A-I, in boxes 1-8 on your answer sheet.

Question 1: Experiment on bitterness conducted

Answer: B
Supporting sentence: It is possible, however, to get the goodness of grapefruit juice without the bitter taste.
Keyword: bitter taste, test conducted
Keyword Location: Paragraph B, Lines 1-3
Explanation: The author of the article took part in a test to learn how to obtain the benefits of grapefruit juice without tasting its "bitter" component. Each participant drank from a separate cup that either tasted like grapefruit or had been treated with AMP (a bitter blocker compound). It's fair to assume that information concerning "Experiment on bitterness done" is contained in Paragraph B.

Question 2: Look into the future application

Answer: I
Supporting sentence: In a few years, perhaps, after food companies have taken the bitterness from canned soup and TV dinners, they can set their sights on something more useful: a bitter blocker in a bottle that any of us can sprinkle on our brussels sprouts or stir into our grapefruit juice.
Keyword: In a few years, can set, can sprinkle on our brussels, stir into our grapefruit juice
Keyword Location: Paragraph I, Last 3 lines
Explanation: When someone says, "In a few years," they are unmistakably referring to a potential future event. The author wishes that food manufacturers might produce a bitter blocker in a bottle in the future. That can be sprinkled on foods with a bitter flavour right before we eat them. The author discusses the future use of bitter blocker in Paragraph I, thus "Paragraph I" is the right response.

Question 3: Bitterness means different information for human and animals

Answer: C
Supporting sentence: There are thousands of bitter -tasting compounds in nature.
Keyword: bitter -tasting compounds, nature
Keyword Location: Paragraph C, Lines 4
Explanation: In paragraph C, it is explained why animals and plants avoid bitter foods since they may be harmful or poisonous to them and how they protect themselves from them.

The fact that only humans have acquired a taste for items like coffee and tonic water is revealed later on in the same paragraph. In fact, humans like to consume bitter foods and drinks. Bitter items are terrible for every other creature, including humans.

Question 4: Spread process of bitterness inside of body

Answer: E
Supporting sentence: Known as gustducin, the protein triggers a cascade of chemical reactions that lead to changes in ion concentrations within the cell. Ultimately, this delivers a signal to the brain that registers as bitter.
Keyword: a cascade of chemical reactions, delivers a signal to the brain
Keyword Location: Paragraph E, Line 6
Explanation: The entire paragraph E illustrates how our bodies digest bitterness. The G-protein first detects taste molecules with its receptors before receiving the signal of bitterness and starting a series of chemical reactions. Finally, the brain receives a signal indicating that the consumed food or beverage is bitter because it alters the ion concentration within the cells. Paragraph E is the sentence that best explains how bitterness spreads throughout the body.

Question 5: How AMP blocks bitterness

Answer: G
Supporting sentence: Amp has no bitterness of its own, but when put it in foods, Margolskee and his colleagues discovered, it attaches to bitter-taste receptors.
Keyword: attaches to bitter-taste receptors
Keyword Location: Paragraph G, Lines 3-4
Explanation: Briefly stated in paragraph G, AMP binds to bitter-taste receptors despite lacking any inherent bitterness. As a result, the bitterness in meals that AMP binds to is blocked.

Question 6: Some bitterness blocker may help lower unhealthy impact

Answer: H
Supporting sentence: In time, some taste researchers believe, compounds like AMP will help make processed foods less unhealthy.
Keyword: AMP, less unhealthy
Keyword Location: Paragraph H, First 2 lines
Explanation: Researchers envision AMP (a bitter blocker) to reduce the harmful content in processed meals in the near future, according to the first sentence of paragraph H. The next sentence goes on to discuss how AMP can aid in removing potassium chloride's unpleasant taste.

