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 enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

One of the following enzyme is used to cut genes at specific sites, therefore, useful in recombinant technology

  1. Ligase

  2. Topoisomerase

  3. Pepsin

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

Restriction endonuclease are a part of cellular defense system in bacteria. These enzymes cleave or restrict external or exogenous DNA. A type of these enzymes act on specific palindromic sequences which they recognize.

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

An organic substance bound to an enzyme and essential for its activity is called as

  1. Apoenzyme

  2. lsoenzyme

  3. Coenzyme

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

Enzymes are simple if they are made up of only proteins, e.g., pepsin, amylase, etc., while conjugate enzymes have an additional non-protein cofactor, e.g., dehydrogenase enzymes. The cofactor can be organic or inorganic. Loosely attached organic cofactor are called coenzymes, e.g., NAD, FAD etc., while firmly attached one is prosthetic group, e.g., haeme, biotin etc.

Multiple choice biology biotechnology and genetic engineering stds and infertility gm crops biotechnology

Enzymes can be immobilized by

  1. Cross-linking enzyme molecules

  2. Covalently attaching to a solid support

  3. Entrapping them in gel

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

There are four principal methods available for immobilizing enzymes as follows:

(a) Enzyme non-covalently adsorbed to an insoluble particle; 
(b) Enzyme covalently attached to an insoluble particle; 
(c) Enzyme entrapped within an insoluble particle by a cross-linked polymer; 
(d) Enzyme confined within a semi-permeable membrane.

Multiple choice biology biotechnology and genetic engineering stds and infertility gm crops biotechnology

Rennin used in cheese industry is an

  1. Anitibiotic

  2. Alkaloid

  3. Enzyme

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

Rennin, also called as chymosin, protein-digesting enzyme that curdles milk by transforming caseinogen into insoluble casein; it is found only in the fourth stomach of cud-chewing animals, such as cows. Its action extends the period in which milk is retained in the stomach of the young animal. In animals that lack rennin, milk is coagulated by the action of pepsin, as is the case in humans. A commercial form of rennin, rennet, is used in manufacturing cheese and preparing junket.

Multiple choice biology biotechnology and genetic engineering stds and infertility gm crops biotechnology

Single cell protein refers to

  1. Specific protein extracted from pure culture of single type of cells.

  2. Sources of mixed proteins extracted from pure or mixed culture of organisms or cells.

  3. Proteins extracted from a single cell.

  4. A specific protein extracted from a single cell.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Single-cell protein refers to sources of mixed protein extracted from pure or mixed cultures of algae, yeasts, fungi or bacteria (grown on agricultural wastes) used as a substitute for protein-rich foods, in human and animal feeds.

Multiple choice biology biotechnology and genetic engineering stds and infertility gm crops biotechnology

Rennin used in cheese industry is a/an

  1. Antibiotic

  2. Enzyme

  3. Alkaloid

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

Chymosin, known also as rennin, is a proteolytic enzyme synthesized by chief cells in the stomach in young ruminants. Its role in digestion is to curdle or coagulate milk in the stomach, in the very young animal. Chymosin efficiently converts liquid milk to a semisolid like cottage cheese, allowing it to be retained for longer periods in the stomach. It is widely used in the production of cheese. 

Multiple choice biology biotechnology and genetic engineering stds and infertility gm crops biotechnology

Which of the following is used to promote the growth of new blood vessels, thus help in wound healing?

  1. Humulin

  2. TPA
  3. TGF-$\beta$
  4. $\alpha$-1 antitrypsin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Transforming Growth Factor beta (TGF-beta) is a protein that plays a critical role in tissue repair, cell growth, and the formation of new blood vessels (angiogenesis) during wound healing.

Multiple choice biology digestion and absorption liver functions of the liver secretory organs

Which of the following blood proteins (clotting factors) are produced by liver?

  1. Thrombin and prothrombin

  2. Anti hemophilic and fibrinogen

  3. Prothrombin and Fibrinogen

  4. Thromboplastin and thrombin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The liver synthesizes most of the major plasma proteins involved in blood coagulation, notably prothrombin and fibrinogen. Other factors like thrombin are active enzymes converted in the blood rather than directly synthesized as active factors by the liver.

Multiple choice

Lack of essential amino acids affects:

  1. Production of glycogen

  2. Breakdown of glycogen

  3. Production of proteins

  4. Breakdown of proteins
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Proteins are composed of amino acids. If essential amino acids are missing from the diet, the body cannot synthesize the specific proteins required for growth and repair.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

Detailed structure of biological molecules can be known with the help of _____________.

  1. Atomic force microscope.

  2. Scanning probe microscope.

  3. Scanning tunneling microscope.

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

Atomic force microscopy (AFM) is a type of scanning probe microscopy capable of imaging surfaces at the atomic level, providing detailed topographical information about biological molecules.

Multiple choice

What happens when a signal molecule binds to a receptor protein?

  1. a second messenger is activated inside the receiving cell

  2. the permeability of the cell changes

  3. enzyme activity is triggered in the cell

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

Binding of a signal molecule to a receptor can trigger various cellular responses, including activation of second messengers, changes in membrane permeability, and alteration of enzyme activity.

Multiple choice

Study of protein structure are

  1. Genomics

  2. Proteomics

  3. Both a ,b

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

Proteomics is the large-scale study of proteomes, which are the entire sets of proteins produced or modified by an organism. This field includes the study of protein structures, functions, and interactions.