Download Enzymes

Enzymes
Enzymes are…
• Catalysts
– is any substance that works to accelerate a
chemical reaction
• Most enzymes are proteins
How do catalysts speed up reactions?
• The activation energy in chemistry is the
energy needed by a system to initiate a
particular process
• Catalysts decrease activation energy
Lock and Key model
Active Site
• Substrate: substance that
an enzyme reacts with
• Active Site: part of the
enzyme that reacts or
binds to the substrate
Enzyme-Substrate Complex
Enzymes are specific and
Complementary
• Complementary: complement one another;
shaped for precise pairing
• Specific: particular, precise
– Only the correct substrate can fit into the
enzyme’s active site
Enzymes end in -ase
• Carbohydrase- breaks down carbohydrates
into simple sugars
• Amylase- breaks down starch
• Protease – breaks down proteins into amino
acids
• Lipase- breaks down lipids into fatty acids and
glycerol
Digestive End products
Macromolecule
Digestive End Product
Carbohydrate
Simple Sugar
Protein
Amino Acids
Lipid
3 fatty acids and glycerol
Nucleic Acid
Nucleotide
Temperature effects enzymes
• Increasing
temperature
increases enzyme
activity until it
reaches an optimum
value
• Increasing
temperature past
that point denatures
the enzyme
Denature
• shape of the protein is altered through some
form of external stress
• will no longer be able to carry out its cellular
function
pH effects enzymes
• Certain pH value
causes optimal
enzyme activity
• Too low or too
high pH will
denature the
enzyme
Enzymes are reused or recycled
• In a written equation, enzymes appear on
both the reactant and product side
• Substrate + enzyme enzyme and products
reactants
products
• They are not used up
• They are recycled and being used over and
over gain
• The function of most proteins depends
primarily on the
(1) type and order of amino acids
(2) environment of the organism
(3) availability of starch molecules
(4) nutritional habits of the organism
• Enzyme molecules normally interact with
substrate molecules. Some medicines work by
blocking enzyme activity in pathogens. These
medicines are effective because they
(1) are the same size as the enzyme
(2) are the same size as the substrate molecules
(3) have a shape that fits into the enzyme
(4) have a shape that fits into all cell receptors
• The diagram below represents two molecules
that can interact with each other to cause a
biochemical process to occur in a cell.
Molecules A and B most likely represent
(1) a protein and a chromosome
(2) a receptor and a substrate
(3) a carbohydrate and an amino acid
(4) an antibody and a hormone