Transcript Chemical Reactions and Enzymes

Chemical Reactions and Enzymes
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 – is a
process in which one or more
chemicals change into another
chemicals.
0 The chemicals (elements or
compounds) that enter into a
chemical reaction are the
reactants.
0 The chemicals (elements or
compounds) produced by a
chemical reaction are known as
products.
Energy in Reactions
0 Law of Conservation of Energy
0 Energy is neither created nor
destroyed, but it can be transferred or
transform from one form to another.
0 Chemical reactions that release energy
often occur spontaneously.
0 Chemical reactions that absorb
energy will not without a source of
energy.
Activation Energy
0 Do all reactions occur spontaneously?
0 If this were true what would happen
to your textbooks?
0 Will wood burn only if you light it
with a match?
0 Chemists call the energy that is
needed to get a reaction started the
activation energy
Activation Energy
0 Activation Energy
0 The minimum energy that must be input to a chemical
system in order for a chemical reaction to occur.
Enzymes
0 Some chemical reactions that make
life possible are too slow or have
activation energies that are too high
to make them practical for life.
0 These reactions require catalysts or
substances that speed up the rate of
a chemical reaction.
0 Enzymes work as catalysts by
lowering a reaction’s activation
energy, but without being changed
by the 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?
Activation Energy
0 What significance do these energy changes have
to do with living things?
In order to stay alive, organisms need to carry out
reactions that require energy.
Enzymes
0 Enzymes speed up chemical reactions that take
place in cells.
0 Enzymes are very specific, generally catalyzing
only one chemical reaction.
0 Lock and Key concept
0 One Enzyme can catalyze or speed up multiple
reactions
0 Enzymes are recyclable
Enzymes
0 For a chemical reaction to occur, the reactants must collide with
enough energy so that existing bonds will be broken and new
bonds will be formed.
0 Enzymes provide a place where reactants can be brought
together to react.
0 The reactants of enzyme – catalyzed reactions are known as
substrates.
The Enzyme/Substrate Complex
0 Each enzyme (protein) has a specific shape, the substrate binds
to the active site on the protein to help speed up the reaction.
0 AKA “lock and key”
0 Each enzyme has a specific active site for a specific substrate
Enzyme Videos
Short & basic enzyme animation
Digestive Enzyme Basics
Enzymes - In Summary
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
0 http://biologyca.blogspot.com/