Carbohydrates, Proteins & Lipids MCQ Quiz - Objective Question with Answer for Carbohydrates, Proteins & Lipids - Download Free PDF

The correct answer is Protein.

Key Points

• Wool and silk fibre are obtained from animals. 
• The protein fibre of silk is composed mainly of fibroin.
• The silk fibre is drawn from the cocoon of the silkworm.
• Wool is obtained from the fleece of sheep or goat.
• It is also obtained from the hair of rabbits, yak and camels. 
• So, silk fibre is primarily made up of protein.

The correct answer is saccharin.

Key Points

• Saccharin is a zero-calorie artificial sweetener.
• It is not metabolized by the human body, which means it passes through the digestive system without being broken down.
• Saccharin is excreted in the urine unchanged.
• This characteristic makes saccharin suitable for people who need to control their calorie intake, such as those with diabetes.
• Despite its non-metabolism, saccharin is still capable of providing a sweet taste.

Additional Information

• Sucralose
  • It is a zero-calorie artificial sweetener made from sugar through a chemical process.
  • Sucralose is not fully absorbed by the body and is mostly excreted unchanged in feces, with a small amount excreted in urine.
  • It is widely used in food and beverage products.
• Aspartame
  • It is a low-calorie artificial sweetener composed of phenylalanine, aspartic acid, and methanol.
  • Aspartame is metabolized in the body into its constituent amino acids and methanol.
  • It is not excreted unchanged and is used in various diet drinks and foods.
• Alitame
  • It is a high-intensity artificial sweetener.
  • Alitame is metabolized by the body and thus not excreted unchanged in urine.
  • It is used in a limited number of food products.

The correct answer is (c), (b), (d), and (a).

Key Points

• Alitame is one of the sweetest artificial sweeteners, being approximately 2,000 times sweeter than sucrose.
• Sucralose is about 600 times sweeter than sucrose.
• Saccharin is around 300-400 times sweeter than sucrose.
• Aspartame is about 200 times sweeter than sucrose.

Additional Information

• Artificial Sweeteners:
  • These are substances used to sweeten food and beverages without the calories of sugar.
  • Commonly used as sugar substitutes in various low-calorie and sugar-free products.
  • They can be either synthetic or derived from natural substances.
• Sweetness Value:
  • A measure of how much sweeter a substance is compared to sucrose (table sugar).
  • Sucrose is the standard reference with a sweetness value of 1.
• Usage in Food Industry:
  • Artificial sweeteners are widely used in diet sodas, sugar-free candies, and other low-calorie foods.
  • They help in reducing calorie intake and managing weight.
• Health Considerations:
  • Most artificial sweeteners are considered safe when consumed within the established acceptable daily intake (ADI).
  • Some individuals may experience sensitivity or allergic reactions to certain artificial sweeteners.

The correct answer is 2000.

Key Points

• Alitame is an artificial sweetener that is used as a sugar substitute in various food and beverage products.
• It is approximately 2000 times sweeter than cane sugar (sucrose).
• This high-intensity sweetener allows for a significant reduction in the amount needed to achieve the desired sweetness.
• Alitame is known for its clean sweet taste without any bitter aftertaste, making it a preferred choice in many applications.
• It is stable under a wide range of temperatures and pH levels, which makes it versatile for use in different food processing conditions.

Additional Information

• Artificial Sweeteners:
  • They are substances used to replace sugar in foods and beverages to provide a sweet taste without the calories.
  • Common artificial sweeteners include aspartame, saccharin, sucralose, and stevia.
  • These sweeteners are often used in products aimed at weight management and for individuals with diabetes.
  • They are regulated by food safety authorities such as the FDA to ensure they are safe for consumption.
• Safety and Regulation:
  • The safety of alitame, like other artificial sweeteners, has been evaluated by various health organizations worldwide.
  • It is approved for use in several countries, although its approval status can vary.
  • Regulatory agencies establish acceptable daily intake (ADI) levels to ensure safe consumption limits.
• Applications:
  • Alitame is used in a variety of products such as carbonated drinks, desserts, dairy products, and baked goods.
  • It is particularly useful in low-calorie and sugar-free products.
• Advantages:
  • Due to its high sweetness potency, only a small amount is needed, making it cost-effective for manufacturers.
  • Alitame does not contribute to dental cavities, which is an added benefit for dental health.

