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

Which of the following statements about enzyme DD-transpeptidase is true?

  1. It provides antigenicity to the cell wall.

  2. It makes the cell wall semi-permeable.

  3. It makes the cell wall strong and rigid.

  4. It breaks the amino acid linkages in the cell wall.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

DD-transpeptidase helps in cross linking between amino acids in different linear sugar amino chains. It results in a 3-dimensional structure that is strong and rigid.

Multiple choice

Abnormally folded prion proteins are generally

  1. relatively sensitive to protease digestion

  2. associated with CGD

  3. present in follicular dendritic cells in individuals with transmissible spongiform encephalopathies

  4. normally eliminated by B-cells

  5. destroyed by macrophages
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

FDCs naturally express high levels of the normal prion protein which then becomes abnormal following exposure to the transmissible spongiform encephalopathy (TSE) agent.

Multiple choice

The most abundant protein found on Earth is

  1. PEP caroxylase

  2. RUBISCO

  3. Aldolase

  4. Transketolase
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

RUBISCO (Ribulose-1,5-bisphosphate carboxylase/oxygenase) is Earths most abundant protein. It catalyzes carbon fixation in photosynthetic organisms plants, algae, cyanobacteria comprising up to 50% of leaf soluble protein.

Multiple choice

The three-dimensional shape of protein is maintained by

  1. hydrogen bonds

  2. peptide bonds

  3. ionic bonds

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Each protein has a specific three-dimensional structure that is maintained by hydrogen bonds. Normal protein functions require the maintenance of this structure.

Multiple choice

Dietary proteins that contain all 10 essential amino acids are called

  1. complete proteins

  2. supplementary proteins

  3. complementary proteins

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

Dietary proteins that contain all 10 essential amino acids are called complete proteins, while that dietary proteins which contain some, but not all, of the essential amino acids are called incomplete proteins. Plant proteins are considered incomplete proteins.