Question 7: Bitterness introduced from a fruit

Answer: A
Supporting sentence: Naringin, a natural chemical compound found in grapefruit, tastes bitter.
Keyword: attaches to bitter-taste receptors
Keyword Location: Paragraph A, line 3
Explanation: The justification for people drinking grapefruit juice in miniature glasses is given at the beginning of paragraph A. Just a few ounces at a time due to the bitter flavour

Question 8: Genetic feature determines sensitivity

Answer: D
Supporting sentence: People have varying capacities for tasting bitterness, and the differences appear to be genetic.
Keyword: varying capacities, genetic
Keyword Location: Paragraph D, First line
Explanation: The first line makes a compelling argument that people's varying degrees of sensitivity to bitterness are due to genetics. Later on in the same paragraph, it is revealed that 75% of people are sensitive to bitter compounds, while the remaining 25% are insensitive.

Questions 9-12:

Question 9: The reason why grapefruit tastes bitter is because of a substance called ____ contained in it.

Answer: NARINGIN
Supporting sentence: Naringin, a natural chemical compound found in grapefruit, tastes bitter.
Keyword: Naringin, tastes bitter
Keyword Location: Paragraph A, Lines 2-3
Explanation: The chemical NARINGIN, which gives grapefruit its bitter flavor, is mentioned in Paragraph A.

Question 10: However, bitterness plays a significant role for plants. It gives a signal that certain plant is ____.

Answer: POISONOUS
Supporting sentence: There are thousands of bitter -tasting compounds in nature. They defend plants by warning animals away and protect animals by letting them know when a plant may be poisonous.
Keyword: bitter-tasting compounds, a plant may be poisonous
Keyword Location: Paragraph C, Lines 3-5
Explanation: It is clearly stated in paragraph C that it protects animals by alerting them if a plant is poisonous and defends plants by keeping harmful animals away.

Question 11: For human beings, different person carries various genetic abilities of tasting bitterness. According to a scientist at the University of Utah, ____

Answer: SUPERTASTERS
Supporting sentence: Some people, known as supertasters, are especially sensitive to 6-n-propylthiouraci because they have an unusually high number of taste buds.
Keyword: taste buds, supertasters
Keyword Location: Paragraph D, Lines 1-3, 5-7
Explanation: The specifics of how heredity affects people's levels of bitterness sensitivity are covered in length in paragraph D. The next thing we learn from the text is that certain persons are referred to as SUPERTASTERS because they have a high sensitivity to the bitter chemical 6-n-propylthiouraci.

Question 12: have exceptionally plenty of ____, which allows them to perceive bitter compounds.

Answer: TASTE BUDS
Supporting sentence: Some people, known as supertasters, are especially sensitive to 6-n-propylthiouraci because they have an unusually high number of taste buds.
Keyword: especially sensitive, unusually high number of taste buds
Keyword Location: Paragraph D, Lines 5-8
Explanation: It is mentioned in the second half of paragraph D that supertasters who are particularly sensitive to 6-n-propylthiouraci. They avoid all bitter-tasting foods because of the extremely high number of taste buds in it.

Questions 13-14:

Question 13: What is the main feature of AMP according to this passage?

offset bitter flavour in food
only exist in 304 cup
tastes like citrus
chemical reaction when meets biscuit

Answer: (A) offset bitter flavour in food
Supporting sentence: Bitter Blockers like adenosine monophosphate could change that.
Keyword: Bitter Blockers, AMP, blocks the bitterness in foods
Keyword Location: Introduction, Line 1-2
Explanation: The phrase "bitter blocker" refers to adenosine monophosphate (AMP), which is mentioned in the beginning of the article. A little further on in the essay, in paragraph B, the topic of AMP-blocking bitterness in food is explained. Therefore, the right response in this case is A.

Question 14: What is the main function of G protein?

collecting taste molecule
identifying different flavors elements
resolving large molecules
transmitting bitter signals to the brain

Answer: (D) transmitting bitter signals to the brain
Supporting sentence: The G protein involved in the perception of bitterness, sweetness, and umami was identified in the early 1990s by Linguagen’s founder, Robert Margolskee, at Mount Sinai School of Medicine in New York City.
Keyword: G protein, involved in the perception of bitterness, signal to the brain, bitter
Keyword Location: Paragraph E, Lines 7
Explanation: The Paragraph E while explaining the spread process of bitterness inside our bodies, also details the role of G protein in it. The G protein is responsible for perception of 3 basic taste flavors— bitterness, sweetness and umami, and transmits the same information to our brains via signals.

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