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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
Activation Energy - Snowman
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.
Short & basic enzyme animation
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 (speed up) the same type of reaction
multiple times
0 Enzymes are recyclable
Enzyme Videos
Amoeba Sisters - Enzymes
Enzymes - In Summary
Digestive
Enzyme Basics
In your journal, list the major enzymes found within our
digestive system. Use page 934.
(Mouth-1, Stomach-1, Pancreas-3, Small Intestine-4)
Name
Name of
of Enzyme:
Enzyme:
Where
Where Found:
Found:
Pepsin
Stomach
Amylase
Pancreas/Intestine
Continue breaking down
starch
Trypsin
Pancreas/Intestine
Continues breaking down
protein
Lipase
Pancreas/Intestine
Breaks down fat
Maltase
Small Intestine
Sucrase
Small Intestine
Lactase
Small Intestine
Peptidase
Small Intestine
Salivary Amylase
Mouth
Function:
Function:
Break down starches
Break down proteins
Disaccharides into
monosaccharides
(complex sugar into simple)
Breaks proteins into Amino
Acids