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Enzymes. Chapter 8. Learning Targets. I can describe the structure and explain the significance and functions of enzymes in biological systems I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction.
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Enzymes Chapter 8
Learning Targets • I can describe the structure and explain the significance and functions of enzymes in biological systems • I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction. • I can explain how enzymes speed up chemical reactions. • I can explain the interactions between substrates and active sites of enzymes. • I can explain how the following affect enzymatic function: • Enzyme and substrate concentrations • pH, temperature and salinity • coenzymes • inhibition; competitive, non-competitive and allosteric cooperativity • I can describe the role that enzymes play in feedback inhibition. • I can design a lab that quantifiably measures the effect of an environmental factor on enzymatic activity.
Structure • Protein • Each enzyme is substrate-specific: the active site is specifically shaped so only certain molecules fit on it
Learning Targets • I can describe the structure and explain the significance and functions of enzymes in biological systems • I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction. • I can explain how enzymes speed up chemical reactions. • I can explain the interactions between substrates and active sites of enzymes. • I can explain how the following affect enzymatic function: • Enzyme and substrate concentrations • pH, temperature and salinity • coenzymes • inhibition; competitive, non-competitive and allosteric cooperativity • I can describe the role that enzymes play in feedback inhibition. • I can design a lab that quantifiably measures the effect of an environmental factor on enzymatic activity.
Activation Energy • How reactions work:
Learning Targets • I can describe the structure and explain the significance and functions of enzymes in biological systems • I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction. • I can explain how enzymes speed up chemical reactions. • I can explain the interactions between substrates and active sites of enzymes. • I can explain how the following affect enzymatic function: • Enzyme and substrate concentrations • pH, temperature and salinity • coenzymes • inhibition; competitive, non-competitive and allosteric cooperativity • I can describe the role that enzymes play in feedback inhibition. • I can design a lab that quantifiably measures the effect of an environmental factor on enzymatic activity.
Induced Fit • Shape of active site can change slightly as substrate binds • The active site is then molded into a precise conformation--sort of like a hand in a glove • So, some enzymes canact on similarmolecules, not justspecificones
Learning Targets • I can describe the structure and explain the significance and functions of enzymes in biological systems • I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction. • I can explain how enzymes speed up chemical reactions. • I can explain the interactions between substrates and active sites of enzymes. • I can explain how the following affect enzymatic function: • Enzyme and substrate concentrations • pH, temperature and salinity • coenzymes • inhibition; competitive, non-competitive and allosteric cooperativity • I can describe the role that enzymes play in feedback inhibition. • I can design a lab that quantifiably measures the effect of an environmental factor on enzymatic activity.
Enzyme-Substrate Interaction • How do the following relate to enzymes? • active site • substrate • induced fit • energy of activation
Learning Targets • I can describe the structure and explain the significance and functions of enzymes in biological systems • I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction. • I can explain how enzymes speed up chemical reactions. • I can explain the interactions between substrates and active sites of enzymes. • I can explain how the following affect enzymatic function: • Enzyme and substrate concentrations • pH, temperature and salinity • coenzymes • inhibition; competitive, non-competitive and allosteric cooperativity • I can describe the role that enzymes play in feedback inhibition. • I can design a lab that quantifiably measures the effect of an environmental factor on enzymatic activity.
Enzyme-Substrate Concentration • Enzymes act on one molecule at a time • Reach a saturation point when all enzymes are engaged in reaction
pH, Temperature, Salinity • All enzymes have a specific range for optimal performance • Outside of that range denature don’t function
Inhibiting Factors Prevent/Interfere with Enzyme Function
Competitive Inhibition • Competitive inhibitor has same shape as substrate • (competes for active site) • Prevents substrate from binding to active site by binding to active site itself
Allosteric Inhibition • Inhibitor binds to allosteric site of enzyme • Active site changes shape, no substrate binds
Enhancing Factors Help/Increase Enzyme Function
Cofactors & Coenzymes • Cofactor assist with catalytic activities of enzyme • Coenzyme is an organic cofactor • Ex: vitamins
Allosteric Activation • Change in the enzyme’s shape due to binding of activator at allosteric site • Enzyme is stabilized by activator
Allosteric Cooperativity • One substrate molecule primes an enzyme to receive more substrates readily • Ex: hemoglobin
Learning Targets • I can describe the structure and explain the significance and functions of enzymes in biological systems • I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction. • I can explain how enzymes speed up chemical reactions. • I can explain the interactions between substrates and active sites of enzymes. • I can explain how the following affect enzymatic function: • Enzyme and substrate concentrations • pH, temperature and salinity • coenzymes • inhibition; competitive, non-competitive and allosteric cooperativity • I can describe the role that enzymes play in feedback inhibition. • I can design a lab that quantifiably measures the effect of an environmental factor on enzymatic activity.
Feedback Inhibition • The switching off of a biochemical pathway by the product of the pathway • Negative feedback • Conserve energy!
Learning Targets • I can describe the structure and explain the significance and functions of enzymes in biological systems • I can describe why an investment of activation energy is necessary to initiate a spontaneous reaction. • I can explain how enzymes speed up chemical reactions. • I can explain the interactions between substrates and active sites of enzymes. • I can explain how the following affect enzymatic function: • Enzyme and substrate concentrations • pH, temperature and salinity • coenzymes • inhibition; competitive, non-competitive and allosteric cooperativity • I can describe the role that enzymes play in feedback inhibition. • I can design a lab that quantifiably measures the effect of an environmental factor on enzymatic activity.
AP Lab 13 • Bozeman video