Tag: food and it's constituents

Questions Related to food and it's constituents

Which among the following is the most common monomer of carbohydrate?

  1. Glucose

  2. Fructose

  3. Sucrose

  4. Maltose


Correct Option: A
Explanation:

Most common monomer used in polysaccharides is glucose. For example, starch, cellulose, glycogen all are polymers derived from glucose. Plants synthesize carbohydrates as glucose or fructose and store in other form like starch. The type of linkage between glucose molecules is different in storage and structural polysaccharides. The linkage in storage polysaccharides is $\alpha$- whereas $\beta$-linkage is present between glucose molecules in structural polysaccharides.

Cellulose is a

  1. A liquid

  2. A protein

  3. A polysaccharide

  4. An amino acid


Correct Option: C
Explanation:

Plant cell is characterised by presence of a cellulosic cell wall which is dead at maturity. The cellulose is a structural polysaccharide made up of glucose molecules linked by $\beta$-glycosidic linkage.

The enzyme which hydrolyses starch to maltose is

  1. Lactase

  2. Protease

  3. Maltase

  4. Amylase


Correct Option: D
Explanation:

Hydrolases catalyse hydrolytic reactions. Some of the important hydrolases includes amylases, sucrase, lactase, maltase, protease, esterase etc. 

Amylase catalyze hydrolysis of starch (polysaccharide form of glucose) into maltose (disaccharide of glucose).

The ratio between hydrogen and oxygen in carbohydrate is

  1. $5 : 1$

  2. $4 : 3$

  3. $3 : 1$

  4. $2 : 1$


Correct Option: D
Explanation:
Monosaccharide is the simplest form of carbohydrate which is composed of carbon, hydrogen and oxygen. The basic formula of the monosaccharide is C$ _n$H$ _{2n}$O$ _n$. These are considered as simplest form of sugar. The ratio between the hydrogen and oxygen is 2:1. For example, fructose is a monosaccharide with five carbon atom, ten hydrogen and five oxygen.
So, the correct answer is option D.

${C} _{n}{H} _{2n}{O} _{n}$ is the formula of

  1. Fatty acid

  2. Fat

  3. Glycerol

  4. Carbohydrate


Correct Option: D
Explanation:

CnH2nOis a general formula of monosaccharides. Monosaccharides are the simplest carbohydrates which cannot be hydrolyzed into smaller units. They usually have 3-7 carbon atoms per molecule. They are the compounds of carbon, hydrogen, and oxygen in which hydrogen and oxygen occur in the ratio of 2:1 as in a molecule of water. Thus, they are also known as hydrates of carbon. 

A fatty acid is an unbranched chain of carbon atoms with each carbon atom forming four bonds to other atoms It has a carboxylic group at one end and and the hydrogen atom bonded to all or most carbon atoms. 
Fats are formed as a result of esterification of fatty acids with various alcohols and glycerol is one of the alcohols which forms the true fats. Its formula is C$ _3$H$ _8$O$ _3$.
Thus, the correct answer is option D. 

Which of the following is a disaccharide?

  1. Glucose

  2. Lactose

  3. Starch

  4. Galactose


Correct Option: B
Explanation:

Disaccharides are oligosaccharides which are formed by condensation of two monosaccharides. Lactose is a disaccharide. It is made up of two hexose molecules, glucose, and galactose. Lactose is also known as milk sugar because it is found in milk. It is a reducing sugar. Thus, the correct answer is B

Which of the following sugars cannot be hydrolysed further to yield simple sugars?

  1. Ribose

  2. Maltose

  3. Sucrose

  4. Lactose


Correct Option: A
Explanation:

Carbohydrates which cannot be hydrolyzed further into smaller components are called monosaccharides or simple sugar. Ribose is a sugar which cannot be hydrolyzed further as it is a smaller sugar with 5 carbon. Maltose, Sucrose, and Lactose are complex sugar which can be hydrolyzed into a smaller unit of sugars. Thus, the correct option is A.

Which one of the following is not an oligosaccharide?

  1. Insulin

  2. Maltose

  3. Sucrose

  4. Raffinose


Correct Option: A
Explanation:

Insulin is a peptide hormone which helps to maintain the blood sugar level. it is secreted by the beta cells of pancreas.

Maltose is the a disaccharide which is formed by the linkage of alpha 1,4 glucose molecules. It is digested by enzyme maltase. It acts on the glycosidic bonds of the maltose and converts into simpler compounds.
Sucrose is formed by the glycosidic linkage between glucose and fructose. The bond is formed between the between C$ _1$on the glucosyl subunit and C$ _2$ on the fructosyl unit. 

Raffinose is a trisaccharide which is made up of galactose, glucose, and fructose. The enzyme α-galactosidase hydrolyses the raffinose to  D-galactose and sucrose.
So, the correct answer is option C.

Which of the following groups contains all polysaccharides?

  1. Glycogen, sucrose and maltose

  2. Sucrose, glucose and fructose

  3. Maltose, lactose and fructose

  4. Glycogen, cellulose and starch


Correct Option: D
Explanation:

The complex carbohydrates which are formed by polymerization of a large number of monosaccharides(more than 9 ). They are also known as glycans. Sucrose, Lactose, and maltose are disaccharides. Glucose and fructose are monosaccharides. Glycogen, cellulose, and starch are polysaccharides. Thus, the correct answer is D.

Which is structural polysaccharide?

  1. Glycogen

  2. Chitin

  3. Keratin

  4. Pectin


Correct Option: B
Explanation:

Chitin is the most abundant organic substance. It is a complex carbohydrate which is found in fungal walls as a structural component. It is also called as fungal cellulose. It provides strength and elasticity. Thus, the correct answer is B.