How many main types of tRNA are there?
Correct answer C. 20
Topic / 73 questions
Biological Molecules MCQs
Biological Molecules MCQs are biology questions on the chemical compounds that make up living things, including carbohydrates, proteins, lipids, nucleic acids and water, and how their structure relates to function. They help MDCAT, NEET UG and medical admission candidates master this chapter, and every question gives an instant answer so you can check yourself.
- Biological Molecules 74
- Coordination and Control 72
- Biology Diagnostic 70
- Cell Structure and Function 67
- Biotechnology 65
- Reproduction 58
- Bioenergetics 55
- Circulation 50
- Inheritance 48
- Digestion 45
- Immunity 45
- Support and Movement 45
- Acellular Life (Viruses) 45
- Homeostasis 45
- Respiration and Gaseous Exchange 45
- Evolution 45
- Enzymes 45
- Cell Cycle 41
- Chromosome and DNA 40
- Biology Introduction 38
- Ecosystem 27
What percentage of the total RNA in a cell is rRNA?
Correct answer D. 80%
What is the chemical nature of most cellular secretions?
Correct answer D. Glycoproteins
Advertisement
How do non-polar organic molecules behave in water?
Correct answer B. Insoluble
In what state are animal fats at room temperature?
Correct answer C. Solids
What type of bond keeps the helical structure of proteins in place between amino acids?
Correct answer A. H bonds
How many nitrogenous base pairs are there in each turn of the DNA helix?
Correct answer D. 10
How many polypeptide chains make up an insulin molecule?
Correct answer A. 2
What percentage of a cell’s total dry weight is made up of proteins?
Correct answer B. 50%
Advertisement
Which of these is an example of almost pure cellulose?
Correct answer D. Cotton
What do starch, cellulose and glycogen yield on complete hydrolysis?
Correct answer B. Glucose
What is the valency of a carbon atom?
Correct answer D. Tetravalent
Which one is not found in fatty acids in acylglycerols?
Correct answer B. C-25
Triglyceride is also known as
Correct answer B. Neutral lipid
In esterification OH comes from
Correct answer B. Alcohol
Advertisement
How many carbon atoms are required to form a furan ring (ribofuranose)
Correct answer B. 4
Which monosaccharides are found in some bacteria and occur rarely in nature?
Correct answer C. Tetroses
Keto group is represented as
Correct answer A. CO
The trioses which are intermediate in respiration and photosynthesis are
Correct answer C. Both of these
Glycolipids and glycoproteins have structural role in the ____ matrix of animal and bacterial cell
Correct answer A. Extracellular
About Biological Molecules MCQs
This chapter introduces biochemistry, the branch of biology that studies the chemical compounds of life. Questions cover the general formula of carbohydrates Cx(H2O)y and the range of x, trioses as intermediates in respiration and photosynthesis, triglycerides, fatty acids such as oleic acid, and why lipids store about twice the energy of carbohydrates. Protein questions test primary, secondary, tertiary and quaternary structure, haemoglobin's amino acid count and peptide bonds, while water questions focus on its high specific heat.
Biological molecules form the base for later chapters on enzymes, cell biology and genetics, so this topic is heavily tested in MDCAT and NEET UG. Questions often hinge on exact numbers and structural details. Practising them helps you remember these specifics and apply them to statement-based and assertion-style questions. Many questions are lifted closely from provincial textbooks, so careful reading of the chapter pays off.
Key facts to remember
- Biochemistry is the branch of biology that studies the chemical compounds of living organisms.
- Water is the most abundant compound in living cells.
- A peptide bond forms between the carboxyl group of one amino acid and the amino group of another.
- Haemoglobin has quaternary structure, made of four polypeptide chains.
- The primary structure of a protein is the number and sequence of its amino acids.
- Triglycerides are formed from one glycerol molecule and three fatty acids.
Exams that include Biological Molecules MCQs
Pakistan
- MDCAT
- NUMS entry test
- ETEA
- Lecturer tests
India
- NEET UG
- CUET
- State TETs
Bangladesh
- Medical admission test (MBBS)
- University admission tests (DU, RU, JU)
- Government job tests
How to prepare for Biological Molecules MCQs
- Make a table of the four protein structure levels with the bonds that stabilise each and one example protein.
- Memorise key numbers such as 574 amino acids in haemoglobin and 18 carbons in oleic acid, since numerical questions are common.
- Compare carbohydrates and lipids on energy content, solubility and function to handle statement-based questions.
- Revise water's properties, high specific heat, high heat of vaporisation and polarity, and link each to its biological role.
Frequently asked questions
What are biological molecules?
Biological molecules are the chemical compounds found in living organisms. The major organic groups are carbohydrates, proteins, lipids and nucleic acids, while water and mineral salts are important inorganic components. Each has a structure suited to its role in the cell.
How many Biological Molecules MCQs are on MCQs360?
MCQs360 has 75 Biological Molecules MCQs in its MCAT Biology section, each with an instant answer. You can practise them free without registration and revise the chapter in a single focused session. Revise protein structure questions first, as they are most frequent.
Which exams ask Biological Molecules MCQs?
This chapter is heavily tested in MDCAT and other medical entry tests in Pakistan, such as ETEA. In India it is a core part of NEET UG biology, and in Bangladesh it appears in the MBBS medical admission test and university admission tests.
Why do lipids store more energy than carbohydrates?
Lipids contain more carbon-hydrogen bonds and less oxygen than carbohydrates, so they release more energy when oxidised. One gram of fat yields roughly twice the energy of one gram of carbohydrate, which makes fat an efficient long-term energy store.
Last reviewed October 2026