Biology · Chemistry

Biomolecules and Enzymes

1,501 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 carbohydrate metabolism energy output living organisms and energy production respiration in cell
Amount of energy released during hydrolysis of a high energy bond of ATP is
  1. $73 Kcal \,{mol}^{-1}$
  2. $0.73 Kcal \,{mol}^{-1}$
  3. $3.4 Kcal\, {mol}^{-1}$
  4. $7.3 Kcal \,{mol}^{-1}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Adenosine triphosphate(ATP) is the energy currency of the cell. It is the most important energy carrier which carries energy in the two terminal phosphate bonds(called as high energy bonds or energy-rich bonds). Equal amounts of usable energy are released per mole of ATP or ADP hydrolysis:
$ATP+{H} _{2}O\rightleftharpoons ADP+Pi+7.3Kcal{\,\,mol}^{-1}$
$ADP+{H} _{2}O\rightleftharpoons AMP+Pi+7.3Kcal{\,\,mol}^{-1}$
So the correct answer is '$7.3 Kcal \,{mol}^{-1}$'.
Multiple choice bio-chemistry minerals minerals and vitamins nutrition and diet role of various nutrients

Which one is wrong combination?

  1. $N _2$-Amino acid

  2. Fe-cytochrome

  3. Na-Protein

  4. Mg-Chlorophyll

  5. P-DNA
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Na- Protein is wrong combination as Nitrogen (N) is needed for the protein formation. Nitrogen is the main constituent of the amino acid that helps in the formation of protein

Thus, the correct answer is option C.

Multiple choice biology respiration in plants fermentation cell respiration living organisms and energy production

Enzyme that changes glucose to ethyl alcohol is

  1. Zymase

  2. Diastase

  3. Invertase

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

A) Zymase causes the breakdown of sugars into alcohols.

B) Diastase catalyses the breakdown of starch into maltose.
C) Invertase is an enzyme that catalyses the breakdown of sucrose into fructose and glucose.
D) Maltase breaks down maltose to glucose.
So the correct answer is 'Zymase'

Multiple choice biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Consider the following statements.
a. Copper is present in Cytochrome oxidase
b. Pantothenic acid is the precursor of Coenzyme A
c. Thiamine pyrophosphate is the prosthetic group in decarboxylases
d. Zinc is present in RNA and DNA polymerases
Which of these statements are correct?

  1. $1$ and $2$
  2. $2, 3$ and $4$
  3. $1, 2, 3$ and $4$
  4. $1, 3$ and $4$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

All four statements are accurate: copper is a cofactor in cytochrome oxidase, pantothenic acid is a precursor for Coenzyme A, thiamine pyrophosphate serves as a prosthetic group for decarboxylases, and zinc is an essential structural or catalytic ion in DNA and RNA polymerases.

Multiple choice biology plant growth and development other plant hormones cytokinins, ethylene and abscisic acid plant hormones

How many high-energy phosphate bond equivalents are utilized in the process of activation of amino acids for protein synthesis?

  1. Four

  2. Two

  3. One

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

During the activation of an amino acid prior to protein synthesis, the amino acid reacts with ATP to form aminoacyl-AMP and pyrophosphate (PPi). The hydrolysis of PPi subsequently releases energy equivalent to another high-energy bond, consuming a total of two high-energy phosphate equivalents per activated amino acid.

Multiple choice biology control and coordination in living organisms control of blood glucose endocrine system and hormone hormones in human reproduction testes and ovary parts of the brain kidney

Which of the following is not a example of sex pheromone? 

  1. Bombykol

  2. Muskone

  3. Formic acid

  4. Civetone
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Formic acid is the simplest carboxylic acid and occurs naturally, mostly in ant venom. 

Sex pheromones are pheromones released by an organism to attract an individual of the opposite sex, encourage them to mate with them, or perform some other function closely related with sexual reproduction. Volatile pheromones are characterized as sex pheromones and usually form a specific odour and are focused on alarm sensitivity. 
Bombykol, the sex pheromones of silkworm moths, civetone from the civet cat and muskone from the musk deer are examples of sex pheromones.

Multiple choice zoology endocrine system and adolescence control of blood glucose endocrine system and hormone hormones in human reproduction

Which of the following are incorrectly matched

  1. Synthesis reaction-anabolism

  2. Decomposition reaction-catabolism

  3. Hydrolysis-anabolism

  4. Dehydration reaction-synthesis reaction
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Hydrolysis is the cleavage of biomolecules where a water molecule is consumed to affect the separation of a larger molecule into component parts. So, hydrolysis is a type of decomposition and that's why it is regarded as catabolism.
Hence, the correct answer is 'Hydrolysis-anabolism'
Multiple choice biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

Select the type of enzyme involved in the above reaction.

$\boxed{S - G + S' \rightarrow S + S' - G}$

  1. Dehydrogenase

  2. Transferase

  3. Hydrolase

  4. Lyase

  5. Isomerase
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Transferases are the enzymes that catalyze group transfer reactions. In the figure, one group G has been transferred to another group S'. It is a classical example of a group transfer reaction.

Multiple choice biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

Basically how many types of enzymes have been recognised by International Union of Biochemistry?

  1. 4

  2. 5

  3. 6

  4. 8
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

According to the modern classification system given by International Union of Biochemistry, enzymes have been classified into six classes as follows :
Class First is Oxidoreductase.
Class Second is Transferase.
Class Third is Hydrolase.
Class Fourth is Lyase.
Class Fifth is Isomerase.
Class Sixth is Ligase.

Multiple choice biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

Enzymes concerned with transfer of electrons are

  1. Hydrolase

  2. Dehydrogenase

  3. Transaminase

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

Dehydrogenases catalyze dehydrogenation reactions, which involve addition or removal of electrons. Addition or removal of electrons will lead to reduction or oxidation of substrates. Dehydrogenases are a type of oxidoreductases.