Macromolecules
Two types of reactions
Monomers and Polymers
Overview of Carbohydrates
Overview of Lipids
Overview of Proteins
Overview of Nucleic Acids
Organic Macromolecules
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Four Groups:
Carbohydrates
Lipids
Proteins
Nucleic Acids
Reactions in Living Things
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Catabolic Reactions:
Those that break macromolecules
into smaller molecules and release
energy in the process.
Anabolic Reactions
Those that make smaller molecules
into macromolecules and use energy in
the process.
Monomers
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Small or single units
In sugars the
monomers are
monosaccharides
In lipids,none*
In proteins, amino acids
In nucleic acids,
nucleotides
Polymers
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Many monomers put
together
In sugars the polymers
are polysaccharides
In lipids, lipids
In proteins, proteins
In nucleic acids, nucleic
acids (DNA or RNA or
ATP)
Building Up & Breaking Down
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Anabolic Reaction called Dehydration
Synthesis (means “lose water to make”)
makes polymers from monomers.
Catabolic Reaction called Hydrolysis
(means water destruction) makes
monomers from polymers.
Examples
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Monosaccharide + monosaccharide is
made into a disaccharide and a
molecule of water is made in the
process. (see text picture)
Disaccharide is broken using a water
molecule into monosaccharide
+monosaccharide
Dehydration
Synthesis
Hydrolysis
Carbohydrates
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Sugars and starches are important fuel
sources for the human body as well as
making up structures in the body like cell
membranes.
Sugars are grouped by how many carbon
atoms they have and their names end in -ose.
A triose sugar has 3 carbons, etc.
Glucose is the main sugar that powers cells
like those in your brain.
Carbohydrates are the primary source of fuel
for your body. Any that are not used are then
converted to amino acids, fatty acids, etc.
Functions of Polysaccharides
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Polysaccharides are polymers of sugars.
Composed of hundreds of monosaccharides
joined by glycosidic linkages.
Storage polysaccharides include:
starch stored as granules in plastids of
plants
glycogen stored by animals in liver and
muscle cells
Polysaccharide Functions cont.
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Structural polysaccharides include:
cellulose in which the beta configuration
of glucose forms a strong fiber that is used all
over the world. (wood, rope, etc.)It also aids
the digestive systems of animals.
chitin is a carbohydrate used by insects
and related animals as an exoskeleton. It is
also used as building material for the cell
walls of fungi.
Lipids
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Consist mainly of hydrocarbons
Have little or no affinity for water
Store large amounts of energy
* do not really have monomers
although some will say their monomers
are fatty acids
Large molecules
How a Lipid is Constructed
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Formed from smaller molecules by
dehydration synthesis
Usually composed of fatty acids and a
glycerol (see diagrams)
Glycerol is an alcohol with 3 carbons-each
having a hydroxyl group (OH)
Fatty acid is a long hydrocarbon chain with a
carboxyl group
They vary in length and position of double
bonds.(saturated fats= more hydrogen)
Lipid Behavior
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Lipids are soluble in NONPOLAR
solvents and insoluble in polar solvents
(water).
Hydrophobic parts of lipid molecules
cause characteristic formations like
micelles and cell membranes to form.
Heads have an affinity for water and
tails are hydrophobic.
Lipid Functions
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Lipids function as insulators and energy
storage in the bodies of animals.
Structurally they form cell membranes
(phospholipid bilayer)
Proteins
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Composed of monomers called amino acids
(or peptides)
Diverse in structure and function (see chart in
text)
Exhibit simple to complex structures that
allow various functions (Primary to
Quaternary)
Folding of proteins is intensely studied
because the genetic code makes proteins.
The more we know about proteins, the more
we will know about our genetic code.
Amino Acids
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Amino acids are composed of:
Amino group
Carboxyl group
Hydrogen atom ( and asymmetric
carbon)
Variable group (R group) which varies
with the amino acid and determines the
unique characteristics of each amino acid.
They are linked by a covalent peptide bond.
Essential amino acids are those that cannot
by synthesized by the body.
Protein Structure
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Primary structure is a chain-the amino acid
sequence of a polypeptide.
Secondary structure is the shape in a
localized region of a polypeptide molecule.
Tertiary structure is the overall conformation
or shape of a polypeptide molecule.
Quaternary structure refers to the spatial or
conformational relationship between two or
more polypeptide molecules that make up a
protein.
Nucleic Acids
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Composed of nucleotides which themselves
are composed of:
pentose sugar
nitrogen base
phosphate group
Pentose sugar can either be ribose or
deoxyribose.
Nitrogen bases can occur as single rings
(pyrimidines) or double rings (purines)
Nucleic Acid Functions
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Nucleic acids function as information
storage(DNA and RNA) and energy transfer
compounds(ATP).
Information storage is in the sequence of the
nitrogen bases on the DNA molecule.
ATP is an adenine nucleotide with 2 additional
phosphate groups attached. It is the breaking
of the bonds that creates energy used in the
cell.