Chemical Reactions and Enzymes
0 As we have seen, living things are made of chemical compounds (Biomolecules),
but more importantly chemistry isn’t just what life is made of, chemistry is also
what life does.
Chemical Reactions
0 Chemical reaction – Change of
substances into different ones by
breaking and forming of chemical
bonds.
0 The chemicals that start a chemical
reaction are the reactants.
0 The chemicals produced by a
chemical reaction are called
products.
Energy in Reactions
0 Activation energy is the amount of energy that needs
to be absorbed to start a chemical reaction.
Two paths will take you to the same end
location. Which one will take less energy to get
there and will happen faster?
0 Catalysts are substances that speed up chemical reactions.
0 decrease activation energy
0 increase reaction rate
Enzymes
0 Enzymes are special proteins in living
organisms that work as catalysts.
0 Enzymes function best in a small
range of conditions.
0 Changes in temperature or pH (acidity)
can damage (denature) enzyme structure.
0 An enzyme’s function depends on its
structure.
0 An enzyme’s structure allows only certain reactants to bind to
the enzyme.
– Substrates (reactants)
– Active site (location of reaction on enzyme)
substrates
(reactants)
Substrate binds to the active site on the enzyme.
AKA “lock and key”
enzyme
Substrates bind to an
enzyme at certain places
called active sites.
Substrates bind to an
enzyme at certain
places called active
sites.
The enzyme brings
substrates together
and weakens their
bonds.
The catalyzed reaction forms
a product that is released
from the enzyme.
Enzymes
0 Enzymes speed up chemical reactions that take place in cells.
0 Enzymes are very specific, catalyzing only one chemical reaction.
0 Lock and Key concept
0 One Enzyme can catalyze or speed up multiple reactions
0 Enzymes are recyclable
Enzyme Videos
Short & basic enzyme animation
Enzymes - In Summary
Activation Energy - Snowman
How Enzymes Work
Digestive Enzyme Basics
Enzyme Function
In your journal, list the major enzymes found within our
digestive system. Use pages 978-984.
(Mouth-1, Stomach-1, Pancreas-3, Small Intestine-4)
Name
Enzyme: Where
Found:
Name of
of Enzyme:
Where Found:
Salivary Amylase
Mouth
Function:
Function:
Pepsin
Stomach
Break down proteins
Amylase
Pancreas
Continue breaking
down starch
Trypsin
Pancreas
Continues breaking
down protein
Lipase
Pancreas
Breaks down fat
Maltase
Small Intestine
Sucrase
Small Intestine
Lactase
Small Intestine
Peptidase
Small Intestine
Break down starches
Disaccharides into
monosaccharides
Dipeptides into Amino
Acids