Question Bank | Bio-11, Ch-03

Here is a vast collection of objective and subjective questions in this question bank of biology 11, chapter 03. Following types of questions have been included here.

  • MCQs (Textbook Exercise)
  • MCQs (Previous Boards Essentials)
  • SQs Topic-wise (Previous Boards Essentials + Textbook Conceptuals)
  • LQs (Previous Boards Essentials)

You can find solutions to these questions from our publication, “An Insight Into Objective Biology-11”.

MCQs (Textbook Exercise)

Q. Each question has four possible answers. Tick the correct one.

01: If more substrate to an already occurring enzymatic reaction is added, more enzyme activity is seen because: (BWP-14)

(a)    There is probably more substrate present than there is enzyme.

(b)   There is probably more enzyme available than there is substrate.

(c)    There is probably more product present than there is either substrate or enzyme.

(d)   The enzyme substrate complex is probably failing to form during the reaction.

02: If you add more substrate to already occurring enzymatic reaction and it has no effect on the rate of reaction. What is the form given for this situation? (LHR-14)          

(a)    Saturation                        

(b)   Denaturation

(c)    Composition                    

(d)   Inhibition

03: The rate of an enzyme catalyzed reaction: (MLT-15)

(a)    Is constant under all conditions.

(b)   Decreases as substrate concentration increases.

(c)    Can not be measured.

(d)   Can be reduced by inhibitors.

04: The active site of an enzyme: (MLT-14)

(a)    Never changes

(b)   Forms no chemical bond with substrate

(c)    Determines, by its structure, the specificity of the enzyme

(d)   Looks like a lump projecting from the surface of the enzyme

05:   Which statement about enzyme is not true? (MLT-16)

(a)    They consist of proteins, with or without a non-protein part.

(b)   They change the rate of catalyzed reaction.

(c)    They are sensitive to heat.

(d)   They are non-specific in their action.

MCQs (Previous Boards Essentials)

Q. Each question has four possible answers. Tick the correct one.

01: Biologically active proteins: (SWL-17)

(a) Glycoproteins                  

(b) Enzymes

(c) Activators                        

(d) Inhibitors

02: All enzymes are globular: (SRG-14)

(a) Carbohydrates                  

(b) Lipids

(c) Nucleic acids                   

(d) Proteins

03: The non-protein part of the enzyme is known as: (GJR-17)

(a) Activator                         

(b) Co-enzyme

(c)  Co-factor                         

(d) Polypeptides

04: The detachable (inorganic) co-factor of an enzyme is known as: (GJR-14,22)(AJK-16)(RWP-18)

(a) Activator                         

(b) Prosthetic group

(c) Coenzyme                      

(d) Apoenzyme

05: Metal ions are related to: (GJR-15)                                                    

(a) Coenzymes                     

(b) Vitamins

(c) Co-factors                        

(d) Substrate

06: If non-protein part is loosely attached to protein, it is known as: (GJR-14,15,21)(RWP-17)

(a) Co-factor                         

(b) Coenzyme

(c) Holoenzyme                   

(d) Active site

07: If the non-protein part is covalently bonded, it is called: (SRG-15)(RWP-16)(SWL-18)(DGK-19)(MLT-21)

(a) Co-factor                         

(b) Activator

(c) Co-enzyme                     

(d) Prosthetic group

08: Coenzymes are closely related to: (MLT-16)(FSL-19)(LHR-22)(RWP-22)

(a) Amino acids                    

(b) Non-protein particles

(c) Vitamins                         

(d) Enzymes

09: The raw material from which coenzymes are made: (LHR-22)

(a) Proteins                           

(b) Nucleic acids

(c) Vitamins                         

(d) Carbohydrates

10: The vitamins are essential raw materials for the synthesis of: (SWL-14)(LHR-17)

(a) Activators                        

(b) Co-factors

(c) Coenzymes                     

(d) Prosthetic group

11: An activated enzyme consisting of a polypeptide chain and a co-factor is called: (SRG-15)(GJR-16)(MLT-18)(LHR-21)

