Slide 1: Introduction

  • Chemistry in everyday life
  • Importance of enzymes in our body
  • Role of enzymes in various biological processes

Slide 2: What are Enzymes?

  • Enzymes are biological catalysts
  • They are protein molecules
  • Specific for particular reactions
  • They increase the rate of reactions

Slide 3: Structure of Enzymes

  • Primary, secondary, tertiary, and quaternary structure
  • Active sites and substrate binding
  • Enzyme-substrate complex formation

Slide 4: Enzyme Substrate Specificity

  • Enzymes are highly specific
  • Enzyme fits specifically to the substrate
  • Lock and key model
  • Induced fit model

Slide 5: Enzyme Action - Step 1

  • Binding of substrate to the active site
  • Formation of enzyme-substrate complex

Slide 6: Enzyme Action - Step 2

  • Conversion of substrate to product
  • Enzyme provides an alternative pathway
  • Activation energy and lowering it

Slide 7: Factors Affecting Enzyme Activity

  • Temperature
  • pH
  • Substrate concentration
  • Enzyme concentration

Slide 8: Inhibition of Enzymes

  • Competitive inhibition
  • Non-competitive inhibition
  • Reversible and irreversible inhibition

Slide 9: Classification of Enzymes

  • Oxidoreductases
    • Example: Alcohol dehydrogenase
  • Transferases
    • Example: Kinases
  • Hydrolases
    • Example: Lipase
  • Lyases
    • Example: Pyruvate decarboxylase

Slide 10: Enzymes and their Applications

  • Industrial applications
    • Production of antibiotics
    • Food processing
  • Medical applications
    • Enzyme replacement therapy
    • Diagnostic assays and kits
  • Environmental applications
    • Bioremediation
    • Waste water treatment
  1. Chemistry in everyday life - How Enzymes Work
  • Enzymes play a crucial role in various biological processes
  • They speed up chemical reactions within our bodies
  • Enzymes work by lowering the activation energy required for a reaction to occur
  • They do not get consumed or altered during the reaction
  • Enzymes are highly specific, each one catalyzing a specific reaction
  1. Enzyme examples in everyday life
  • Digestive enzymes: Amylase in saliva, pepsin in stomach for digestion
  • Cleaning products: Proteases remove protein stains, lipases remove grease stains
  • Baking: Amylase breaks down starch into sugar, yeast produces enzymes for fermentation
  • Medical industry: Enzymes used in diagnostic tests, production of pharmaceuticals
  1. Enzyme kinetics
  • Substrate concentration affects the rate of enzyme action
  • At low substrate concentration, the reaction rate is directly proportional to the substrate concentration
  • At high substrate concentration, the reaction rate reaches a maximum (Vmax)
  • Michaelis-Menten equation: v = (Vmax*[S])/(Km + [S])
  1. Enzyme specificity and efficiency
  • Enzyme-substrate specificity arises from the complementary shape and chemical properties
  • Enzymes can show high catalytic efficiency even at low concentrations
  • Enzyme efficiency can be measured by turnover number (kcat)
  • kcat = Vmax/[E]
  1. Enzyme cofactors and coenzymes
  • Some enzymes require additional non-protein molecules called cofactors
  • Cofactors can be inorganic ions like Zn2+ or organic molecules called coenzymes
  • Coenzymes can be derived from vitamins, such as NAD+ and FAD
  • Cofactors and coenzymes aid in the enzyme-substrate binding and catalytic activity
  1. Enzyme inhibition
  • Competitive inhibition: Inhibitor competes with the substrate for the active site
  • Non-competitive inhibition: Inhibitor binds to a different site, altering the enzyme’s shape or function
  • Reversible inhibition can be overcome, while irreversible inhibition cannot
  • Enzyme inhibitors are often used in medications or pesticides
  1. Factors influencing enzyme activity
  • Temperature: Optimum temperature promotes enzyme activity, extreme temperatures denature enzymes
  • pH: Each enzyme has an optimal pH at which it functions best
  • Enzyme concentration: Increasing enzyme concentration can increase the reaction rate, up to a certain point
  • Substrate concentration: Increasing substrate concentration can increase the reaction rate, but with limitations
  1. Enzyme regulation
  • Allosteric regulation: An effector molecule binds to a site other than the active site, influencing enzyme activity
  • Feedback inhibition: End product of a metabolic pathway inhibits an earlier enzyme in the pathway
  • Covalent modification: Addition of a chemical group to the enzyme can activate or inhibit its activity
  • Gene regulation: Controlling the synthesis of enzymes through gene expression
  1. Enzymes as drug targets
  • Enzymes involved in disease-related processes can be targeted with drugs
  • Inhibitors or activators can modulate enzyme activity to restore normal function
  • Understanding enzyme structure and function aids in designing effective drugs
  • Examples include enzyme inhibitors for cancer treatment or enzyme replacement therapy
  1. Conclusion
  • Enzymes are essential for life processes, both in the human body and in various industries
  • Their specific and efficient catalytic activity enables biochemical reactions to occur
  • Further research on enzymes can lead to breakthroughs in medicine, agriculture, and environmental applications
  • Understanding enzyme kinetics and regulation is crucial for the development of new therapies and technologies

