Nutrition and Metabolism Practice Questions

Q: Which of the following plant components is not fermented by gastrointestinal microorganisms?

Lignin. ***Lignin*** - **Lignin** is a complex polymer found in plant cell walls that is highly resistant to degradation by digestive enzymes and microbial fermentation in the gastrointestinal tract. - Its complex, cross-linked structure makes it **non-fermentable** by the microorganisms typically present in the human gut. *Cellulose* - **Cellulose** is a major component of plant cell walls and is a type of dietary fiber that can be fermented by certain gut bacteria. - While humans lack the enzymes to digest cellulose, colonic microorganisms possess cellulases that break it down into **short-chain fatty acids (SCFAs)**. *Hemicellulose* - **Hemicellulose** is a diverse group of plant polysaccharides that are a significant source of fermentable fiber for gut microbiota. - It is readily broken down by gastrointestinal bacteria into **SCFAs** and gases, contributing to colonic health. *Pectin* - **Pectin** is a soluble dietary fiber found in fruits and vegetables, known for its gel-forming properties. - It is highly fermentable by gut microorganisms, leading to the production of **SCFAs** like butyrate, propionate, and acetate.

Q: Selenium deficiency is seen in -

Keshan disease. ***Keshan disease*** - **Keshan disease** is a form of **cardiomyopathy** caused by **selenium deficiency**, particularly prevalent in regions with selenium-poor soil. - It presents with **heart failure**, arrhythmias, and cardiac enlargement. *Wilson disease* - **Wilson disease** is a disorder of **copper metabolism**, leading to excessive copper accumulation in organs, primarily the liver and brain. - It is not related to selenium deficiency. *Acrodermatitis enteropathica* - **Acrodermatitis enteropathica** is a genetic disorder of **zinc deficiency**, characterized by dermatitis, diarrhea, and alopecia. - It does not involve selenium deficiency. *None of the options* - This option is incorrect because Keshan disease is directly linked to selenium deficiency.

Q: What is the maximum value on the glycemic index scale that classifies a food as low glycemic index?

55. ***55*** - A food is classified as having a **low glycemic index (GI)** if its GI value is **55 or less**. - The GI scale classifies foods as: **low GI (≤55), medium GI (56-69), and high GI (≥70)**. - This classification indicates that the food causes a slower and lower rise in blood glucose levels compared to high or medium GI foods. *25* - This value is well below the threshold for a low GI food and is not the maximum value for this classification. - While a food with a GI of 25 would indeed be considered low GI, the question asks for the **maximum value** that still falls within this category. *45* - This value is still within the low GI range, but it is not the maximum value for this classification. - Foods with a GI up to 55 are considered low GI. *65* - A GI value of 65 falls into the **medium glycemic index** category (GI 56-69). - Therefore, this value classifies a food as medium GI, not low GI.

Q: What is the recommended daily calcium intake for adult non-pregnant females?

1000 mg. ***1000 mg*** - The recommended daily calcium intake for adult non-pregnant females (ages 19-50) is **1000 mg** according to **WHO and international guidelines** (US RDA/NIH) to maintain bone health and prevent osteoporosis. - This is the **standard recommendation** used in most medical textbooks and international nutritional guidelines. - Adequate calcium intake supports various bodily functions, including **nerve transmission**, **muscle contraction**, and **hormone secretion**. *1200 mg* - While 1200 mg is the recommended intake for **older women (above 50-70 years)** or during **pregnancy/lactation** per some guidelines, it is generally higher than necessary for non-pregnant adult females aged 19-50. - While not harmful, this higher dose is not specifically indicated for the general non-pregnant adult female population. *600 mg* - This amount of calcium is **lower than the internationally recommended daily allowance** for adult women (though it aligns with some regional guidelines like ICMR for sedentary women). - For optimal bone health and prevention of osteoporosis, **1000 mg is the widely accepted standard** in medical education. *800 mg* - This value is **below the internationally recommended daily intake** for adult non-pregnant females, which could lead to long-term calcium deficiency. - Insufficient calcium intake can increase the risk of conditions like **osteopenia** and **osteoporosis**.