(a) Apoenzyme                     

(b) Holoenzyme

(c) Coenzyme                      

(d) Both ‘a’ & ‘b’

12: An enzyme with its coenzyme or prosthetic group removed is called: (DGK-18)(FSL-21)

(a) Holoenzyme                   

(b) Apoenzyme

(c) Coenzyme                      

(d) Activator

13: Enzymes involved in respiration are found in: (MLT-14,16,21)(GJR-21)

(a) Chloroplasts                     

(b) Ribosomes

(c) Mitochondria                   

(d) Nucleus

14: Enzymes involved in photosynthesis are found in: (LHR-21)(DGK-21)

(a) Lysosomes                       

(b) Chloroplasts

(c) Leucoplasts                      

(d) Vacuoles

15: Enzymes that are integral part of ribosomes are responsible for the synthesis of: (RWP-16)

(a) Lipids                             

(b) Proteins

(c) Carbohydrates                  

(d) Nucleic acids

16: The enzymes which are involved in protein synthesis are integral part of: (SRG-19(SWL-21)(BWP-21)(AJK-21)

(a) Mitochondria                   

(b) Chloroplasts

(c) Ribosomes                      

(d) Nucleolus

17: The inactive form of enzyme pepsin is: (MLT-17)

(a) Holoenzyme                   

(b) Pepsinogen

(c) Apoenzyme                     

(d) None

18: Enzymes lower down the energy of: (FSL-22)

(a) Kinetic                            

(b) Activation

(c) Potential                         

(d) Ionic

19: The activation energy of the reaction is lowered by: (AJK-16)(BWP-16)

(a) Coenzyme                      

(b) Enzyme

(c) Substrate                         

(d) Product

20: An enzyme reacts only with its specific: (LHR-18)                                               

(a) Surface        

(b) Product        

(c) Substrate      

(d) Inhibitor

21: An enzyme and substrate react with each other through charge bearing sites called: (FSL-14)(GJR-22)

(a) Locus                              

(b) Centromere

(c) Active sites                      

(d) None

22: The catalytic activity of enzyme is restricted to a small portion of enzyme known as: (MLT-16)

(a) Active sites                      

(b) Catalytic site

(c) Binding site                     

(d) Reacting site

23: Lock and key model was proposed by: (FSL-14)(RWP-15)(MLT-19)

(a) Koshland                         

(b) Emil Fischer

(c) Fleming                          

(d) Watson

24: Emil Fischer proposed lock and key model in: (GJR-19)

(a) 1990           

(b) 1880           

(c) 1800           

(d) 1890

25: According to lock and key model, the active site is a: (LHR-15)(DGK-16)(AJK-17)(MLT-18)

(a) Soft structure                    

(b) Flexible structure

(c) Attractive structure           

(d) Rigid structure

26: Induced fit model was proposed by: (LHR-15,17)(SRG-16)

(a) Emil Fischer                     

(b) Koshland

(c) Jenner                             

(d) Pasteur

27: The rate of enzyme reaction becomes double for each _________ rise in temperature.

(a) 10oC            

(b) 15oC            

(c) 20oC            

(d) 25oC

28: The optimum temperature for human body enzyme is: (DGK-15)(LHR-16)(SWL-17)

(a) 27oC            

(b) 37oC            

(c) 47oC            

(d) 57oC

29: A little change in pH may lead to: (DGK-15)                                             

(a) Ionization of active sites of enzymes

(b) Ionization of substrate

(c) Retarding or even blocking of the enzyme activity

(d) Affects enzymes only in high concentration

30: Extreme changes in pH cause the bonds in enzyme to break, resulting in: (BWP-14)

(a) Activation of enzyme

(b) Inhibition of enzyme

(c) Denaturation of enzyme

(d) None of these

31: The optimum pH for enzyme pepsin is: (BWP-15,16)(LHR-16)(MLT-17)(FSL-17,18)(SWL-22)