The Correct answer is Sucrose.

Key Points

• Sucrose is a disaccharide composed of glucose and fructose linked by a glycosidic bond.
• It is classified as a non-reducing sugar because both of its anomeric carbons are involved in the glycosidic bond, making it incapable of reducing other substances.
• Unlike reducing sugars, sucrose does not have a free aldehyde (-CHO) or ketone (-CO) group in its structure.
• Upon hydrolysis by acid or the enzyme sucrase (invertase), sucrose breaks down into its constituent monosaccharides, glucose and fructose.
• Sucrose is found naturally in plants such as sugarcane, sugar beet, and fruits.
• It is widely used as a sweetener in the food industry.
• In laboratory tests like Benedict’s test or Fehling’s test, sucrose does not produce a positive result because it lacks reducing properties.

 Additional Information

• Glucose
  • Glucose is a monosaccharide and a reducing sugar.
  • It has a free aldehyde group, which allows it to act as a reducing agent in tests like Benedict's or Fehling's.
  • It is an important source of energy in cellular respiration.
  • It is naturally found in fruits, vegetables, and honey.
• Fructose
  • Fructose is also a monosaccharide but is a reducing sugar.
  • It contains a free ketone group, enabling it to reduce oxidizing agents.
  • Fructose is naturally found in fruits, honey, and root vegetables.
  • It is sweeter than glucose and sucrose.
• None of these
  • This option is incorrect because a non-reducing sugar is explicitly identified as sucrose.

The correct answer is Protein.

Key Points

• Wool and silk fibre are obtained from animals. 
• The protein fibre of silk is composed mainly of fibroin.
• The silk fibre is drawn from the cocoon of the silkworm.
• Wool is obtained from the fleece of sheep or goat.
• It is also obtained from the hair of rabbits, yak and camels. 
• So, silk fibre is primarily made up of protein.

The correct answer is Both A and D.

Key Points

• Hexoses, glucose, and fructose are the most common monosaccharides found in fruits and vegetables.
• Fructose is a monosaccharide, a form of sugar. Fructose, like other sugars, has four calories per gram.
• Fructose is often known as "fruit sugar" since it is found in many fruits naturally. Other plant foods that include it include honey, sugar beets, sugar cane, and vegetables.
• The main sugar in human blood is glucose. It is the human body's major source of energy and comes from the food you eat.
• Human blood transports glucose to all of the human body's cells for energy production. Diabetes is a condition in which blood sugar levels are abnormally high.​

Important Points

• Monosaccharides, often known as simple sugars, are the most basic sugar molecules (monomers) from which all carbohydrates are constructed.
• They are usually white, crystalline solids that are water-soluble. Only a few monosaccharides have a sweet flavour, despite their name (sugars).
• Disaccharides (such as sucrose and lactose) and polysaccharides are made up of monosaccharides (such as cellulose and starch).
• The common table sugar, sucrose, is a disaccharide that contains one molecule of each of the two monosaccharides D-glucose and D-fructose.  

Explanation:

Rubisco (d-ribulose 1,5-bisphosphate carboxylase/oxygenase) is responsible for the vast majority of global carbon fixation and has been claimed to be the most abundant protein on Earth.

The most abundant protein in nature is probably the chloroplast enzyme ribulose bisphosphate carboxylase/oxygenase (Fraction I protein).

• It is arguably the most important enzyme because it catalyses the carbon dioxide-fixing step in photosynthesis.
• The synthesis of this protein depends upon the interaction of nucleargenes with the genetic system located in the chloroplast, and involves the transfer of polypeptides across the chloroplast envelope by a post-translational mechanism.

The correct answer is Stevia

Key Points

• Stevia:
  • Stevia is a sugar substitute made from the leaves of the stevia plant.
  • It's about 100 to 300 times sweeter than table sugar, but it has no carbohydrates, calories, or artificial ingredients.

