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 - i community health and hygiene drug, tobacco and alcohol consumption addiction and dependence important stages in agricultural development disorders of nervous system

The tobacco protein induced arteriosclerotic disease is

  1. Aneurysm

  2. Polyarteritis nodosa

  3. Thromboangiitis obliterans

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

Thromboangiitis obliterans, also called Buerger disease is a rare disease caused by small blood vessels that become inflamed and swollen. The blood vessels, then narrow or become completely blocked by the blood clots (Thrombosis). Blood vessels of the hand and feet are especially affected. This condition mostly affects young men, ages, 20-40, who are heavy smokers or chew tobacco.
Thus, the correct answer is option (A), 'Thromboangiitis obliterans'

Multiple choice botany living world and classification of microbes gram staining microbiology: organisms in industry cell wall and cell membrane

All the following statements are true about exotoxins except 

  1. They are protein in nature.

  2. Are heat labile.

  3. Produced by Gram + positive bacteria.

  4. Are highly antigenic.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

An exotoxin is a toxin secreted by bacteria. An exotoxin can cause damage to the host by destroying cells or disrupting normal cellular metabolism. Exotoxin is secreted during lysis of the cell. 

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

The murein found in bacterial cell is

  1. Derivative of protein

  2. Derivative of fat

  3. Derivative of organic acids

  4. Derivative of sugars
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The mucopeptide or murein is a polymer of two amino sugars namely N-acetylglucosamine (NAG) and N-acetyl muramic acid (NAM). These NAG and NAM are derivatives of Glucose molecules.

Thus, the correct answer is 'D'.

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane
What is the percentage of mucopolypeptide in the cell wall of Gram (+) bacterium?
  1. $60-70\%$
  2. $70-80\%$
  3. $80-90\%$
  4. $90-100\%$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The mucopeptide is a peptidoglycan that is insoluble in nature. It is also called as murein. It is present in almost all bacterial cell walls. However, its percentage is higher in cell wall of gram positive bacteria than in cell wall of gram negative bacteria. 

So, B is the correct answer. 

Multiple choice evs production of food from animals dairy farm management cattle farming uses of animals contribution of louis pasteur discoveries by louis pasteur discovery of microorganisms

Casein is a protein present in milk. Which group of protein is associated with casein?

  1. Nucleoprotein

  2. Chromoprotein

  3. Phosphoprotein

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

  • A phosphoprotein are a group of conjugated proteins, like casein, in which the protein molecule is bound to phosphoric acid. 
  • Casein is a phosphoprotein. These proteins are commonly found in mammalian milk, making up 80% of the proteins in cow milk and between 20% and 45% of the proteins in human milk.

Therefore, the correct answer is option C.

Multiple choice biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

Enzymes, vitamins and hormones are common in

  1. Being proteinaceous

  2. Being synthesised in the body organisms

  3. Enhancing oxidative metabolism

  4. Regulating metabolism
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Feedback inhibition is the process by where the end product terminates the reaction. The accumulation of the end product interferes with the enzymatic activity by changing the shape of its active site. Enzymes and hormones regulate the metabolism by feedback inhibition.
Enzymes are protein in nature and catalyzes the biological reaction without being used up in the chemical reaction. They regulate the chemical reaction by feedback inhibition. 
Hormones are the chemical messenger which activates the effector gland and regulate the metabolism by feedback inhibition.
Vitamins acts as a coenzymes which regulates the enzymatic activity and further regulate the metabolism.
So, the correct answer is option D.

Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Signalling between cells usually results in activation of protein by

  1. Kinases

  2. Proteases

  3. Lipases

  4. Nucleases
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Signalling is the communication between cells by means of signalling molecules. When a ligand binds to its receptor, ligand-receptor complex is formed which activate protein kinases. Kinases are the enzymes that transfer phosphate group to the target cells. Phosphorylation of target cells cause different changes in the cell.
So, the correct answer is 'Kinases'.
Multiple choice zoology endocrine system and chemical co-ordination mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Insulin receptors are.

  1. Extrinsic proteins

  2. Intrinsic proteins

  3. G-proteins

  4. Trimeric proteins
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Insulin receptors are extrinsic proteins. They are made up of an alpha and a beta subunit that are held together by disulphide bonds. Insulin, which is a polypeptide hormone, binds to the extracellular face of the α-subunits.
Thus, the correct answer is 'Extrinsic proteins.'
Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans
Feed back inhibition of an enzyme is influenced by

  1. Enzyme itself

  2. External factors

  3. End product

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

In feed back inhibition product of a reaction inhibits the enzyme catalysing that reaction. It is a type of control mechanism at the enzyme level. If the product is produced in sufficient amount, it inhibits the enzyme to stop the further production. So, the correct answer is 'End product'.

Multiple choice biology soldiers of defense blood clotting and healing of wounds coagulation of blood blood clotting

Identify $A,B$ and $C$ in the given blood clotting process.
Damage platelets release $A$;$A$ converts $D$ into $B$ in presence of Calcium ions. $B$ converts $C$ into Fibrin thread.

  1. A-Thromboplastin,B-Prothrombin,C-Fibrinogen

  2. A-Thrombin,B-Fibrinogen,C-Thrombo-kinase

  3. A-Thromboplastin,B-Thrombin,C-Fibrinogen

  4. A-Prothrombin,B-Thrombin,C-Fibrinogen
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In the clotting cascade, damaged platelets release thromboplastin (A), which converts prothrombin (D) into thrombin (B) in the presence of calcium. Thrombin then converts fibrinogen (C) into fibrin threads.