(a) 2  

(b) 6.8

(c) 7  

(d) 9

32: Optimum pH for sucrase is: (BWP-14)(SRG-14,18)(DGK-18)

(a) 2.00            

(b) 4.50            

(c) 5.50            

(d) 7.60

33: The enzyme with optimum pH 5.50 is: (LHR-19)                                               

(a) Arginase                          

(b) Sucrase

(c) Pepsin                             

(d) Enterokinase

34: The optimum pH for enterokinase is: (SWL-16)                                             

(a) 1.50            

(b) 3.50            

(c) 5.50            

(d) 7.50

35: Salivary amylase works best at: (LHR-14)(DGK-16)(FSL-19)(AJK-19)

(a) 2.80            

(b) 4.80            

(c) 6.80            

(d) 8.80

36: The enzyme with optimum pH 7.6 is: (MLT-15)(BWP-19)

(a) Arginase                          

(b) Enterokinase

(c) Catalase                          

(d) Sucrase

37: The optimum pH of catalase is: (DGK-17)(RWP-17)(SWL-19)

(a) 6.60            

(b) 7.60            

(c) 8.60            

(d) 9.60

38: The optimum pH of pancreatic lipase is: (BWP-18)(LHR-15,18)(SRG-22)

(a) 7.00            

(b) 9.00            

(c) 8.00            

(d) 6.00

39: Optimum pH for enzyme arginase is: (BWP-17)(RWP-19)

(a) 7.60            

(b) 9.70            

(c) 6.40            

(d) 5.2

40: Poisons like cyanides, antibiotics and some drugs are examples of: (FSL-16)(GJR-18)(LHR-19)

(a) Enzymes                         

(b) Coenzymes

(c) Inhibitors                         

(d) Co-factors

41: The inhibitor which may destroy the globular structure of the enzyme is: (MLT-17)

(a) Competitive                    

(b) Non-competitive

(c) Reversible                       

(d) Irreversible

42: Irreversible inhibitors form which bonds with active sites? (MLT-19)

(a) Hydrogen bonds              

(b) Covalent bonds

(c) Ionic bonds                      

(d) Hydrophobic bonds

43: Reversible inhibitors form weak linkages with: (AJK-15,22)(SRG-16)(DGK-21)

(a) Reactant      

(b) Product        

(c) Substrate      

(d) Enzyme

44: Which inhibitors have structural resemblances with substrates? (RWP-21)

(a) Irreversible                      

(b) Competitive

(c) Non-competitive              

(d) Co-enzymes

45: The competitive inhibitor of succinic acid is: (GJR-17)(FSL-21)(MLT-22)

(a) Fumaric acid                    

(b) Malonic acid

(c) Citric acid                        

(d) Acetic acid

46: The product of succinic acid by the action of enzymes is: (LHR-14)

(a) Fumaric acid                    

(b) Malonic acid

(c) Citric acid                        

(d) Pyruvic acid


Q.01:  Define enzymes. Give an example. (AJK-15)(GJR-16)(SRG-18)(RWP-21)

Q.02:  What are enzymes and co-enzymes? (GJR-16)(MLT-17)

Q.03:  Define coenzyme. (MLT-19)

Q.04:  Why without enzymes, life is impossible? (SRG-22)

Q.05: What is co-factor? Give its significance. OR What are co-factors? Give their functions.


Q.06:  Why co-factors are necessary for proper functioning of enzymes? (RWP-22)

Q.07:  Why co-factors are considered necessary for enzyme action? (MLT-22)

Q.08:  What is activator? Give one example. (SWL-14)(DGK-18)(MLT-19)

Q.09:  Define co-factor and activator. (LHR-21)

Q.10:  Describe co-factor and co-enzyme. (LHR-21)

Q.11:  Differentiate between co-factor and activator. (RWP-16)(SRG-19)

Q.12:  Differentiate between co-factor and coenzyme. (AJK-16)(DGK-16)

Q.13:  Differentiate between activator and coenzyme. (SWL-18)

Q.14: Differentiate between prosthetic group and coenzyme.


