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

What are carbohydrates?

  1. Aldehydic and ketonic derivatives.

  2. Polyhyrdroxy compounds.

  3. Optically active substances and hydrates of carbon.

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

Carbohydrates are polyhydroxy aldehydes and ketones. They have two functional groups alcohol and either aldehyde or ketone. Most common carbohydrates are compounds of carbon, hydrogen and oxygen where hydrogen and oxygen occur in the ration of 2:1 like water. Hence, carbohydrates are also called as hydrates of carbon. Carbohydrates have asymmetric carbon atoms, hence, carbohydrates are optically active and rotate the plane of polarised light .

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

The molecule of biological kingdom most abundant on earth is ...................... with ....................... monomers.

  1. Cellulose, glucose

  2. Starch, glucose

  3. Glycogen, amylose

  4. Actin, amylopectin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cellulose is the most abundant organic polymer on earth. Cellulose is an important structural component of the primary cell wall of green plants. Glucose is one of the primary molecules, which serve as energy sources for plants and animals. It is the most important simple sugar in human metabolism. Cellulose can be broken down chemically into its glucose units by treating it with concentrated acids at high temperature.

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

Carbohydrates, the most abundant biomolecules on earth, are produced by

  1. All bacteria, fungi and algae.

  2. Fungi, algae and green plant cells.

  3. Some bacteria, algae and green plant cells.

  4. Viruses, fungi and bacteria.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Carbohydrates are the most abundant bimolecules found on the surface of the earth. This is so because every year plants and alga through the process of photosynthesis converts more than 100 billion metric tones of carbondioxide and water to cellulose and other products for use by the plants. 

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

Carbohydrates which cannot be further hydrolysed into simple form are

  1. Monosaccharides

  2. Disaccharides

  3. Oligosaccharides

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

Simple carbohydrates are generally soluble sugars. Simpler carbohydrates are of two types Monosaccharides and Oligosaccharides. Monosaccharides are monomer sugars which cannot be hydrolysed further into smaller units, e.g., trioses, tetroses, pentoses, hexoses and heptoses. Oligosaccharides are made up of a few units of monosaccharides.

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

The cell wall of plants is made up of cellulose, which is

  1. A lipid

  2. A protein

  3. A polysaccharide

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

In the primary plant cell wall, the major carbohydrates are cellulose, hemicellulose and pectin. The cellulose microfibrils are linked via hemicellulosic tethers to form the cellulose-hemicellulose network, which is embedded in the pectin matrix. The most common hemicellulose in the primary cell wall is xyloglucan.

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

The bonds present between two carbohydrates molecule is

  1. Glycosidic

  2. Hydrogen bond

  3. Phosphodiester

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

The bonds present between two carbohydrate molecules is glycosidic. A glycosidic bond is a type of covalent bond that joins a carbohydrate molecule to another group, which may or may not be another carbohydrate. A glycosidic bond is formed between the hemiacetal or hemiketal group of a saccharide and the hydroxyl group of some compound such as an alcohol. A substance containing a glycosidic bond is a glycoside.

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

Which of the following is sweet in taste but is not a sugar?

  1. Starch

  2. Saccharine

  3. Lactose

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

Sweet tasting carbohydrates are called sugars, e.g., glucose and fructose. Starch is a storage polymer of glucose and is tasteless till it is broken down into monomer glucose molecule. Lactose is milk sugar. Proteins are polymers of amino acids which are tasteless except for some like aspartic acid. Saccharine is an artificial sweetener. Saccharin is more sweet than common table sugar or sucrose but has a bitter after taste.

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

................... is not a carbohydrate.

  1. Starch

  2. Glycogen

  3. Wax

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

Glucose is a monosaccharide carbohydrate. Glycogen is an important storage polysaccharide in animals like starch in plants. Glycogen and starch are homopolysaccharides made up of glucose units only. Glycogen is stored in liver and muscles in animals including humans. Starch is usually stored in endosperm and cotyledons of seeds. Waxes are a type of lipids.

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

Carbohydrates, the most abundant biomolecules on Earth, are produced by

  1. Some bacteria, algae and green plant cells

  2. All bacteria, fungi and algae

  3. Fungi, algae and green plant cells

  4. Viruses, fungi and bacteria
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Carbohydrates are the most abundant bimolecules found on the face of the earth. This is so because every year plants and alga through the process of photosynthesis converts more than 100 billion metric tones of $CO _2$ and $H _2O$ to cellulose and other products for use by the plants.

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

Carbohydrates are stored in mammals as

  1. Glucose in liver.

  2. Glycogen in muscles and spleen.

  3. Lactic acid in muscles.

  4. Glycogen in liver and muscles.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Excess glucose is stored as starch or glycogen. Starch is storage polysaccharide in plants. Glycogen is storage polysaccharide in animals. In animals, including humans, glycogen is stored in two locations: muscles and liver.

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

In which one of the following groups, all the three are examples of polysaccharides :

  1. Starch, Glycogen, Cellulose

  2. Sucrose, Maltose, Glucose

  3. Glucose, Fructose, lactose

  4. Galactose, Starch, Sucrose
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Answer is option A i.e. "Starch, Glycogen, Cellulose"
Poysaccharides are carbohydrate polymers (e.g. starch, cellulose, or glycogen) which are made up of more than 10 sub-units of monosaccharide molecules join together.
Starch, glycogen and cellulose are polysaccharides of glucose. Maltose, sucrose and lactose are disaccharides, while, fructose and galactose are monosaccharides.

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

The energy produced by 1g of carbohydrate is 

  1. 2.0 kcal

  2. 4.2 kcal

  3. 7 kcal

  4. 9.4 kcal
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Carbohydrates, proteins and fats in the foods provide energy for the body functions and physical activities. They, however, do not have same energy content. The following is the energy-content by respective nutrients:
1 gram of carbohydrates- 4 kcal
1 gram of protein- 4 kcal
1 gram of fats- 9 kcal
Therefore, the correct answer is option B.