Slide s 21 to 30

  1. Enzyme kinetics - Michaelis-Menten equation:
  • v = (Vmax*[S])/(Km + [S])
  • v: reaction rate
  • Vmax: maximum reaction rate at saturating substrate concentration
  • [S]: substrate concentration
  • Km: Michaelis constant, substrate concentration at half-maximal velocity
  1. Enzyme kinetics - Lineweaver-Burk plot:
  • Double reciprocal plot of the Michaelis-Menten equation
  • Linearizes the data to determine Km and Vmax
  1. Enzyme inhibitors - Competitive inhibition:
  • Inhibitor competes with the substrate for the active site
  • Increases apparent Km, but Vmax remains unchanged
  • Example: Statins inhibit HMG-CoA reductase in cholesterol synthesis
  1. Enzyme inhibitors - Non-competitive inhibition:
  • Inhibitor binds to a different site than the active site
  • Alters enzyme conformation, reducing catalytic efficiency
  • Both Km and Vmax are affected
  • Example: Aspirin inhibits cyclooxygenase in prostaglandin synthesis
  1. Enzyme inhibitors - Reversible inhibition:
  • Binding between inhibitor and enzyme is non-covalent
  • Reversible inhibitors can dissociate from the enzyme
  • Example: ACE inhibitors used for blood pressure control
  1. Enzyme inhibitors - Irreversible inhibition:
  • Binding between inhibitor and enzyme is covalent
  • Irreversible inhibitors permanently inactivate the enzyme
  • Example: Nerve gases inhibit acetylcholinesterase
  1. Enzyme cofactors - Metal ions:
  • Metal ions like Zn2+, Mn2+, or Fe3+ play essential roles in enzyme catalysis
  • Help in substrate binding or participate in redox reactions
  • Example: Carbonic anhydrase requires Zn2+ for its activity
  1. Enzyme cofactors - Coenzymes:
  • Organic molecules derived from vitamins
  • Act as carriers of specific functional groups during catalysis
  • Example: NAD+ and FAD in redox reactions
  1. Enzyme regulation - Allosteric regulation:
  • Binding of an effector molecule to a site other than the active site
  • Can activate or inhibit enzyme activity by inducing conformational changes
  • Example: Allosteric inhibition of phosphofructokinase in glycolysis
  1. Enzyme regulation - Feedback inhibition:

  • End product of a metabolic pathway inhibits an earlier enzyme in the pathway

  • Maintains homeostasis and prevents overproduction

  • Example: Threonine deaminase inhibited by isoleucine in the synthesis of isoleucine