Free Biological Molecules MCQs with Answers
1,790 Biological Molecules MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The chapter covers water's polarity and biological roles, carbohydrates, lipids, proteins and nucleic acids, including their monomers, bonds, structures and functions. It also distinguishes RNA from DNA and explains conjugated molecules such as glycoproteins, glycolipids and nucleoproteins, which combine organic molecules with a non-protein component.
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- A. S
- B. C
- C. N
- D. O
Explanation: Explanation for this question will be added soon!
Correct answer: S- A. High molecular weight
- B. Insoluble in water
- C. Tasteless
- D. Polymers of glucose
Explanation: The correct answer is High molecular weight. Polysaccharides are large and complex carbohydrates made up of many monosaccharide units…
Correct answer: High molecular weight- A. Ester
- B. Peptide
- C. Glycosidic
- D. Phosphodiester
Explanation: The correct answer is glycosidic. Amylase is an enzyme that catalyzes the breakdown of carbohydrates, specifically starch, into simpler…
Correct answer: Glycosidic- A. Chitin
- B. Starch
- C. Cellulose
- D. Glycogen
Explanation: Chitin is the correct answer because it is a polysaccharide that contains nitrogen, specifically in its N-acetylglucosamine monomers.
Correct answer: Chitin- A. 1,4 Glycosidic Linkage
- B. 1,2 Glycosidic Linkage
- C. 1,6 Glycosidic Linkage
- D. 1,3 Glycosidic Linkage
Explanation: In a sucrose molecule, the 1 carbon of glucose is connected to the 2 carbon of fructose, so this bond is called a 1,2 glycosidic linkage.
Correct answer: 1,2 Glycosidic Linkage1386. Carbohydrates contain:
- A. Carbon, nitrogen, and potassium
- B. Carbon, hydrogen, and chlorine
- C. Carbon, nitrogen, and oxygen
- D. Carbon, hydrogen, and oxygen
Explanation: Carbohydrates, as the name suggests, contains the elements carbon , hydrogen and oxygen. A typical example would be glucose.
Correct answer: Carbon, hydrogen, and oxygen- A. Glucose (C6H12O5)
- B. Sucrose (C2H2O)
- C. Rhamnose (C6H12O5)n
- D. Lactic acid (C3H6O3)
Explanation: Lactic acid is an organic molecule. Its chemical formula is C3H6O3 Lactic acid has the same proportion of carbon, hydrogen and oxygen as…
Correct answer: Lactic acid (C3H6O3)- A. Starch
- B. Maltose
- C. Sucrose
- D. Lactose
Explanation: When sucrose is hydrolyzed, one molecule each of α D -glucose and β D fructose.
Correct answer: Sucrose- A. Lactose and Glucose
- B. Lactose and Fructose
- C. Glucose and fructose
- D. Glucose and galactose
Explanation: Sucrose, also known as table sugar, is a disaccharide that is hydrolyzed into two monosaccharides: glucose and fructose.
Correct answer: Glucose and fructose- A. Sucrose, Glucose and Fructose
- B. Maltose, Lactose and Fructose
- C. Glycogen, Sucrose and Maltose
- D. Glycogen, Cellulose and Starch
Explanation: Polysaccharides are complex long-chain carbohydrates that are formed by dehydrate synthesis or polymerization of more than 10 but…
Correct answer: Glycogen, Cellulose and Starch- A. Sucrose
- B. Lactose
- C. Maltose
- D. Amylose
Explanation: Lactose, a disaccharide composed of glucose and galactose, contains a beta-1,4-glycosidic linkage.
Correct answer: Lactose- A. Cx(H2O)x
- B. C6H12O6
- C. Cx(H2O)y
- D. Cx(HO)y
- E. Cx(H2O2)y
Explanation: Carbohydrates are the instant sources of energy in living organisms. The general carbohydrate formula is Cx(H2O)y, where x and y are…
Correct answer: Cx(H2O)y- A. 1, 4 glycosidic linkage
- B. 1, 6 glycosidic linkage
- C. 1,2 glycosidic linkage
- D. 1,3 glycosidic linkage
Explanation: Fructose and glucose combine through condensation process to form sucrose.
Correct answer: 1,2 glycosidic linkage- A. Monosaccharides
- B. Oligosaccharides
- C. Polysaccharides
- D. Carbohydrates
Explanation: The formula (CH2O)n specifically describes monosaccharides, the simplest form of carbohydrates that consist of single sugar units.
Correct answer: Monosaccharides- A. Two ionic bonds
- B. Four ionic bonds
- C. Four covalent bonds
- D. Two hydrogen bonds
Explanation: Carbon is unique in its ability to form four covalent bonds, allowing it to be the backbone of complex organic molecules.
Correct answer: Four covalent bonds- A. Oxygen
- B. Carbon
- C. Hydrogen
- D. Nitrogen
Explanation: Carbon is the second most abundant element in the human body, accounting for 18% of body weight.
Correct answer: Carbon- A. Protein
- B. Water
- C. DNA
- D. RNA
Explanation: The correct answer is RNA. In a mammalian cell, RNA makes up about 1.1% of the cell's total mass, reflecting its role in protein synthesis…
Correct answer: RNA- A. Hydroxyl group
- B. Hydrogen
- C. Water
- D. Nitrogen
Explanation: Polymers are broken down into monomers via hydrolysis reactions, in which a bond is broken, or lysed, by addition of a water molecule.
Correct answer: Water- A. Hooves
- B. Haemoglobin
- C. Enzymes
- D. Steroids
Explanation: One major class of lipids is the steroids, which have structures totally different from the other classes of lipids.
Correct answer: Steroids- A. Two covalent bonds are formed
- B. Hydrogen bond is formed
- C. Single covalent bond is formed
- D. Ionic bond is formed
Explanation: Option A is incorrect because Two covalent bonds are formed by the sharing of two electron pairs.Option B is incorrect because Hydrogen…
Correct answer: Single covalent bond is formed