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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1,790 questions · page 83 of 90
- A. Fats /cholestrol
- B. ATP
- C. Not known without screening test
- D. Ligase
Explanation: Ligase happens to be an enzyme, catalysing lipids. Since enzymes are proteins, ligase is also a protein.
Correct answer: Ligase- A. Acid
- B. Base
- C. Neutral
- D. None of these
Explanation: The following question requires the candidate to have the basic knowledge of the structue of amino acid and it's behavior in…
Correct answer: Acid- A. 25
- B. 20
- C. 19
- D. 15
Explanation: "About 170 types of amino acids have been found to occur in cells and tissues. Of these, about 25 are constituents of proteins.
Correct answer: 25- A. Primary structure
- B. Tertiary structure
- C. Secondary structure
- D. Quaternary structure
Explanation: The tertiary structure is the overall folding of the polypeptide chain, and it is determined by the interactions between the side chains…
Correct answer: Tertiary structure- A. C-N link
- B. C-O link
- C. N-H link
- D. C-H link
Explanation: Correct option A. Since peptide bond is an amide type of covalent chemical bonding formed between the alpha nitrogen of one amino acid and…
Correct answer: C-N link- A. 575
- B. 576
- C. 574
- D. 573
Explanation: Correct option: C (fact) (There are 574 amino acids in a haemoglobin molecule).A haemoglobin molecule consists of a total of 574 amino…
Correct answer: 574- A. Globular
- B. Functional
- C. Fibrous
- D. Both Options A and B are correct
Explanation: Antibodies belong to a group of globular proteins in serum or plasma; they are therefore also known as immunoglobulins.
Correct answer: Globular- A. 250
- B. 200
- C. 20
- D. 170
Explanation: The total number of amino acids that have been found in tissues and cells are 170. 20 types of amino acids make proteins.
Correct answer: 170- A. Skin
- B. Hair
- C. Nails
- D. Body fat
Explanation: Proteins are not typically present in body fat. Body fat, also known as adipose tissue, is primarily made up of adipocytes (fat cells)…
Correct answer: Body fat- A. Acid
- B. Base
- C. Neutral
- D. None of these options are correct
Explanation: Correct option is B. Based on the definition of the acidic medium, in acidic conditions the amino acid acts as a base and accepts a proton…
Correct answer: Base- A. 1
- B. 3
- C. 2
- D. 4
Explanation: Insulin is a protein made up of two polypeptide chains referred to as the A chain and the B chain.
Correct answer: 2- A. A protein
- B. Globular protein
- C. Functional protein
- D. Secretive protein
Explanation: If amino acids are formed together by peptide bonds, they form proteins. Amino acids are the building blocks of protein.
Correct answer: A protein1653. Which structure of protein gives information about the number and sequence of amino acids in it?
- A. Primary structure
- B. Secondary structure
- C. Tertiary structure
- D. Quarternary structure
Explanation: The linear sequence of amino acids within a protein is considered the primary structure of the protein.
Correct answer: Primary structure- A. Primary structure
- B. Secondary structure
- C. Tertiary structure
- D. Quaternary structure
Explanation: A protein molecule is made up of many amino acid molecules which are attached by peptide bonds.
Correct answer: Primary structure- A. Arginine
- B. Valine
- C. Glutamic acid
- D. Tryptophan
Explanation: In mitochondria UGA codon is assigned to tryptophan (Trp) instead of being a signal for translational termination.
Correct answer: Tryptophan- A. DNA ligase
- B. DNA polymerase
- C. Ribosomes
- D. RNA polymerase
Explanation: Transcription has three stages: initiation, elongation, and termination.
Correct answer: RNA polymerase1657. NAD is an example of _:
- A. Mononucleotide
- B. Dinucleotide
- C. Tri nucleotide
- D. Tetra nucleotide
Explanation: Nicotinamide adenine dinucleotide (NAD) is a cofactor central to metabolism.
Correct answer: Dinucleotide- A. Cell membrane
- B. Cytoplasm
- C. Nucleolus
- D. Lysosomes
Explanation: The nucleolus is the site of the highest RNA synthesis rate in cell nuclei giving rise to more than 60% of the entire RNA pool.
Correct answer: Nucleolus1659. A group of ribosomes attached to mRNA is known as a polysome and the attachment is controlled by:
- A. Na+ ions
- B. Mg++ ions
- C. Ca·++ ion
- D. K+ ions
Explanation: Ribosomes are composed of two subunits known as large and small, which unites to form the active ribosome during the process of protein…
Correct answer: Mg++ ions1660. NAD is an example of:
- A. Mononucleotide
- B. Dinucleotide
- C. Trinucleotide
- D. Tetranucleotide
Explanation: Nicotinamide adenine dinucleotide (NAD) is a cofactor central to metabolism.
Correct answer: Dinucleotide