Biology · Chemistry

Carbohydrates and Biomolecules

1,073 Questions

Carbohydrates and biomolecules questions test your understanding of sugars, monosaccharides, and metabolic substrates. The topic covers food transportation in plants and the biochemical properties of sweeteners. Practicing these questions builds a strong foundation for exam preparation.

Disaccharides and monosaccharidesArtificial sweetenersGlycogen storagePlant food transportGlycoprotein hormones

Carbohydrates and Biomolecules Questions

Multiple choice

Starches can be defined as _______.

  1. monosaccharides

  2. disaccharides

  3. indigestible sacchaarides

  4. polymers of sugars
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Starches are complex carbohydrates composed of long chains of glucose units, making them polymers of sugars. They are not simple sugars like monosaccharides or disaccharides.

Multiple choice

______ Forms the rigid structure of plants.

  1. amylose

  2. cellulose

  3. pectin

  4. polysaccharides
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cellulose is a structural polysaccharide that provides rigidity to plant cell walls. It is the primary component of plant fibers.

Multiple choice

Cellulose is made up of a large number of_______ units 

  1. glucose

  2. ester
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cellulose is a natural polysaccharide consisting of a linear chain of several hundred to many thousands of beta-glucose units. It is the primary structural component of plant cell walls.

Multiple choice botany metabolism, cell respiration, and photosynthesis light dependent or hill reaction phases of photosynthesis emerson's experiments & hill's reaction

Translocation of sugar in angiosperms occur in the form of 

  1. Glucose

  2. Starch

  3. Lactose

  4. Sucrose
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Translocation is the process of movement of nutrients from leaves to other parts of plant. During the process of photosynthesis, carbohydrates (sugars) specifically sucrose is synthesized in the cytosol of cell and then translocated to other demanding parts of plant. Sucrose is complex, less reactive and energy efficient sugar so, angiosperms and other plants translocate sugar in the form of sucrose.

Multiple choice carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

Invert sugar is:

  1. a type of cane sugar

  2. optically inactive form of sugar

  3. mixture of glucose and galactose

  4. mixture of glucose and fructose in equimolar quantities
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Sucrose which is an equimolar mixture of glucose and fructose on hydrolysis brings about a change in the sign of rotation from dextro (+) to laevo (-) and the product is named as invert sugar.
Hence, invert sugar is a mixture of glucose and fructose in equimolar quantities.
Multiple choice carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

Which of the following compounds is found in abundance in nature?

  1. Fructose

  2. Glucose

  3. Starch

  4. Cellulose
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cellulose is a type of carbohydrate, containing chains of glucose rings. The cell walls, which are responsible for providing support and rigidity to the plants are made of cellulose. 


It is also the primary constituent of wood, making it the most abundant organic compound found in nature.

Hence, the correct answer is option $\text{D}$.

Multiple choice carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

Molisch reagent is used to identify following compound?

  1. Glucose

  2. Raffinose

  3. D-oxribose

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Carbohydrates undergo dehydration in the presence of sulphuric acid, giving aldehyde as a product which undergoes condensation in the presence of Molisch reagent ($\alpha-napthanol $ dissolved in ethanol) to give a purple colored compound. This forms the basis of Molisch test to detect carbohydrates. Since glucose, raffinose, and deoxyribose are all carbohydrates, they can be identified using Molisch reagent

Multiple choice carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

The reagent which may be used to distinguish between cane sugar and glucose solution is

  1. Molusch's reagent

  2. Iodine solution

  3. Baeyer's reagent

  4. Fehling's solution
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Fehling's solution is used to distinguish between reducing sugars (like glucose) and non-reducing sugars (like sucrose/cane sugar). Glucose will give a positive test (red precipitate), while sucrose will not.