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Enzymes
Ch 2.4
SB1- Relationship between Structure and
Function in Cells
All Enzymes are Proteins
• … but not all proteins are enzymes
SB1- Relationship between Structure and
Function in Cells
Protein Structure
• http://www.youtube.com/watch?v=lijQ3a8yU
YQ
SB1- Relationship between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.2 Chemical Reactions
Reactions
 A physical reaction does not
produce a new substance, but
involves a change in the state of
matter.
 Ex: crushing a can, melting
an ice cube.
 A chemical reaction is the
process by which atoms or
groups of atoms in substances
are reorganized into different
substances.
 Ex: rusting, combustion
(burning), cooking an egg
Chemical reaction
Physical reaction
Chapter 6
Chemistry in Biology
6.2 Chemical Reactions
Chemical Equations
 Chemical equations describe the substances in the
reaction and arrows indicate the process of change.
 Reactants are the starting substances, on the left
side of the arrow.
 Products are the substances formed during the
reaction, on the right side of the arrow.
SB1- Relationship between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.2 Chemical Reactions
 Example reaction:
Glucose and oxygen react to form carbon
dioxide and water.
Critical thinking: What biochemical process does
this chemical equation represent???
C6H12O6 + 6O2  6C02 + 6H20
SB1- Relationship between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.2 Chemical Reactions
Energy of Reactions
 Energy diagrams
illustrate the progress
and available energy
of a chemical reaction.
 The activation energy
is the minimum
amount of energy
needed for reactants
to form products in a
chemical reaction.
SB1- Relationship between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.2 Chemical Reactions
Energy of Reactions
 All chemical reactions
either take in energy or
release energy.
 Exothermic reactions:
release heat energy.
 Endothermic reactions:
absorbs heat energy.
SB1- Relationship between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.2 Chemical Reactions
 This reaction is
exothermic and
released heat energy.
 The energy of the
product is lower than
the energy of the
reactants.
SB1- Relationship between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.2 Chemical Reactions
 This reaction is
endothermic and
absorbed heat energy.
 The energy of the
products is higher
than the energy of
the reactants.
SB1- Relationship between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.2 Chemical Reactions
Enzymes
 Enzymes are special proteins
that help to speed up
chemical reactions by acting
as catalyst and lessening the
activation energy.
SB1- Relationship between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.2 Chemical Reactions
Enzymes
 A catalyst is a substance
that lowers the activation
energy needed to start a
chemical reaction.
 It does not increase how
much product is made and it does not get used
up in the reaction.
 Enzymes are biological catalysts.
SB1- Relationship between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.2 Chemical Reactions
Enzymes
 Enzymes are biological
catalysts that speed up
reactions in living
organisms.
 Enzymes used for:
 Photosynthesis
 Cell Respiration
 Growth
 Waste removal
 DNA replication
between Structure and
 Movement SB1- Relationship
Function in Cells
Chapter 6
Chemistry in Biology
6.2 Chemical Reactions- How do they Work???
 The substance acted upon by the enzyme is called the
substrate.
 The specific location where a substrate binds on an
enzyme is called the active site.
Fits together like a lock and key
SB1- Relationship between Structure and
Function in Cells
Enzymes in Action
http://www.lpscience.fatcow.com/jwanamaker/
animations/Enzyme%20activity.html
SB1- Relationship between Structure and
Function in Cells
macromolecule
types
elements
Compounds in Living Things
Monomer
(building
blocks)
functions
Carbohydrates
-Simple (sugars)
Carbohydrates
- Complex
Lipids
Proteins
Nucleic Acids
Water (not a
macromolecule)
SB1- Relationship between Structure and
Function in Cells
examples
macromolecule
types
Carbohydrates
-Simple (sugars)
Monosac
charides
Disacchar
ides
elem
ents
Compounds in Living Things
Monomer
(building blocks)
functions
examples
C,H,O
Monosaccharides
Quick energy
Glucose
Sucrose
Lactose
Fructose
Long term energy
Plants use these to store
energy
Starch
Cellulose
Fiber
(simple sugars)
Carbohydrates
-Complex
Lipids
Fats
Oils
waxes
C,H
Fatty acids
Store most energy
Insulation and protection
Water proof (cell membrane)
Sat. fats,Unsat.,
Polyunsaturated
Steroids
cholesterol
Proteins
Enzymes
and many
others
C,H,O,
N,(S)
Amino acids
(20)
Enzymes speed chem. Rxs.
