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 evs transportation in living organisms blood in humans circulatory system - blood basics of blood and heart

Statements:
A. Plasma constitutes 45% of the human blood
B. Albumin is a plasma protein which helps in osmotic balance
C. Factors responsible for the blood clotting process are
present in the blood
D. Plasma without clotting factors is called serum
E. Minerals are not generally found in blood Of the above statements.

  1. Only E is wrong and all other A to D are correct

  2. A and B are correct and C, D and E are wrong

  3. B and D are correct and A, C and E are wrong

  4. A and E are correct and B, C and D are wrong

  5. B,C and D are correct and A and E are wrong
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Statement A is incorrect because plasma is about 55% of blood. Statement E is incorrect because minerals (electrolytes) are essential components of blood plasma. Statements B, C, and D are standard physiological facts.

Multiple choice evs transportation in living organisms blood in humans circulatory system - blood basics of blood and heart

What is correct about haemoglobin?
1. Oligomeric protein 2. Chromoprotein 3. Monomeric protein 4. Keratin.

  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
B Correct answer
Explanation

Haemoglobin is an oligomeric protein (composed of four subunits) and a chromoprotein (due to the iron-containing haem group). It is not monomeric, nor is it keratin.

Multiple choice zoology locomotion and reproduction flagella other cell components single membrane bound organelles

The principal protein of cilia and flagella is

  1. Tubulin

  2. Albumin

  3. Globulin

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

The cytoskeletal structures are of three types : microtubules (made of tubulin protein), microfilaments (made of actin protein) and intermediate fibres (made of keratin protein). 

Microtubules are basic structures of spindle apparatus, centrioles, basal bodies, cilia and flagella.

Multiple choice zoology locomotion and reproduction flagella other cell components single membrane bound organelles

Tubulin binds colchicine and which of the following, at different binding sites?

  1. Vincristin

  2. Vinblastin

  3. Actin

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

Vincristin and Vinblastin are important anti cancer drugs, isolated from Althea rosea. These drugs inhibit spindle formation and thus arrest uncontrolled division of cancer cells. Tubulin are important cytoskeletal elements. Actin, Myosin are important for cellular movements. Motor proteins utilizing the cytoskeleton for movement fall into two categories based on their substrates: Actin motors such as myosin move along microfilaments through interaction with actin. 

Multiple choice evs nutrition and its deficiency general functions of food nutrition and its need in plants nutrition and its need

Read the statements given below.
(1) The element which is very important for the production of thyroxine is iodine.
(2) Vitamin ${B _6}$ is otherwise known as niacin or nicotinic acid.
(3) Fructose is a monosaccharide and is a hexose sugar.
(4) Globulin is an example for a conjugated protein.
Of the above statements

  1. 1, 2 and 3 are correct but 4 is wrong.

  2. 1 and 3 are correct but 2 and 4 are wrong.

  3. 1 and 2 are correct but 3 and 4 are wrong.

  4. 1 is correct while 2, 3 and 4 are wrong.

  5. 1, 3 and 4 are correct but 2 is wrong.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Iodine is an essential mineral element. It is required for production of hormones thyroxine by thyroid glands. Deficiency of thyroxine causes swelling of thyroid or goitre. It's deficiency also leads to mental retardation, increased abortions, still births and infant deaths. Vitamin B$ _{6}$ is otherwise known as pyridoxine. It is a component of coenzyme pyridoxal phosphate. Fructose is a hexose monosaccharide ketose sugar abundant in fruits. Globulins are a family of globular proteins. Mostly they are simple storage proteins which are soluble in dilute salt solution and coagulated by heat example arachin of groundnut, legumin of pulses, vitellin of egg yolk etc.

