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 botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

The term glycocalyx is used for

  1. Cell wall of bacteria

  2. Bacterial cell glyco-engineered to possess N-glycosylated proteins

  3. A layer surrounding cell wall of bacteria

  4. A layer present between cell wall and cell membrane of bacteria
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Glycocalyx or pericellular matrix is a carbohydrate-enriched coating of glycoprotein and a glycolipid that covers the cell membranes of few bacteria, epithelial cells and other cells. 
  • It is mainly used in the recognition of the cell (distinguish between healthy and diseased cells) and also regulates the endothelial vascular tissues.
  • So, the correct answer is 'A layer present between cell wall and membrane of bacteria'.
Multiple choice biology coordination in life processes experiments on digestive enzymes role of receptors in the mouth types of teeth

If you chew on a piece of bread long enough, it will begin to taste sweet because

  1. maltase is breaking down maltose

  2. lipases are forming fatty acids

  3. amylase is breaking down starches to disaccharides

  4. disaccharides are forming glucose.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When you chew a piece of bread long enough, it will begin to taste sweet because amylase breaks down the starch to disaccharides.  

So the correct option is C.

Multiple choice chemistry chemical kinetics dependence of reaction rate on concentration of reactants order of reactions factors influencing rate of a reaction

The inversion of cane sugar to produce glucose and fructose is represented by the reaction
     ${ C } _{ 12 }{ H } _{ 22 }{ O } _{ 11 }+{ H } _{ 2 }O\quad \xrightarrow { { H }^{ + } } { C } _{ 6 }{ H } _{ 12 }{ O } _{ 6 }+{ C } _{ 6 }{ H } _{ 12 }{ O } _{ 6 }$
The reaction is:

  1. second order

  2. unimolecular

  3. pseudo uni-molecular

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

Inversion of Cane Sugar to produce glucose and fructose is a Pseudo uni-molecular Reaction.

Here the rate of reaction is made first order by changing the concentration of sucrose ($C _{12}H _{22}O _{11}$).

Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Choose the correct answer from the alternatives given.
Glucose ($C _6H _{12}O _6$) can exist as both an open chain form and a dosed ring form Earlier, it was thought that glucose occurs in the closed ring form What possible  difference between these forms would give scientists a clue that the open chain form was not present

  1. Only open chain forms can undergo condensation, which does not occur with glucose

  2. An open chain presents ends with functional groups (in this case aldehyde), and glucose failed to undergo typical aldehyde reactions, a phenomenon that could be explained by having no end functional group in a ring structure

  3. Because glucose is solid at room temperature, it must have saturated hydrocarbon chains

  4. Glucose could not be denatured so it must be a tight chain
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Glucose (C$ _{6}$H$ _{12}$O$ _{6}$) is the essential constituent of human blood and is a simple sugar component of carbohydrates. It exists in both the open chain structure and closed cyclic ring form. The open chain structure has a straight chain of six carbon atoms with the presence of an aldehyde group at its end but it fails to undergo aldehydic reactions. This is because the glucose ring is not very stable and can be easily broken by strong reagents like HCN to give the intermediate aldehyde form which reacts with them just like an aldehyde. But weak reagents like NH$ _{3}$ are unable to open the chain and cannot react with it. This explains the inability of glucose to form aldehyde and ammonia. So, the correct option is "an open chain present ends with functional groups (in this case aldehyde), and glucose failed to undergo typical aldehyde reactions, a phenomenon that could be explained by having no end functional group in a ring structure".

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

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

  1. Glucose

  2. Fructose

  3. Sucrose

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

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

The enzyme which hydrolyses starch to maltose is

  1. Lactase

  2. Protease

  3. Maltase

  4. Amylase
Reveal answer Fill a bubble to check yourself
D Correct answer
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).

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

Which of the following is a disaccharide?

  1. Glucose

  2. Lactose

  3. Starch

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

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

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

  1. Ribose

  2. Maltose

  3. Sucrose

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

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

Which one of the following is not an oligosaccharide?

  1. Insulin

  2. Maltose

  3. Sucrose

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

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

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
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

Which is structural polysaccharide?

  1. Glycogen

  2. Chitin

  3. Keratin

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

Multiple choice biology food and it's constituents energy giving food carbohydrate and its test biological molecules

Select the correct answer from the following statemets
1. Cutin is fatty acid polymer
2. Starch is glucose polymer
3. Sucrose is monosaccharide
4. Maltose is polymer of fructose.

  1. 1, 2, 3 are correct

  2. 1 and 2 are correct

  3. 2 and 4 are correct

  4. 1 and 3 are correct
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cutin is a polymer of glycerol and certain types of fatty acids. It is an integral part of the cuticle of the leaf. 

Starch is formed by a-1,4 linkages between two glucose unit which is broken down during its digestion. It exist in two forms known as amylose and amylopectin. Amylose is a linear poly-D-glucose in which the monosaccharides are connected by alpha 1, 4 linkages. Amylopectin is has alpha 1, 4-glycosidic linkages with side chain branching of alpha 1,6 linkage.
Sucrose is a disaccharide formed by the glycosidic linkage between glucose and fructose. It can be broken into glucose and fructose by enzyme sucrase.
Maltose is a disaccharide formed by the glycosidic linkage between glucose monomers. It can be hydrolysed to glucose by enzyme maltase.
So, the correct answer is option B.