Download - Enzymes
Enzymes
EnzymesOProteinOOnly act on certain substances called substrates
FunctionsOIncreases the rate at which molecules in the body are built or broken down
OThey are catalysts; They speed up reactions
OEven though enzymes speed up reactions, they are NOT changed during the reactionOSo enzymes are
reusable
FunctionsOPlay roles in other parts of the body OMyosin: important in muscle contraction
Enzymes at Work1. An enzyme and a substrate are in the same area.
2. The enzyme grabs on to the substrate at a special area called the active site.
Enzymes at Work3. A process called catalysis happens. Catalysis is when the substrate is changed.
4. The enzyme lets go, and returns to normal, ready to work on another molecule of substrate. The substrate is no longer the same. It is now called the product
Enzyme VideoO http://highered.mcgraw-hill.com/sites
/0072495855/student_view0/chapter2/animation__how_enzymes_work.html
Factors that Affect EnzymesOTemperature-
as temperature increases, enzyme activity increasesO However
extremely high temperatures cause enzyme activity to stop
Factors that affect Enzymes
OpH-extremely high or low causes enzymes to stop working
Factors that affect EnzymesOInhibition
OCompetitive: enzyme is inhibited by an inactive substrate, or competitor, so called because it competes with the real substrate for the active site
OFeedback: an inhibitor binds to a different site of an enzyme, deactivating it
InhibitorsFeedback
GroupsOThe two main groups are:
OMetabolic: all chemical reactions that take place in a living cell
ODigestive: related to breaking down food for absorption
Digestive EnzymesOLipase: breaks down fatOProtease: breaks down proteinOCellulase: breaks down fiber; herbivores have
OAmylase: starts breaking down starches; starts chemical part of digestion
Digestive EnzymesOLactase: breaks down dairy
OSucrase: breaks down sugar
OMaltase: breaks down grainOAll of these enzymes are secreted by mucosal cells that line your small intestine
ImportanceOWithout enzymes our body would not function properly; there are several disorders related to lack of or improper enzymes
Importance-exampleODisease called
PhenylketonuriaOBorn with a mutation that leads
to a mutation in the enzyme needed to break down the amino acid phenylalanine
O If left untreated this could lead to mental retardation