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 botany cell cycle difference between meiosis and mitosis division for growth and reproduction meiosis

If the activity of an enzyme is constant over a broad range of pH values,it is likely that

  1. only ionizing groups on the enzyme participate in the reaction

  2. only ionizing groups on the substrate participate in the reaction

  3. ionizing groups on the enzyme and substrate participate in the reaction

  4. the temperature should be changed in order to observe a pH effect
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Changes in pH may influence the state of a catalyst as well as change the shape or charge properties of the substrate so that either the substrate can not tie to the dynamic site or it can't experience catalysis. In general, protein has a pH ideal. Anyway, the ideal isn't the equivalent for every chemical. 
So, the correct option is 'only ionizing groups on the enzyme participate in the reaction'
Multiple choice biology biotechnology and genetic engineering making use of enzymes genetic technology genetic engineering

Nitrocellulose and nylon are used in which of the following technique of immobilisation?

  1. Entrapment

  2. Encapsulation

  3. Adsorption

  4. Cross-linking
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Encapsulation involves enclosing enzymes within a semi-permeable membrane, such as nitrocellulose or nylon, to immobilize them while allowing substrate and product diffusion.

Multiple choice biology classification and variation dna - history and structure biotechnology commercial applications of biotechnology

Which of the following staement is related to interferon?

  1. It is a protein released by animal cells

  2. It is released in response to the entry of a virus

  3. It has the property of inhibiting virus replication

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

Interferons are a group of proteins called cytokines, produced by animal white blood cells, fibroblasts or T-cells as part of the immune response to a viral infection or other immune trigger. The name of proteins comes from their ability to interfere with the replication of new virus particles.
Interferons do not directly kill viral or cancerous cells. They boost the immune system response and reduce the growth of cancer cells by regulating the action of several genes that control the secretion of numerous cellular proteins that affect the growth.
The virus infected cells secrete a special protein that causes both infected and non infected cells, to produce other proteins that prevent viruses from replicating and protecting the non infected cells.
So the correct option is 'All of the above'.

Multiple choice zoology applications of biotechnology cloning process of cloning gene cloning

Technique used to detect the DNA in a clone is?

  1. Polymerase chain reaction

  2. Gel electrophoresis

  3. Chromatography

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

PCR (Polymerase Chain Reaction) is a technique used to amplify specific DNA sequences, making it possible to detect and analyze DNA in a clone or sample.

Multiple choice biology animals in daily life earthworm - reproductive system reproduction in earthworm introduction to reproduction poultry farming food from animals

Protein of yolk is

  1. Casein and phosphovitin

  2. Lecithin and lipovitellin

  3. Phosphovitin and lipovitellin

  4. Casein and lecithin
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The different yolk's protein has distinct roles. Phosvitins are important in sequestering calcium, iron and other cations for the developing embryo. Phosvitins are one of the most phosphorylated (10%) proteins in nature, the high concentration of phosphate groups providing efficient metal-binding sites in clusters. Lipovitellins are involved in lipid and metal storage, and contain a heterogeneous mixture of about 16%  noncovalently bound lipid, most being phospholipid. Lipovitellin-1 contains two chains, LV1N and LV1C. Hence, option C is correct.

Multiple choice bio-chemistry digestive system of human digestive system- glands mouth and buccal cavity digestive glands

A lubricant mucin, in saliva, is made up of

  1. Polyunsaturated fats

  2. Actin and myosin

  3. Glycoproteins

  4. Phospholipids
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
A. Polyunsaturated fats are the fats in which hydrocarbon chain has two or more double bonds.
B. Actin and myosin are the protein filaments which help in muscle contraction.
C. Proteins associated with carbohydrates i.e. sugars attached to them, are called glycoproteins.
D. Lipids that contain a phosphate group, are called phospholipids.
The lubricant mucin in saliva is a glycoprotein. 
So, the correct answer is 'Glycoproteins'.
Multiple choice zoology molecular basis of inheritance the search for genetic material dna structure and replication molecular genetics

Genetic code determines

  1. Sequence of amino acids in protein chain

  2. Variations

  3. Constancy of morphological traits

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

The genetic code is a set of rules by which information encoded in genetic material is translated into proteins by living cells, specifically determining the sequence of amino acids.

Multiple choice zoology molecular basis of inheritance the search for genetic material dna structure and replication molecular genetics

Find out the correct options
1. Amino acids may have more than one codon
2. All amino acids have more than one codon
3. Codons are common for higher and lower organisms
4. Codons are not found in bacteria

  1. 1, 2, 3 correct

  2. 1, 2 correct

  3. 2, 4 correct

  4. 1, 3 correct
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Statement 1 is correct because the genetic code is degenerate (multiple codons for one amino acid). Statement 3 is correct because the genetic code is nearly universal. Statement 2 is false because some amino acids like methionine have only one codon. Statement 4 is false because bacteria use the same codon system.

Multiple choice zoology molecular basis of inheritance the search for genetic material dna structure and replication molecular genetics

Beside direct chemical analysis DNA and RNA can be detected by which of the following method?
a. Photometric procedures
b. Staining reactions
c. Enzyme digestion
Select the correct answer using the codes given.

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

DNA and RNA can be detected using photometric procedures (like UV absorbance), staining reactions (like Feulgen stain for DNA), and enzyme digestion (using DNase or RNase to confirm identity).

Multiple choice biology the life cycle of animals how do animals reproduce? excretory, nervous and reproductive system structure and functions of living organisms -ii

Cry gene which synthesize crystal protein is isolated from

  1. Bacillus thuringiensis

  2. Rhizobium

  3. Bacillus polymyxa

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

Bacillus thuringiensis (Bt) is a Gram-positive bacterium that produces crystals during sporulation. These crystals comprise ~130 kDa protoxins called crystal proteins which are potent and highly specific insecticides. Once ingested by specific host, these crystals dissolve in the alkaline conditions of the gut thereby activating the protoxins. The active toxins then bind to receptors on midgut epithelial cells, become inserted into the plasma membrane where they form pores leading to cell death through osmotic lysis. Option A is the correct answer.