Q.15: Differentiate between prosthetic group and activator. OR Define prosthetic group. (LHR-15,16,17)(SRG-16)(RWP-17)(FSL-19)(MLT-21)(BWP-21)

Q.16:  Why in human body vitamins are required in small quantity? (SRG-22)

Q.17:  Differentiate between apoenzyme and co-enzyme. (MLT-21)

Q.18:  Define apoenzyme. (GJR-21)

Q.19: What is holoenzyme? (LHR-14,15,16,17)(GJR-14,14,15)(BWP-15,18)(MLT-15,16,17)(DGK-17,17)(RWP-17)

Q.20:  Define apoenzyme and holoenzyme. (FSL-21)(BWP-21)

Q.21: Differentiate between apoenzyme and holoenzyme. (GJR-14,19)(LHR-14)(FSL-18,19)(MLT-18,18,19)(SRG-18)

Q.22:  Why apoenzyme is non-functional? (SRG-22)

Q.23:  What do you know about the distribution of enzymes in the cell? (FSL-15)

Q.24:  Why are enzymes considered as integral part of ribosomes? (GJR-22)


Q.25: Write down any four characteristics of enzymes. OR Write two properties of enzymes. (MLT-14,17)(BWP-14,15,16,17)(DGK-16)(LHR-16)(RWP-17,21)(SWL-19)(GJR-21)

Q.26: How is pepsinogen activated? OR Why some enzymes are produced in inactive form? Give example.                                                                (SRG-14)(SRG-16)(LHR-17)(RWP-17)(DGK-22)(SWL-22)

Q.27:  Why some enzymes are potentially damaging in their active forms? (MLT-22)           

Q.28: What is the difference between pepsin and pepsinogen? (SRG-14,15)(LHR-17)(RWP-17)(MLT-18)(FSL-19)


Q.29:  Write a note on active site of an enzyme. (RWP-15)(DGK-15)(SRG-16)(SWL-16)(MLT-19)(AJK-21)

Q.30:  Define active site and also give its two regions. (GJR-21)

Q.31:  Differentiate between substrate and active site. (LHR-18)

Q.32:  Differentiate between binding site and catalytic site. (MLT-18)(SWL-19)(FSL-21)

Q.33:  Give functions of the binding site and catalytic site of the active site of an enzyme. (FSL-18)

Q.34:  Why binding site and catalytic site are important for enzymes? (LHR-22)

Q.35:  Why is catalytic region of active site necessary to enzyme? (GJR-22)

Q.36:  How is enzyme-substrate complex formed? (LHR-19)(GJR-21)

Q.37:  What is enzyme to enzyme chain? (SWL-14)(SRG-16)(LHR-19)

Q.38:  How enzymes catalyse series of chemical reactions? (SRG-17)

Q.39:  Why some enzymatic reactions occur in series to form the final products? Explain briefly. (FSL-22)

Q.40:  Define feedback inhibition of enzymes with diagram. (LHR-18)

Q.41: What is lock and key model of enzyme action? Who proposed this model? (LHR-15,19,21)(MLT-15,17)(SRG-16,19)(BWP-17,19)(GJR-17)(RWP-17)(DGK-18,21)(SWL-18,21)(FSL-19)

Q.42: What is induce fit model of enzyme action? Who proposed this model? (SWL-14)(SRG-14,15)


Q.43:  Which model for enzyme substrate interaction is more supported? Discuss briefly that model. (FSL-22)

Q.44:  Why changes in enzyme structure are necessary for catalysis? (DGK-22)

Q.45:  How does an enzyme accelerate a metabolic reaction? (GJR-14,16,22)


Q.46:  Name the factors that affect the rate of enzyme action.