Q: Which macronutrient has the highest thermogenic effect?

Proteins. ***Proteins*** - Proteins have the **highest thermogenic effect** (also known as the **thermic effect of food** or TEF) among macronutrients, typically ranging from **20-30%** of their caloric content. - This high TEF is due to the energy required for their **digestion**, **absorption**, and **metabolism** (e.g., deamination, protein synthesis), making them more metabolically "expensive" to process than fats or carbohydrates. *Fat* - Fat has the **lowest thermogenic effect**, accounting for approximately **0-3%** of its caloric content. - This low TEF is because fats are **easily absorbed** and stored, requiring minimal energy for their processing. *Carbohydrate* - Carbohydrates have an intermediate thermogenic effect, typically ranging from **5-10%** of their caloric content. - The energy expenditure for carbohydrate metabolism involves processes like **digestion**, **absorption**, and **glucose oxidation** or conversion to glycogen. *Alcohol* - While alcohol has a relatively high thermogenic effect (**20-25%**), it is **not classified as a macronutrient** in traditional nutritional science. - The three primary macronutrients are proteins, carbohydrates, and fats. Among these, **proteins** have the highest TEF.

Q: Which of the following micronutrient deficiencies can lead to anemia?

Copper. ***Copper*** - **Copper** is essential for **iron metabolism** and red blood cell formation; its deficiency can lead to **sideroblastic anemia** (often with microcytic or normocytic features) that may be accompanied by neutropenia. - Copper is required for **ceruloplasmin** function, which is necessary for iron mobilization from stores and incorporation into hemoglobin. - It also plays a role in the function of **superoxide dismutase** and **cytochrome c oxidase**, enzymes involved in antioxidant defense and energy production. *Molybdenum* - **Molybdenum** is a cofactor for several enzymes, including **xanthine oxidase** and **sulfite oxidase**, crucial for purine metabolism and detoxification. - While essential, its deficiency does not typically lead to **anemia** in humans. *Selenium* - **Selenium** is a component of selenoproteins, such as **glutathione peroxidase**, which protect cells from oxidative damage. - Deficiency is associated with conditions like **Keshan disease** (cardiomyopathy) but not primary anemia. *Fluorine* - **Fluorine** (as fluoride) is primarily known for its role in **bone and tooth mineralization**, protecting against dental caries. - It does not directly participate in **hematopoiesis** or iron metabolism, and its deficiency is not linked to anemia.

Q: Biological value is used for the assessment of?

Protein quality. ***Protein quality*** - **Biological value (BV)** is a measure of the proportion of absorbed protein from a food that is incorporated into the body's proteins. - It specifically assesses the amount and **proportions of essential amino acids** available for protein synthesis. *Fat quality* - Fat quality is typically assessed by its **fatty acid profile** (e.g., saturated, unsaturated, trans fats) and its impact on cardiovascular health. - BV is not used to evaluate the nutritional quality or absorption of lipids. *Carbohydrate quality* - Carbohydrate quality is generally determined by factors like **fiber content**, **glycemic index**, and presence of complex vs. simple sugars. - BV does not provide information about the carbohydrate composition or metabolic effects of foods. *None of the options* - This option is incorrect because biological value is a well-established method for assessing protein quality.

Q: Deficiency of which element is specifically linked to the syndrome of growth failure, anemia, and hypogonadism?

Zinc. ***Zinc*** - **Zinc deficiency** is classically associated with **growth retardation**, **anemia**, **hypogonadism**, and impaired immune function due to its role in numerous enzymatic processes and DNA synthesis. - It plays a crucial role in **cellular growth**, development, and endocrine function, making its deficiency particularly impactful on these systems. *Calcium* - **Calcium deficiency** primarily leads to **bone demineralization** (osteoporosis or osteomalacia), tetany, and muscle cramps. - While essential for growth, it is not specifically linked to the triad of **anemia** and **hypogonadism** in the same manner as zinc. *Copper* - **Copper deficiency** can cause **anemia** (microcytic, unresponsive to iron), **neurological dysfunction** (myelopathy), and impaired immune function. - However, it is not typically associated with prominent **growth failure** and **hypogonadism** as a primary triad of symptoms. *Magnesium* - **Magnesium deficiency** can lead to **neuromuscular hyperexcitability** (tetany, spasms), cardiac arrhythmias, and fatigue. - It does not commonly present with the distinct combination of **growth failure**, **anemia**, and **hypogonadism**.

