Food Chem - Reactions of Carbohydrates

What sugar is found in DNA?

• Glucose

• Ribose

• Deoxyribose

• Fructose

Answer explanation

The sugar found in DNA is called Deoxyribose. It is a type of sugar molecule that forms the backbone of the DNA molecule. Deoxyribose is different from other sugars like Glucose, Ribose, and Fructose. It is important for the structure and function of DNA. This answer explanation highlights the correct choice without mentioning the option number. The given question asks about the sugar found in DNA, not the query. The explanation is within the word limit of 75 words.

Which macromolecule is shown?

• lipid

• protein

• nucleic acid

• carbohydrate

Answer explanation

The question asks which macromolecule is shown. The correct answer is nucleic acid. Nucleic acids are responsible for storing and transmitting genetic information. They are made up of nucleotides and are found in DNA and RNA. Lipids are a diverse group of molecules that include fats, oils, and waxes. Proteins are large, complex molecules that perform a variety of functions in the body. Carbohydrates are molecules made up of sugar units and are a major source of energy.

How would you characterize the glycosidic bond found in the disaccharide, lactose, shown here?

• alpha 1-2

• beta 1-2

• alpha 1-4

• beta 1-4

Answer explanation

The glycosidic bond found in the disaccharide lactose, shown here, is a beta 1-4 bond. This bond connects the beta form of glucose to the beta form of galactose. The beta 1-4 bond refers to the linkage between the first carbon of one sugar molecule and the fourth carbon of the other sugar molecule. This bond is commonly found in lactose, which is a milk sugar. It is important to note that the answer is beta 1-4 and does not include the option number.

Which of the following is NOT a Carbohydrate?

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which of the following reagent can be used to test for the persence of reducing sugar?

• Benedit Solution

• Schabs solution

• Benedict Solution

• Millons Reagent

Answer explanation

To test for the presence of reducing sugar, Benedict Solution can be used. Benedict Solution is a reagent that changes color in the presence of reducing sugars. It forms a red precipitate when heated with reducing sugars. This test is commonly used in laboratory settings to identify the presence of reducing sugars in various substances. It is important to note that Benedict Solution is specifically designed for this purpose and should not be confused with other reagents like Benedit Solution, Schabs solution, or Millons Reagent.

Which species is not a carbohydrate?

• lactose

• glycogen

• glycerol

• amylose

Answer explanation

Glycerol is not a carbohydrate. It is a type of alcohol that is used in various biological processes. The other options, lactose, glycogen, and amylose, are all types of carbohydrates. Glycerol is different because it does not contain the same chemical structure as carbohydrates. Therefore, it is not considered a carbohydrate.

A positive Benedict’s test is indicated by the precipitation of a brick-red solid from the blue solution. Which one of the following compounds is the brick-red solid?

• Cu2O

• CuSO4

• CuCl2

• Ag2O

Answer explanation

The brick-red solid formed in a positive Benedict’s test is Cu2O. Benedict’s test is used to detect the presence of reducing sugars. When a reducing sugar is present, it reacts with the blue Benedict’s reagent, resulting in the precipitation of a brick-red solid. Among the given options, Cu2O is the compound that forms the brick-red solid. CuSO4, CuCl2, and Ag2O do not produce a brick-red solid in the Benedict’s test.

Acid-catalyzed hydrolysis of one mole of sucrose gives one mole of glucose and one mole of fructose. Which compound(s) is (are) responsible for the positive Benedict's Test that one obtains after hydrolysis of sucrose?

• Glucose

• Fructose

• Glucose and fructose

• Sucrose

Answer explanation

The acid-catalyzed hydrolysis of sucrose produces glucose and fructose. After hydrolysis, the positive Benedict's Test indicates the presence of reducing sugars. In this case, glucose is responsible for the positive test result. The hydrolysis of sucrose breaks it down into its constituent monosaccharides, and glucose is one of them. Therefore, glucose is the correct choice for the positive Benedict's Test.

What is the function of carbohydrates in the human body?

• Carbohydrates aid in digestion.

• Carbohydrates provide energy for the body.

• Carbohydrates help in muscle growth.

• Carbohydrates regulate body temperature.

Answer explanation

Carbohydrates provide energy for the body. They are the primary source of fuel for the brain and muscles. They are broken down into glucose, which is used by cells to produce ATP, the energy currency of the body. Carbohydrates also spare protein, preventing it from being used as an energy source. While carbohydrates aid in digestion, help in muscle growth, and regulate body temperature, their main function is to provide energy.

How does the structure of a monosaccharide differ from that of a disaccharide?

• A monosaccharide is composed of two sugar molecules, while a disaccharide is a single sugar molecule.

• A monosaccharide is a single sugar molecule, while a disaccharide is composed of two monosaccharides joined together.

• A monosaccharide is a complex sugar molecule, while a disaccharide is a simple sugar molecule.

• A monosaccharide is a linear sugar molecule, while a disaccharide is a branched sugar molecule.

Answer explanation

The structure of a monosaccharide differs from that of a disaccharide because a monosaccharide is a single sugar molecule, while a disaccharide is composed of two monosaccharides joined together. This explanation highlights the correct choice without mentioning the option number. The given question asks about the difference in structure between a monosaccharide and a disaccharide, not the composition of sugar molecules. Therefore, the correct answer is that a monosaccharide is a single sugar molecule, while a disaccharide is composed of two monosaccharides joined together. The explanation is within the word limit of 75 words.