Additional Information

• Starch
  • Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds.
  • This polysaccharide is produced by most green plants as energy storage.
  • It is the most common carbohydrate in human diets and is contained in large amounts in staple foods like potatoes, maize (corn), rice, wheat and cassava.
  • Pure starch is a white, tasteless and odourless powder that is insoluble in cold water or alcohol. 
• Cellulose
  • A complex carbohy drate that is the chief component of the cell walls of plants, composed of a long chain of repeating glucose units. 
  • Cellulose can only be digested by bacteria, which often grow symbiotically in the guts of animals like ruminants and termites.
• Lactose 
  • Lactose is the principal   sugar (or carbohydrate) naturally found in milk and dairy. 
  • Lactose is composed of glucose and galactose, two simpler sugars used as energy directly by our body.
  • Lactase, an enzyme, splits lactose into glucose and galactose.  

The correct answer is Glucose + Glucose.

Key Points

• Maltose is a disaccharide molecule, made up of two Glucose molecules.
• A monosaccharide is the simplest form of sugar and the smallest unit of carbohydrate which can not be further divided.
• When two monosaccharides join it forms a molecule called Disaccharide.
• Maltase is an enzyme that is required for the hydrolysis of maltose molecules.

Important Points

• Some other disaccharides are:

The correct answer is Gopuram.

Key Points

• Keratin is the protein present in human nails.
• Keratin helps form hair, nails and your skin's outer layer (epidermis).
• It helps support your skin, heal wounds and keep your nails and hair healthy.
• There are 54 kinds of keratin in your body.

Additional Information 

• Melanin is a substance in your body that produces hair, eye and skin pigmentation. 
• Gelatin is a translucent, colorless, flavorless food ingredient, commonly derived from collagen taken from animal body parts.
• Suberin, cutin and lignins are complex, higher plant epidermis and periderm cell-wall macromolecules, forming a protective barrier.

• Keratin is a fibre protein. This protein is found in hair, nail, horn, wool etc.
• It also protects epithelial cells from damage or stress.

Key Points

The correct answer is ​Pyran is a cyclic organic compound, with one oxygen atom and five carbon atoms in the ring.

Key Points

• The six-membered cyclic structure of glucose is called a pyranose because it resembles the structure of a chemical compound called pyran.
• Pyran is a six-membered ring with five carbon atoms and one oxygen atom.
• In glucose, the six-membered ring forms when the hydroxyl group (-OH) on carbon 5 reacts with the aldehyde group (C=O) on carbon 1, creating a hemiacetal linkage.
• This reaction forms a ring that includes one oxygen atom and five carbon atoms, just like pyran. Hence, the glucose ring structure is termed a pyranose ring.

Important Points

• Glucose, as a carbohydrate, is a fundamental biomolecule involved in various biological processes.
• The pyranose structure of glucose represents its cyclic form, which is crucial in biochemistry for understanding how glucose behaves in cells, participates in metabolism, and forms larger polysaccharides like starch and cellulose.

The Correct Answer is: leucoplasts

Key Points

• Colourless plastids are known as leucoplasts.
• These are non-pigmented organelles found in plant cells that play a role in storing and synthesizing various compounds, such as starch, lipids, and proteins.
• Leucoplasts can be differentiated into different types based on their function, including amyloplasts (starch storage), elaioplasts (oil storage), and proteinoplasts (protein storage)                                                                                                                                                                                                     

Additional Information

• Chromoplasts are plastids found in plant cells that are responsible for synthesizing and storing pigments, such as carotenoids, which give fruits and flowers their bright colors
• Chloroplasts are organelles found in plant cells that are responsible for photosynthesis, the process by which plants convert light energy into chemical energy in the form of glucose. Chloroplasts contain chlorophyll, the pigment that gives plants their green color.
• Protoplasts are plant cells that have had their cell walls removed. They are used in research to study cell membrane functions, gene expression, and genetic engineering. Protoplasts can also be used in plant breeding and to produce new plant varieties.

The correct answer is Carbohydrates.

Key Points

• Nowadays, people are replacing artificial sugar with stevia because it has no carbohydrates.
• Stevia
  • It is a sugar substitute made from the leaves of the stevia plant. 
  • It's about 100 to 300 times sweeter than table sugar
  • It has no carbohydrates, calories, or artificial ingredients.​
  • It contains some amount of minerals, fats, and vitamins but it is not good for health.

Additional Information

• Artificial Sweeteners
  • It is a sugar substitute used in foods and drinks.
  • It does not contain any calories.
  • It can affect hormones and slow down metabolism.
• Examples of Artificial Sweeteners