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Certain vegetables and fruits contain plant pigments called carotenoids that are metabolized in the body to produce Vitamin A. Lack of Vitamin A causes an estimated 250,000 to 500,000 children worldwide to become blind every year. An approach to reducing blindness and other childhood health problems resulting from this deficiency is to use genetic engineering of rice- -a food staple in developing countries and economically disadvantaged regions of the world \(-\) so that rice becomes a dietary source of Vitamin A. For example, a strain known as Golden Rice has been genetically engineered so that it can produce and store carotenoids such as \(\beta\) -carotene (which helps give carrots and squash their yellow-orange color). One type of Golden Rice contains approximately 30 micrograms of carotenoids (81\% \beta-carotene, 16\% \alpha- carotene, and 3\% \beta-cryptoxanthin) per gram of uncooked rice. A study has reported that when a person eats Golden Rice, their body metabolizes 1 microgram of Vitamin A for every 3.8 micrograms of \beta-carotene they consume. (a) It is recommended that children between 1 and 3 years of age should get 300 micrograms of Vitamin A per day. Considering only the metabolism of \(\beta\) -carotene given above, how many grams of Golden Rice would a child have to eat in order to obtain this much Vitamin A? Does this seem like a reasonable amount of rice to eat in one day, if one cup of cooked rice is approximately 175 g? (b) \(\alpha\) -carotene and \(\beta\) -cryptoxanthin can also be converted into Vitamin \(A\), but when compared to \beta-carotene, it takes twice as much of each of these compounds to produce one unit of Vitamin A. Considering all of the carotenoids in Golden Rice as potential sources of Vitamin A, how many grams of Golden Rice would a three-year-old child have to eat in order to obtain the recommended daily amount of Vitamin A? (c) Some individuals are not convinced that genetically modified foods are safe to grow or to eat. What kinds of risks or uncertainties are cited by these individuals? What kinds of measures are taken by farmers and suppliers of genetically modified seeds to minimize these risks? (d) Some people do not believe that Golden Rice is a practical, viable solution to Vitamin A deficiency around the world. Summarize the major arguments for and against production and distribution of Golden Rice.

Step by step solution

01

Calculate Vitamin A from Beta-Carotene

First find the amount of beta-carotene in each gram of Golden Rice. This can be done since 81% of the carotenoids in Golden Rice are beta-carotene. So multiply 30 micrograms by 0.81 to get 24.3 micrograms of beta-carotene per gram of rice. Then, because the body metabolizes 1 microgram of Vitamin A for every 3.8 micrograms of beta-carotene, divide 24.3 by 3.8 to find the amount of Vitamin A per gram of rice which is about 6.4 micrograms. Then, divide the recommended daily amount of Vitamin A (300 micrograms) by the amount of Vitamin A per gram of rice to find the amount of rice one would need to eat. The result is approximately 47 grams of rice.

02

Include Alpha-carotene and Beta-Cryptoxanthin in the Calculation

For the second part of the problem, note that 16% of the carotenoids are alpha-carotene (30 * 0.16 = 4.8 micrograms) and 3% are beta-cryptoxanthin (30 * 0.03 = 0.9 micrograms). Given that it takes twice as much of these compounds to produce one unit of Vitamin A, divide these amounts by 2 to get the Vitamin A contribution from these two sources: 2.4 micrograms from alpha-carotene and 0.45 micrograms from beta-cryptoxanthin. Summing up these three sources, we get approximately 9.25 micrograms of Vitamin A per gram of Golden Rice. Dividing the required daily intake (300 micrograms) by this sum gives the total amount of Golden Rice the child would need to eat, which is approximately 32.43 grams.

03

Discuss Risks of Genetically Modified Foods

The answer to this part of the question will depend on background research. Common risks cited by individuals regarding genetically modified foods might include potential health effects, effects on the environment, and issues around regulation and labeling.

04

Evaluate the Golden Rice Solution

Discussing the effectiveness of Golden Rice as a solution to Vitamin A deficiency needs to consider a variety of factors. This might include cost-effectiveness, distribution challenges, cultural eating practices, and alternative solutions.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Carotenoids Metabolism

Carotenoids are natural pigments found in plants that not only give fruits and vegetables their vibrant colors but also play a crucial role in human health. When ingested, some carotenoids, such as \beta-carotene, \(\alpha\)-carotene, and \(\beta\)-cryptoxanthin are metabolized into vitamin A. This process is essential because vitamin A is a vital nutrient responsible for maintaining vision, skin health, and supporting the immune system.

When we consume foods like Golden Rice, our body converts these carotenoids into vitamin A. To understand how much vitamin A we get from Golden Rice, simple calculations are necessary. For instance, from \(\beta\)-carotene, 3.8 micrograms yields 1 microgram of vitamin A, which is essential for dietary planning, especially in populations susceptible to vitamin A deficiency. By integrating carotenoids into staple foods, we can effectively combat this deficiency on a larger scale.

Genetically Modified Foods

Genetically modified (GM) foods are created through a process where the DNA of an organism is altered to express desired traits. For example, Golden Rice is genetically engineered to produce carotenoids, aiming to alleviate vitamin A deficiency. There are many potential benefits of GM foods, including improved nutrition, increased yields, and resistance to pests and diseases.

However, there also arise concerns regarding the safety of consuming GM foods and their impact on the environment. Critics worry about the possibility of allergenicity, transfer of antibiotic resistance markers, and unintended effects on wildlife. Despite stringent regulation and testing designed to address these risks, the debate over GM food safety continues. Measures such as controlled field trials, monitoring for environmental impacts, and post-approval health surveillance are undertaken to minimize risks associated with GM crops.

Biofortification in Rice

Biofortification is the process of increasing the nutritional value of crops through conventional breeding or genetic engineering. It targets staple crops in areas where dietary deficiencies are common. Golden Rice is one of the most well-known biofortified foods, engineered to express genes that enable the production of carotenoids in the edible parts of rice.

The development of biofortified crops like Golden Rice is a strategic effort to address micronutrient malnutrition, also known as 'hidden hunger'. Biofortification offers a sustainable and cost-effective method of delivering essential nutrients, as it does not require extensive changes to existing agricultural practices or dietary habits. However, it's crucial to consider factors like bioavailability, the stability of the added nutrients, and acceptance by local communities to ensure the success of biofortified foods like Golden Rice in improving public health.