Q: What is the approximate caloric content of a large egg?

70. ***70*** - A standard large egg (approximately 50 grams) contains about **70-80 calories**. - This caloric content comes from about **6 grams of protein** and **5 grams of fat** per egg. *50* - **50 calories** is generally too low for a standard large egg. - This number might be seen in very small eggs or if only specific components (like egg whites) are considered. *60* - While closer, **60 calories** is still slightly on the lower side for an average large egg. - Caloric content can vary slightly based on egg size, but 60 is typically less than expected for a whole large egg. *80* - **80 calories** is a plausible estimate for a large egg, and some large eggs can indeed reach this amount. - However, when considering the average, **70 calories** is often cited as a more precise and common approximation.

Q: Which of the following protein sources has the lowest biological value?

Gelatin. ***Gelatin*** - Gelatin is derived from collagen and is notably deficient in several **essential amino acids**, particularly **tryptophan**. - Its incomplete amino acid profile gives it a very **low biological value**, meaning it's poorly utilized by the body for protein synthesis. *Lactalbumin* - Lactalbumin is a **whey protein** found in milk, known for its **high biological value**. - It contains a **complete profile of essential amino acids** and is easily digestible. *Albumin* - Albumin, typically referring to **egg albumin** (egg white protein) or **serum albumin**, has an **excellent biological value**. - It is often used as a reference protein due to its well-balanced and **complete amino acid composition**. *Cashewnut protein* - While nuts like cashews provide protein, they generally have a **moderate to high biological value**, though typically not as high as animal proteins. - Cashew protein contains a good range of amino acids but might be slightly limited in one or two essential amino acids compared to a reference like egg or whey.

Question 1

Which of the following plant components is not fermented by gastrointestinal microorganisms?

Accepted Answer

Lignin

Answer

Cellulose

Answer

Hemicellulose

Answer

Pectin

Question 2

Selenium deficiency is seen in -

Accepted Answer

Keshan disease

Answer

Wilson disease

Answer

Acrodermatitis enteropathica

Answer

None of the options

Question 3

What is the maximum value on the glycemic index scale that classifies a food as low glycemic index?

Accepted Answer

55

Answer

25

Answer

45

Answer

65

Question 4

What is the recommended daily calcium intake for adult non-pregnant females?

Accepted Answer

1000 mg

Answer

1200 mg

Answer

600 mg

Answer

800 mg

Question 5

Which macronutrient has the highest thermogenic effect?

Accepted Answer

Proteins

Answer

Fat

Answer

Carbohydrate

Answer

Alcohol

Question 6

Which of the following micronutrient deficiencies can lead to anemia?

Accepted Answer

Copper

Answer

Molybdenum

Answer

Fluorine

Answer

Selenium

Question 7

Biological value is used for the assessment of?

Accepted Answer

Protein quality

Answer

Fat quality

Answer

Carbohydrate quality

Answer

None of the options

Question 8

Deficiency of which element is specifically linked to the syndrome of growth failure, anemia, and hypogonadism?

Accepted Answer

Zinc

Answer

Calcium

Answer

Copper

Answer

Magnesium

Question 9

What is the approximate caloric content of a large egg?

Accepted Answer

70

Answer

50

Answer

60

Answer

80

Question 10

Which of the following protein sources has the lowest biological value?

Accepted Answer

Gelatin

Answer

Albumin

Answer

Cashewnut protein

Answer

Lactalbumin

Nutrition and Metabolism — MCQs

Nutrition and Metabolism — MCQs

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