Biology · Chemistry

Carbohydrates and Biomolecules

986 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 carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

The polyhydroxy aldehydes are called:

  1. proteins

  2. fats

  3. carbohydrates

  4. vitamins
Reveal answer Fill a bubble to check yourself
C Correct answer
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. 
Multiple choice carbohydrates - definition and classification introduction to carbohydrates biomolecules chemistry

D-glucose & D-fructose can be differentiated by :

  1. Fehling solution

  2. Tollens reagent

  3. Benedict test
  4. $Br _2/H _2O$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$Br _2/H _2O$ being a mild oxidising agent can only oxidise aldose to carboxylic acids but cannot oxidise ketose.


As glucose contains aldehyde group it gets oxidised and converted into a carboxylic acid and is differentiate from fructose which has ketone group.

Therefore, the correct option is D.

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

Free aldehyde group can be produced on hydrolysis of which of the following compound(s)?

  1. Maltose

  2. Sucrose
  3. $\alpha$-D Glucose

  4. Lactose
Reveal answer Fill a bubble to check yourself
A,B,C,D Correct answer
Explanation

 $\alpha$-D glucose has cyclic hemiacetal structure. Hemiacetal on hydrolysis gives free aldehyde group.
Maltose, sucrose and lactose are are disacharides which on hydrolysis gives monosaccharides in which aldehyde group becomes free.
Maltose  $\displaystyle \xrightarrow { \text { hydrolysis} }$ Glucose $\displaystyle + $ glucose.
Sucrose  $\displaystyle \xrightarrow { \text { hydrolysis} }$ Glucose $\displaystyle + $ fructose.
Lactose  $\displaystyle \xrightarrow { \text { hydrolysis} }$ Glucose $\displaystyle + $ galactose.

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

Which of the following is a physical property of sugar?

  1. It is a white crystalline solid.

  2. Carbon, hydrogen, and oxygen are its constituents.
  3. It turns black when concentrated $\displaystyle { H } _{ 2 }{ SO } _{ 4 } $ reacts with it.

  4. When heated it decomposes.

  5. It decomposes readily.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Colour and appearance are physical properties.
The remaining are chemical properties which include its composition, reaction with sulphuric acid and decomposition. 

Multiple choice

What does NSC stand for?

  1. Nitrogen Standard Calculation

  2. Nonstructural Carbohydrates

  3. Nitrogen Substitute Calories

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

In dairy nutrition, NSC stands for Nonstructural Carbohydrates. These include sugars, starches, and pectins, which are highly fermentable energy sources.

Multiple choice bio-chemistry food through digestive tract absorption of food absorption parts of the digestive system: structure and function

Which of the following is the most rapidly transported monosaccharide into the bloodstream from the intestine?

  1. Mannose

  2. Glucose

  3. Galactose

  4. Fructose
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Transportation of galactose is most rapid as it attaches with sodium ion and easily dragged by the protein carries so it is very easy to transport it while glucose and fructose require energy to transport as they are transported by active transport.

So the correct option is 'Galactose'.

Multiple choice bio-chemistry absorption by roots - the processes involved osmotic relations of plant cells transport across membrane imbibition and its importance

The osmotic pressures of $0.1$ glucose and $0.1$M sucrose solutions are the same because ______________________.

  1. Both are carbohydrates

  2. These are different compounds having different molecular weights

  3. Both are present in the same concentration

  4. Glucose is reducing sugar while sucrose in non-reducing sugar
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Osmotic pressure is a colligative property, meaning it depends directly on the number of solute particles per unit volume rather than the chemical nature of the solute. Since both glucose and sucrose are non-electrolytes and present in the exact same molar concentration (0.1M), they yield the same number of particles in solution and thus exhibit identical osmotic pressures.

Multiple choice chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes
Zymase is used to catalyse the hydrolysis of glucose.

  1. True

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

Enzymes are macromolecular biological catalysts. These are highly selective catalysts greatly accelerating both the rate and specificity of metabolic reactions. All enzymes are insoluble since they exist in the colloidal state. Urease is an enzyme that catalyses the hydrolysis of urea, forming ammonia and carbon dioxide.
Zymase is used to catalyse the hydrolysis of glucose.
Zymase is an enzyme complex that catalyses the fermentation of glucose into ethanol and carbon dioxide. It occurs naturally in yeasts.

Multiple choice chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

Starch converts into maltose by the catalytic action of the enzyme:

  1. maltase

  2. zymase

  3. diastase

  4. lipase
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Starch converts into maltose by teh action of Diastase enzyme.

$\underset { starch }{ 2{ \left( { C } _{ 6 }{ H } _{ 10 }{ O } _{ 5 } \right)  } _{ n } } +n{ H } _{ 2 }O\xrightarrow [  ]{ Diastase } \underset { maltose }{ n{ C } _{ 12 }{ H } _{ 22 }{ O } _{ 11 } } $
Multiple choice bio-chemistry biological molecule lipids and their function some biomolecules lipids

Consider the following statements.
a. Cutin is a fatty acid polymer
b. Starch is composed only of glucose residues
Which of the statements given is/are correct?

  1. $1$ only
  2. $2$ only
  3. Both $1$ and $2$
  4. Neither $1$ nor $2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cutin is indeed a hydroxy fatty acid polymer that forms the plant cuticle. Starch is a polysaccharide composed exclusively of alpha-glucose monomers linked together. Both statements are correct.

Multiple choice

What is the main type of sugar found in fruits?

  1. Fructose

  2. Glucose

  3. Sucrose

  4. Maltose
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fruits primarily contain fructose, a natural sugar that is sweeter than sucrose and is metabolized differently in the body.