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Enzymes: Structure and Function. Mr. Mah Living Environment 11/30/09. Warm-Up Quiz. What are the two differences between Active Transport and Passive Transport? Active Transport is Low Concentration to High Concentration Active Transport required energy (ATP)
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Enzymes: Structure and Function Mr. Mah Living Environment 11/30/09
Warm-Up Quiz • What are the two differences between Active Transport and Passive Transport? • Active Transport is Low Concentration to High Concentration • Active Transport required energy (ATP) • In the Sodium Potassium Pump, how many sodium (Na+) are pumped out and how many Potassium (K+) are taken in? • 3 Sodium (Na+) for 2 Potassium (K+)
Enzymes Enzymes are specialized proteins that regulate nearly every biochemical reaction in the cell. “-ase” = enzyme What does it mean to be specialized? To be specialized is to have a specific job. My house key only opens the door to my apartment. If enzymes are specialized, how many do you think we have in our bodies? A lot! Thousands, actually! Think about how many keys are needed to open all the doors in an apartment complex.
Enzymes work on substrates Substrates are the starting materials of biochemical reactions.
Different reactions require different enzymes Enzymes regulate: • Digestion (breaking down) • Synthesis (building up) • Cellular Respiration • Photosynthesis Enzymes are catalysts: they speed up chemical reactions without being used up or altered (changed) Without enzymes, biochemical reactions would occur too slowly to sustain life
What determines if the substrate will fit into the active site? Second Third First The SHAPE!! Each enzyme must have a specific shape to work correctly.
What affects shape? Environmental conditions such as temperature and pH will change an enzyme’s shape and can either speed up or slow down its rate of function. Enzymes stop working when conditions are not at optimal conditions! Optimal: ideal or best Need optimal temperatures and optimal pH
Effects on Enzyme Activity • Rate of Enzyme Activity is influenced by: • Temperature (higher temperature = more activity until the enzyme’s protein denatures) • Denatures: changes shape
Effects on Enzyme Activity • Rate of Enzyme Activity is influenced by: • pH (usually in the range of 6-8 for humans) Basic Acidic