Tag: biomolecules

Questions Related to biomolecules

Which sugar does not increases the calorific value?

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. Sucrose

  2. Glucose

  3. Aspartame

  4. Fructose

Show answer
Correct Option: C
Explanation:

Aspartame is artificial sugar so it does not increases the calorie intake it only induces the sweetness.


Option C is correct.

State whether the following statements are True or False:
Aldohexoses exist in $2^6$ optical forms.

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

False-Aidohexoses exist in $2^4(= 16)$ optical forms.


Aldohexoses, with four chiral centers, have $2^4$ = 16 stereoisomers.

State whether the following statements are True or False:
Raffinose is a trisaccharide. On hydrolysis, it gives three molecules of glucose.

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

False-On hydrolysis, it gives three molecules of monosaccharide units one each of glucose, fructose and galactose

State whether the following statements are True or False:
Glucose is more sweeter than fructose

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

False-Fructose is more sweeter than glucose

To separate a mixture of monosaccharides, you would use :

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. Centrifuge

  2. Chromatograph

  3. Mass spectrometer

  4. Electrolytic cell

  5. Dialysis

Show answer
Correct Option: B
Explanation:

Two-dimensional ascending chromatography has been employed to separate a mixture of monosaccharides.

The minimum number of carbon atoms that should be present in a monosaccharide is :

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. 2

  2. 3

  3. 4

  4. 6

Show answer
Correct Option: B
Explanation:

Monosaccharide is single polyhydroxy aldehyde (aldose) or ketone (ketose) units. Glucose is a single polyhydroxy aldehyde, while fructose is a single polyhydroxy ketone. A monosaccharide contains a skeleton, of carbon atoms. The minimum number of carbon atoms is three and it can go up to seven.

Carbohydrates that, on attempted hydrolysis, are not cleaved to smaller carbohydrates are called :

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. oligosaccharides

  2. polysaccharides

  3. disaccharides

  4. monosaccharides

Show answer
Correct Option: D
Explanation:

A carbohydrate that cannot be hydrolysed further to give simpler unit of polyhydroxy aldehyde or ketone is called a monosaccharide. Some common examples are glucose, fructose, ribose, etc.
Carbohydrates that yield two to ten monosaccharide units, on hydrolysis, are called oligosaccharides. They are further classified as disaccharides, trisaccharides, tetrasaccharides, etc., depending upon the number of monosaccharides, they provide on hydrolysis. Amongst these the most common are disaccharides. The two monosaccharide units obtained on hydrolysis of a disaccharide may be same or different.

Choose the incorrect statement from following:

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. Monosaccharides are optically active polyhydroxy carbonyl compounds

  2. Fructose does not reduce Fehling's solution becauese it is a ketose

  3. $\alpha$-D(+)-Glucose and $\beta$-D(+)-glucose are anomers

  4. D-Glucose and D-mannose are C-2 epimers

Show answer
Correct Option: B

Glucose and fructose are both monosaccharides.

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Glucose and fructose are both monosaccharides as they cannot be hydrolysed further to simple sugars.

Carbohydrates mix directly with blood and supply energy to the cells.

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. True

  2. False

Show answer
Correct Option: B
Explanation:
As we take carbohydrates, our body breaks them simple sugars (glucose, fructose, and galactose) which are absorbed into the bloodstream. Any glucose not needed right away gets stored in the muscles and liver in the form of glycogen.
Therefore, the given statement is wrong