Building blocks
Transport materials
Over 10,000
Nucleic Acids
DNA, RNA
C,H,O,
N,P
nucleotides
Genetic material that contains
instructions for making
proteins
DNA
RNA
Water
(not a
macromolecule)
H,
O
Site of most chem rxs. in cells
Dissolves most substances
Insulates from rapid temp.
changes.
Chapter 6
Chemistry in Biology
6.4 The Building Blocks of Life
Organic Chemistry
 The study of all
compounds containing the
element CARBON
SB1- Relationship Between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.4 The Building Blocks of Life
 Carbon compounds can be in the shape of straight
chains, branched chains, and rings.
SB1- Relationship Between Structure and
Function in Cells
What is a macromolecule?
 A giant molecule made up of
100’s or 1000’s or smaller units
called MONOMERS
Monomers link together to form
large POLYMERS
SB1- Relationship Between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.4 The Building Blocks of Life
Macromolecules
 Carbon atoms can be joined to form carbon
molecules.
 Macromolecules are large molecules formed by
joining smaller organic molecules together.
 Polymers are molecules made from repeating
units of identical or nearly identical compounds
linked together by a series of covalent bonds.
SB1- Relationship Between Structure and
Function in Cells
The 4 types of macromolecules:
CARBOHYDRATES
NUCLEIC ACIDS
PROTEINS
LIPIDS
SB1- Relationship Between Structure and
Function in Cells
CARBOHYDRATES
 Made up of C,H,O
Made by plants
Simple carbs:
• Function quick source of energy
• Types: Monosaccharide-simple sugar, disaccharide-2,
polysaccharide-many
• Ex: glucose, lactose, fructose, sucrose
Complex Carbs
Monomer: monosaccharides (simple sugars)
Types:
SB1- Relationship Between Structure and
Function in Cells
Figure 2-13 A Starch
Section 2-3
Starch
Glucose
Go to
Section:
SB1- Relationship Between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.4 The Building Blocks of Life
Lipids
 Made mostly of carbon and hydrogen
 A triglyceride is a fat if it is solid at room
temperature and an oil if it is liquid at room
temperature.
SB1- Relationship Between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
LIPIDS
Examples
 saturated fats: have tail chains with only single
bonds
 unsaturated fats: have at least one double bond
in the tail chain
 polyunsaturated fats: more than one double
bond in the tail
SB1- Relationship Between Structure and
Function in Cells
LIPIDS
 Elements: Made up mainly
of C & H
Functions:
store largest amounts of
energy,
insulation & protection
Water proof (cell
membrane)
SB1- Relationship Between Structure and
Function in Cells
LIPIDS
Functions
•
store large amts. Of energy
•
insulation and protection
•
water proof (cell membrane)
SB1- Relationship between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.4 The Building Blocks of Life
Proteins
 A compound made of small carbon compounds
called amino acids
 Amino acids are small compounds that are
made of carbon, nitrogen, oxygen, hydrogen,
and sometimes sulfur.
SB1- Relationship Between Structure and
Function in Cells
PROTEINS
 Made up of C,H,O,N
Made up of groups called amino
acids (20 in nature)
 proteins have a large variety of
sizes & shapes
If the shape changes, it becomes a
new protein
Ex: when you boil an egg, the
protein changes color, shape
Found in muscles, cell membrane
SB1- Relationship Between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.4 The Building Blocks of Life
 ENZYMES are special kinds of proteins that speed up
chemical reactions
 The number and the order in which the amino acids are
joined define the protein’s primary structure.
 After an amino acid chain is formed, it folds into a unique
three-dimensional shape, which is the protein’s secondary
structure, such as a helix or a pleat.
SB1- Relationship Between Structure and
Function in Cells
Chapter 6
Chemistry in Biology
6.4 The Building Blocks of Life
 Nucleic acids are complex macromolecules that store
and transmit genetic information.
 Nucleic acids are made of smaller repeating subunits
called nucleotides, composed of carbon, nitrogen,
oxygen, phosphorus, and hydrogen atoms.
SB1- Relationship Between Structure and
Function in Cells
Nucleic Acids
 Made up of H,O,N,C & P
 Store and transmit genetic
information
 Made up of nucleotides
 Two types: DNA & RNA
SB1- Relationship Between Structure and
Function in Cells