Biology · Chemistry

Biomolecules and Enzymes

1,432 Questions

This topic focuses on biomolecules, specifically proteins, enzymes, and amino acids. It includes questions on enzyme structures, protein folding, and catalysis. These concepts are crucial for medical and biology competitive exams.

Enzyme catalysisProtein structuresAmino acid synthesisPolypeptide chainsBiomolecule properties

Biomolecules and Enzymes Questions

Multiple choice bio-chemistry proteins denaturation of protein proteins and amino acids proteins and enzymes

 Peptide linkages ($\displaystyle CONH$) are present in the primary structures of proteins while the secondary structures of proteins involve ______. 

  1. Coordinate bonding

  2. Ionic bonding

  3. hydrogen bonding

  4. none
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

While primary structure is held together by covalent peptide bonds, secondary structures (like alpha-helices and beta-pleated sheets) are formed and stabilized by hydrogen bonding between the backbone atoms.

Multiple choice bio-chemistry proteins denaturation of protein proteins and amino acids proteins and enzymes

The building block of proteins are:

  1. $\alpha$-hydroxy acid
  2. $\alpha$-amino acid
  3. $\beta$- hydroxy acid
  4. $\beta$- amino acid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The building block of proteins are $ \displaystyle \alpha-$amino acids.
On hydrolysis, proteins gives  $ \displaystyle \alpha-$amino acids.
 $ \displaystyle \alpha-$amino acids have structure  $ \displaystyle H _2N- \underset {  \displaystyle   { \underset {  \displaystyle  \text { R } }{ | } } }{CH }-COOH$
Proteins $ \displaystyle \xrightarrow {H _2O}n H _2N- \underset {  \displaystyle   { \underset {  \displaystyle  \text { R } }{ | } } }{CH }-COOH$
Proteins are polypeptides and contain peptide linkage ($ \displaystyle - \underset {  \displaystyle   { \underset {  \displaystyle  \text { O } }{ || } } }{C }-NH-$ linkage)

Multiple choice

Which of the following is NOT a type of protein found in the human body?

  1. Enzymes

  2. Antibodies

  3. Hormones

  4. Carbohydrates
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Carbohydrates are not a type of protein. Proteins are made up of amino acids, while carbohydrates are made up of sugars.

Multiple choice

Which of the following techniques is used to determine the three-dimensional structure of a protein?

  1. X-ray crystallography

  2. Nuclear magnetic resonance (NMR) spectroscopy

  3. Electron microscopy

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

X-ray crystallography, NMR spectroscopy, and electron microscopy are all techniques that can be used to determine the three-dimensional structure of a protein.

Multiple choice

What is the primary structure of a protein?

  1. The sequence of amino acids in the protein

  2. The three-dimensional structure of the protein

  3. The number of amino acids in the protein

  4. The molecular weight of the protein
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The primary structure of a protein is the sequence of amino acids in the protein.

Multiple choice

What is the secondary structure of a protein?

  1. The arrangement of amino acids into alpha helices and beta sheets

  2. The three-dimensional structure of the protein

  3. The number of amino acids in the protein

  4. The molecular weight of the protein
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The secondary structure of a protein is the arrangement of amino acids into alpha helices and beta sheets.

Multiple choice

What is the tertiary structure of a protein?

  1. The three-dimensional structure of the protein

  2. The arrangement of amino acids into alpha helices and beta sheets

  3. The number of amino acids in the protein

  4. The molecular weight of the protein
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The tertiary structure of a protein is the three-dimensional structure of the protein.

Multiple choice

What is the quaternary structure of a protein?

  1. The arrangement of multiple protein subunits into a single complex

  2. The three-dimensional structure of the protein

  3. The number of amino acids in the protein

  4. The molecular weight of the protein
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The quaternary structure of a protein is the arrangement of multiple protein subunits into a single complex.

Multiple choice

Which of the following is an example of a protein with a quaternary structure?

  1. Hemoglobin

  2. Myoglobin

  3. Insulin

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

Hemoglobin is an example of a protein with a quaternary structure. It is composed of four subunits, each of which contains a heme group.

Multiple choice

Which of the following is an example of a protein that catalyzes a chemical reaction?

  1. Enzymes

  2. Antibodies

  3. Hormones

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

Enzymes are proteins that catalyze chemical reactions.

Multiple choice

Which of the following is an example of a protein that transports molecules?

  1. Hemoglobin

  2. Myoglobin

  3. Insulin

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

Hemoglobin is a protein that transports oxygen.

Multiple choice

Which of the following is an example of a protein that provides structural support?

  1. Collagen

  2. Elastin

  3. Keratin

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

Collagen is a protein that provides structural support.

Multiple choice

What is the difference between a protein and a polypeptide?

  1. A protein is a single polypeptide chain, while a polypeptide is a chain of amino acids that has not yet been folded into a functional protein.

  2. A protein is a chain of amino acids that has been folded into a functional protein, while a polypeptide is a single polypeptide chain.

  3. There is no difference between a protein and a polypeptide.

  4. Proteins and polypeptides are both chains of amino acids.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A protein is a chain of amino acids that has been folded into a functional protein, while a polypeptide is a single polypeptide chain.

Multiple choice

What is the difference between a protein and an enzyme?

  1. A protein is a single polypeptide chain, while an enzyme is a protein that catalyzes a chemical reaction.

  2. A protein is a chain of amino acids that has been folded into a functional protein, while an enzyme is a single polypeptide chain.

  3. There is no difference between a protein and an enzyme.

  4. Proteins and enzymes are both chains of amino acids.
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

A protein is a chain of amino acids that has been folded into a functional protein, while an enzyme is a protein that catalyzes a chemical reaction.

Multiple choice

What is the difference between a protein and a nucleic acid?

  1. A protein is a chain of amino acids, while a nucleic acid is a chain of nucleotides.

  2. A protein is a chain of amino acids that has been folded into a functional protein, while a nucleic acid is a single polypeptide chain.

  3. There is no difference between a protein and a nucleic acid.

  4. Proteins and nucleic acids are both chains of amino acids.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A protein is a chain of amino acids, while a nucleic acid is a chain of nucleotides.