Tag: chemistry

Questions Related to chemistry

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

Which enzyme converts glucose to ethanol?

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. Diesterase

  2. Invertase

  3. Zymase

  4. Both (2) and (3)

Show answer
Correct Option: C
Explanation:

$Glucose\rightarrow Ethanol$
Zymase enzymes can do above conversion.
(catalyzes fermentation of sugar into ethanol & $CO _2$).

From the following substances, which carbohydrates has the maximum sweetness?

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. Sucrolose

  2. Saccharin

  3. Aspartme

  4. Alitame

Show answer
Correct Option: D
Explanation:

All sugars are compared relative to sucrose on the basis of sweetness. Hence, sucrose is rated one in terms of sweetness. 

Alitame is the sweetest among the following with a sweetness rating of 2000, while saccharin, aspartame, and sucralose have a rating of 400, 180, and 600 respectively

Carbohydrates contains carbon, hydrogen, and oxygen molecules.

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Carbohydrates are the biomolecules containing carbon, hydrogen, and oxygen respectively. They are also called hydrates of carbon.

Carbohydrates are ___________.

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. used to make a paper

  2. produced as an intermediate in the synthesis of proteins

  3. the polyhydroxy aldehyde or polyhydroxy ketone

  4. all of these

Show answer
Correct Option: D
Explanation:

Carbohydrates are polyhydroxy aldehydes or polyhydroxy ketone. Cellulose is a carbohydrate used to make a paper. Carbohydrates are also produced as an intermediate in the synthesis of protein.

Which of the following is not the example of carbohydrate?

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. Glucose

  2. Maltose

  3. Glycine

  4. Fructose

Show answer
Correct Option: C
Explanation:

Here Glucose, Maltose, and Fructose are carbohydrate. Glycine is not a carbohydrate. It is a protein.

The polyhydroxy aldehydes are called:

carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

  1. proteins

  2. fats

  3. carbohydrates

  4. vitamins

Show answer
Correct Option: C
Explanation:
  • Polyhydroxy aldehydes or ketones are molecules with more than one hydroxyl group $(−OH)$, and a carbonyl group $(C=O)$ either at the terminal carbon atom (aldose) or at the second carbon atom (ketose) are called carbohydrates.
  • Monosaccharides are polyhydroxy aldehydes and are called Simple Sugar, any of the basic compounds that serve as the building blocks of carbohydrates.