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
- 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
- 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
- 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])
- 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]
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- Enzyme kinetics - Lineweaver-Burk plot:
- Double reciprocal plot of the Michaelis-Menten equation
- Linearizes the data to determine Km and Vmax
- 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
- 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
- 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
- Enzyme inhibitors - Irreversible inhibition:
- Binding between inhibitor and enzyme is covalent
- Irreversible inhibitors permanently inactivate the enzyme
- Example: Nerve gases inhibit acetylcholinesterase
- 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
- Enzyme cofactors - Coenzymes:
- Organic molecules derived from vitamins
- Act as carriers of specific functional groups during catalysis
- Example: NAD+ and FAD in redox reactions
- 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
- 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
Slide 1: Introduction Chemistry in everyday life Importance of enzymes in our body Role of enzymes in various biological processes