Multiple choice evs nutrition and its deficiency general functions of food nutrition and its need in plants nutrition and its need

Proteins are mainly required in the body for

  1. Growth

  2. Repair

  3. Both A and B

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Proteins are the major body building biomolecules. Proteins serve a variety of structural and functional roles. They are required to produce new tissues and repair old worn out parts. They play an important role in cellular defense mechanism as immunoglobulins. Most enzymes are proteins.  Meat, milk and eggs are an important source of proteins. Soybean and other pulses are an important source of plant proteins.

Multiple choice bio-chemistry immunity and blood groups active and passive immunity acquired immunity innate and acquired immunity

Antigenic determinants bind to which of the following portions of an antibody?

  1. Variable regions

  2. Constant region

  3. Only light chains

  4. Only heavy chains
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The specific region on an antigen that an antibody recognizes and binds to is called the epitope, or antigenic determinant. An epitope is usually 5-8 amino acids long on the surface of the protein. Proteins are three dimensionally folded structures, and an epitope may only be recognized in its form as it exists in solution, or its native form. The antigen binding portion of an antibody varies extensively among secreted antibodies, and this length of sequence is known as the variable region. The variable region construction during antibody production in the B cell is what enables antibodies to be generated against an infinite variety of antigens. The other biological properties of the antibody and its role in signaling to other immune cells are determined by the constant regions of the heavy chains.


So, the correct option is 'Variable regions'.

Multiple choice zoology endocrine system and chemical co-ordination pineal gland pituitary gland and pineal gland pineal gland and thymus

Melatonin is modified

  1. Amino acid

  2. Peptide

  3. Steroid

  4. Protein
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Melatonin is a hormone that regulates sleep-wake cycles. It is primarily released by the pineal gland. 
  • As a supplement, it is often used for the short-term treatment of trouble sleeping such as from jet lag or shift work. 
  • Melatonin is a hormone which is a protein made up of amino acids. 
  • Hence, Melatonin is a modified Amino acid. 
  • So, the correct answer is 'amino acid'.
Multiple choice bio-chemistry diseases and immunity antibodies antibodies and antitoxin antigen and antibody

Chemically, an antibody is a

  1. Protein

  2. Lipoprotein

  3. Lipid

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

An antibody, also known as an immunoglobulin is a large, Y-shaped protein which is produced mainly by plasma cells and it is used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses. Antibodies are secreted by B lymphocytes of the adaptive immune system, mostly by differentiated B cells called plasma cells. Hence, chemically, an antibody is a protein.

So, the correct answer is 'Protein'.

Multiple choice bio-chemistry diseases and immunity antibodies antibodies and antitoxin antigen and antibody
Antibodies belong to which class of proteins?

  1. Structural

  2. Transport

  3. Immunoglobulin

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

An antibody which belongs to the class of immunoglobulin is a large, Y-shaped protein which is produced mainly by plasma cells and it is used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses. Antibodies are secreted by B lymphocytes of the adaptive immune system, mostly by differentiated B cells called plasma cells. 

So, the correct answer is 'Immunoglobulin'.

Multiple choice bio-chemistry diseases and immunity antibodies antibodies and antitoxin antigen and antibody

Binding of antigen to antibody is through

  1. Electrostatic intereactions

  2. Covalent bonds

  3. Disulphide bridges

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

Antibodies bind antigens through weak chemical interactions, and bonding is essentially non-covalent. Electrostatic interactions, hydrogen bonds, van der Waals forces, and hydrophobic interactions are all known to be involved depending on the interaction sites.

So, the correct answer is 'Electrostatic intereactions'.

Multiple choice zoology locomotion and movement contractile protein structure of muscle muscles and their structure

State whether the following statements are true or false.
Actin is actually a globular protein that assembles as a long beady structure consisting of two helical chains.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Skeletal muscle is composed of muscle fibres which have smaller units called myofibrils. There are three types of proteins make up each myofibril; they are contractile, regulatory and structural proteins. By contractile proteins, we mean actin (thin filament), a globular protein assembling with a long beady structure consisting chains and myosin (thick filament).

So, the correct option is 'True'.