General Science: Biology Quiz (Biomolecules)

Instructions:

1. This quiz contains 20 multiple-choice questions.
2. Select the most appropriate option for each question.
3. After selecting an option, click on "NEXT" to move to the next question.
4. Once you have completed the test, you will see your score and can review your answers.

Result:

1/20

Which of the following is a monosaccharide?

Sucrose

Maltose

Starch

Glucose

Glucose is a monosaccharide, which means it cannot be hydrolyzed into simpler sugar units. It is the most abundant monosaccharide and serves as an essential energy source for living organisms.

2/20

Which type of biomolecule is primarily involved in forming the structural framework of cells?

Proteins

Lipids

Carbohydrates

Nucleic acids

Carbohydrates, such as cellulose in plants, form the structural framework of cells. They provide rigidity and strength to cell walls, making them crucial for maintaining the shape and integrity of cells.

3/20

Which process is used to prepare glucose from sucrose?

Oxidation

Fermentation

Hydrolysis

Polymerization

Glucose is prepared from sucrose through hydrolysis, which involves breaking the glycosidic bond between glucose and fructose units using water and an acid or enzyme catalyst.

4/20

What is the general formula for carbohydrates?

Cx(H2O)x

Cx(H2O)2x

Cx(H2O)y

Cx(HO2)y

The general formula for carbohydrates is Cx(H2O)y. This reflects their composition as hydrates of carbon, although not all compounds fitting this formula are classified as carbohydrates.

5/20

Which of the following is a disaccharide?

Glucose

Lactose

Starch

Cellulose

Lactose is a disaccharide composed of glucose and galactose units. It is commonly found in milk and is known as milk sugar. Disaccharides yield two monosaccharides upon hydrolysis.

6/20

What distinguishes a reducing sugar from a non-reducing sugar?

Presence of a hydroxyl group

Ability to reduce Fehling's solution

Formation of glycosidic bonds

Presence of a carboxyl group

Reducing sugars can reduce Fehling's solution and Tollens' reagent due to their free aldehyde or ketone groups. These include all monosaccharides and some disaccharides like maltose and lactose.

7/20

Which component of starch is water-soluble?

Cellulose

Glycogen

Amylose

Amylopectin

Amylose is the water-soluble component of starch. It is a linear polymer of glucose units linked by α-1,4-glycosidic bonds and constitutes about 15-20% of starch.

8/20

Which type of linkage connects monosaccharides in polysaccharides?

Peptide linkage

Ester linkage

Glycosidic linkage

Phosphodiester linkage

Monosaccharides in polysaccharides are connected by glycosidic linkages, formed through the loss of a water molecule. These linkages create the long chains of monosaccharide units found in polysaccharides like starch and cellulose.

9/20

Which of the following is not a carbohydrate?

Glucose

Fructose

Acetic acid

Sucrose

Acetic acid is not a carbohydrate despite fitting the general formula Cx(H2O)y. Carbohydrates are defined as polyhydroxy aldehydes or ketones or compounds that yield such units upon hydrolysis, which acetic acid does not.

10/20

Which carbohydrate is also known as milk sugar?

Glucose

Sucrose

Fructose

Lactose

Lactose is known as milk sugar because it is the primary sugar found in milk. It is a disaccharide composed of glucose and galactose units linked by a β-1,4-glycosidic bond.

11/20

What is the common name for the sugar present in fruits?

Glucose

Sucrose

Fructose

Lactose

Fructose, also known as fruit sugar, is found in many fruits and honey. It is a monosaccharide and is known for its high sweetness compared to glucose and sucrose.

12/20

Which polysaccharide is the primary storage form of energy in plants?

Cellulose

Starch

Glycogen

Chitin

Starch is the primary storage form of energy in plants. It is composed of amylose and amylopectin and can be broken down into glucose units for energy during periods of low photosynthesis.

13/20

Which molecule serves as the primary storage form of energy in animals?

Cellulose

Starch

Glycogen

Chitin

Glycogen is the primary storage form of energy in animals. It is a highly branched polysaccharide stored in the liver and muscles, where it can be rapidly mobilized to meet energy demands.

14/20

Which of the following is a structural carbohydrate in plants?

Starch

Glycogen

Chitin

Cellulose

Cellulose is a structural carbohydrate in plants, forming the primary component of cell walls. It is a linear polymer of β-glucose units linked by β-1,4-glycosidic bonds, providing rigidity and strength to the plant structure.

15/20

Which disaccharide is commonly found in sugar cane and sugar beets?

Lactose

Sucrose

Maltose

Fructose

Sucrose, commonly known as table sugar, is a disaccharide found in sugar cane and sugar beets. It consists of glucose and fructose units and is widely used as a sweetener in foods and beverages.

16/20

Which type of reaction forms a glycosidic bond?

Oxidation

Dehydration

Reduction

Hydrolysis

A glycosidic bond is formed through a dehydration reaction, where a water molecule is released as a hydroxyl group from one monosaccharide and a hydrogen atom from another combine. This forms a bond between the sugar units.

17/20

Which type of biomolecule includes enzymes?

Carbohydrates

Lipids

Proteins

Nucleic acids

Proteins include enzymes, which are catalysts that speed up biochemical reactions in living organisms. Enzymes are highly specific to their substrates and play crucial roles in metabolism and other cellular processes.

18/20

Which monosaccharide is the primary energy source for the brain?

Fructose

Glucose

Galactose

Ribose

Glucose is the primary energy source for the brain. It is essential for brain function, as neurons rely heavily on glucose for energy and cannot efficiently use other forms of energy.

19/20

Which type of polysaccharide is primarily found in the exoskeletons of arthropods?

Cellulose

Starch

Glycogen

Chitin

Chitin is a polysaccharide found in the exoskeletons of arthropods, such as insects and crustaceans. It is similar to cellulose but contains nitrogen, making it a strong and flexible material.

20/20

Which carbohydrate can be directly used by cells for energy?

Starch

Glycogen

Glucose

Sucrose

Glucose can be directly used by cells for energy. It is metabolized through glycolysis and the citric acid cycle to produce ATP, the primary energy currency of cells.

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