Biology Class 11 Chapter 3 Notes

• Our comprehensive Biology Class 11 Chapter 3 Notes will ensure you're fully prepared for your exams.
• Important Multiple Choice Questions for MDCAT Preparation from the chapter no 3 Enzymes class 11.
• List two conditions that destroy enzymatic activity by disrupting bonds between the atoms in an enzyme.
• How do low and high temperature, affect an enzyme activity?
• What is prosthetic group?
• Define inhibitors of enzyme.
• How does an enzyme accelerate a metabolic reaction?
• Differentiate between Enzyme and Coenzyme.
• Differentiate between Apoenzyme and Holoenzyme.
• Write down four characteristics of enzymes.
• What is active site of enzyme? Differentiate between binding site and catalytic site.
• Differentiate between Pepsin and Pepsinogen.
• Differentiate between Lock and Key model and Induced Fit model.
• Define the term Activator.
• How does enzyme concentration affect the rate of reaction?
• What is cofactor? Also give its significance.
• differentiate between Irreversible inhibiter and reversible inhibitor.
• Differentiate between Competitive and Non-Competitive Inhibitor.
• What do you mean by optimum pH for enzyme? Also give examples.
• Differentiate between Substrate and Active site.
• How enzymes catalyze series of chemical reaction?
• What is prosthetic group? Ans: Prosthetic group: If the non-protein part is covalently bonded, it is known as prosthetic group. Example: Haeme is an iron containing prosthetic group which acts as an electron carrier in cytochrome and oxygen carrier in hemoglobin and myoglobin.
• what are enzyme inhibitor. Ans: An inhibitor is a chemical substance that can react (in place of substrate) with the enzyme but it is not transformed into products and thus blocks the active site temporarily or permanently. Example: For example poisons, like cyanide, antibiotics, anti-metabolites and some drugs. 
• Differentiate between Competitive and Non Competitive Inhibitor. Competitive Inhibitor Competitive Inhibitor • They have structurally similarity with substrate. • They have not structurally similarity with substrate. • They may be selected by binding site but are not able to activate the catalytic site. • They form enzyme inhibitor complex other than active site. • They inactivate enzyme by blocking active site. • They inactivate enzyme by altering its globular structure. • Example: Malonic acid is competitive inhibitor of succinic acid. • Example: ATP is non-competitive inhibitor of phophofructokinase. 
• If more substrate to an already occurring enzymatic reaction is added, more enzyme activity is seen because:
• 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 their on either substrate or enzyme
• d) The enzyme substrate complex is probably failing to form during the reaction
• According to law and key model, the active site is:
• a) Attractive structure (Liquid)
• b) Flexible structure (Enzyme)
• c) Soft structure
• d) Rigid structure
• Which statement is incorrect about Lock and Key Model?
• a) Specific enzyme can transform only a specific substrate
• b) Active site of an enzyme is a non-flexible structure
• c) Active site does not change before during or even after the reaction
• d) t explains the mechanism of every chemical reaction
• If more substrate to already occurring enzymatic reaction is added more enzyme activity is seen because:
• 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.