Q.47: What is the effect of enzyme concentration on the rate of reaction? (DGK-15,17,19)(SRG-16)(RWP-17)(GJR-17,18)(LHR-19)(MLT-19)

Q.48:  Why substrate concentration affects the rate of enzyme action? (MLT-22)

Q.49: If more enzymes are added in a system, its rate of reaction remains unchanged, why? (LHR-19)(MLT-19)

Q.50:  What is the effect of substrate concentration on the rate of enzyme action? (DGK-17)(MLT-17)(LHR-17)

Q.51:  At constant temperature and pH, how rate of reaction can be doubled? (LHR-22)

Q.52:  Why enzymes remain unaltered after the formation of products? (LHR-22)

Q.53:  What is optimum temperature of enzyme? (DGK-15,16)(AJK-16)(LHR-14,18)

Q.54:  How does temperature affect on enzyme activity? OR How do low and high temperatures affect enzyme activity? (LHR-16,17)(SWL-17)(MLT-14,17,18,18)(RWP-19)(BWP-19)(AJK-19)

Q.55:  What will happen to enzymatic reactions if the temperature becomes 50oC? (SWL-22)

Q.56:  What is optimum pH? Give one example. (LHR-15)(FSL-15,16)(BWP-16)(GJR-16)

Q.57:  Give optimum pH values of enzyme pepsin and pancreatic lipase. (SWL-16)

Q.58:  Why optimum pH is necessary for proper functioning of enzyme? (DGK-22)

Q.59:  Why enzymes need optimum pH for their proper functioning? Give one example. (FSL-22)

Q.60:  How does pH affect the rate of enzyme action? (MLT-15)(AJK-15)(RWP-16,19)(DGK-18)(LHR-18)

Q.61:  Why enzymes are affected by extreme changes in pH? (LHR-22)

Q.62: List two conditions that destroy enzymatic activity by disrupting bonds between the atoms in an enzyme.                                                                                    

Q.63: Enzymes become denatured in what ways? Explain briefly. (SWL-22)


Q.64:  Differentiate between enzymes and inhibitors. (SWL-21)

Q.65:  Define inhibitors. Give two examples. OR Define inhibitors of enzymes. (FSL-21)(DGK-21)(BWP-21)

Q.66: What are enzyme inhibitors? Give their major types.


Q.67:  Why inhibitors affect enzyme functions? Mention with examples. (LHR-22)

Q.68:  In which way, inhibitors stop catalytic activity of the enzymes? Give one example. (LHR-22)                      

Q.69:  Why poisons act as inhibitors? (RWP-22)

Q.70:  What are reversible inhibitors? (FSL-19)(LHR-21)

Q.71:  How can the effect of reversible inhibitors be neutralized? (RWP-22)

Q.72:  Define irreversible inhibitors. (RWP-21)(MLT-21)

Q.73:  How irreversible inhibitors inhibit enzyme activity? (RWP-16)(FSL-16)

Q.74: Differentiate between reversible and irreversible enzyme inhibitors. (BWP-14)(AJK-15,21)(GJR-15,16,19)(DGK-18)(SWL-21)

Q.75: What are competitive inhibitors? Why are they called reversible inhibitors? (FSL-19)(DGK-19)(MLT-21,21)

Q.76:  What are non-competitive inhibitors? (DGK-21)

Q.77: Compare competitive and non-competitive enzyme inhibitors. OR What are competitive and non-competitive inhibitors? (MLT-14,16,17)(GJR-14,18)(BWP-15,16,17,19)(SRG-15)(DGK-15,16)(RWP-17)(SWL-17)(LHR-17,18,21)



Q.1: Describe characteristics of enzymes. (BWP-14)


Q.2: Explain the mechanism of enzyme action in detail. (SRG-15)

Q.3: Explain how enzymes work in enzyme-to-enzyme chain or association? (SWL-15)                              


Q.4: With the help of diagrammatic representation, discuss the role of substrate concentration in an enzyme reaction. (MLT-14)


Q.5: Write a detailed note on inhibitors and its different types. (RWP-15)(GJR-16)

NOTE: Study and utilize this treasure of questions in your preparations. Also give your opinion in comments to improve this effort. Your verdict will have a meaning for us. Thanks a lot!

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