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U1 LE6: For Further Study Metabolic Managers. Enzymes. 1. Enzymes are proteins. They are built by organisms from the nutrients or biomolecules they take in Enzymes frequently end with the suffix “-ase” amylase, lactase, cellulase, sucrase.
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1. Enzymes are proteins • They are built by organisms from the nutrients or biomolecules they take in • Enzymes frequently end with the suffix “-ase” amylase, lactase, cellulase, sucrase
Each lock requires it’s own keyEvery chemical reaction has it’s own enzyme
2. Every chemical reaction requires its own enzyme • Amylase - breaks down starch • Sucrase – breaks down sucrose • Lactase – breaks down lactose • Lipase – breaks down fats • Polymerase – Builds nucleic acids (DNA or RNA) from nucleotides • Helicase – Unwinds the DNA strand
Is this enzyme performing catabolism or anabolism? Enzyme Reactant + Reactant -----------> Product
3. Enzymes have specific shapes Enzymes can fold into different shapes based on the number of amino acids, the type of amino acids, the sequence of amino acids. Ex. Analogy • 26 letters of the alphabet 20 amino acids • Form different words Form different proteins • Ex. Ship vs. shipmate – different number and type • Ex. Ship vs. Hips – different sequence
Enzymes have specific shapes • Lactase is an enzyme that breaks down the disaccharide lactose into glucose and galactose • Only the molecule of lactose will fit into this enzyme • Catabolic or Anabolic reaction? • chemicalconnection.org.uk
Enzymes shapes can be very complex . . this is a diagram of lactase folded www.10jahresib.ethz.ch/.../educational.html
4. Enzymes catalyze or increase the rate of reactions • Enzymes speed up reactions by a million times • It would take 50 years to digest one meal without enzymes • Life could not exist without enzymes, because metabolism would come to a screeching halt
5. Enzymes speed up reactions by decreasing the amount of energy needed • Enzymes speed up reactions by decreasing the amount of energy needed to start the reaction • student.ccbcmd.edu
High temperatures Destroy the shape of enzymes – they can’t do their job Metabolic process cannot occur This is why heat stroke can kill you 7A. Enzyme Destruction:Temperature can change it’s shape or denature the enzyme http://www.a2gov.org/government/safetyservices/emergencymanagement/PublishingImages/Heat%20Exhaustion%202.gif
Effect of Temperature on Enzyme Reaction Rate The rate of enzyme catalyzed reactions will increase with increasing temperature (due to an increase of molecule collisions) until an optimum temperature is reached. Above the optimum temperature the enzyme changes shape and is denatured (destroyed).
Blood pH 7 – 7.45 Stomach pH 1-4 Intestine pH 8 Mouth pH 6.7-7 An improper pH can destroy enzymes Enzymes that work in specific parts of the body, need to work at a specific pH 7B. Enzyme Destruction:pH can change it’s shape or denature the enzyme
Effect of pH on Enzyme Reaction Rate Pepsin is an enzyme in the stomach and as a pH optimum of about 1.5. Salivary amylase and alakaline phosphatase have pH optima of 6 and 9 respectively.
Enzyme Review… 1. Biomolecule Group: Proteins2. Every reaction has its own enzyme3. Enzymes have specific shapes (based on amino acids)4. Catalyze or speed up reactions5. Increase the rate of reactions bydecreasing the amount of energy needed6. Enzymes can be reused for more reactions7. High temperatures,salinity, or pH can destroy or denature (change its shape)