pp. 157-163

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A carbon atom has 4 electrons available for bonding in its outer energy level.
To become stable, a carbon atom forms 4 covalent bonds that fills its outer energy level.
Carbon can bond with other carbon atoms.
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It can also bond with many other elements.
When carbon atoms bond to each other, they form:
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Straight chains
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Branched chains
Rings
These structures can have any number of C atoms and can also include atoms of other elements, i.e., H, O, N

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The ability to bond in so many ways makes it possible to have a huge number of carbon structures.

Molecular Chains
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Carbon compounds vary in size.
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Large organic molecules are called biomolecules ( macromolecules ).
Proteins are examples of macromolecules.
Polymers = a large molecule formed when many smaller molecules
( monomers ) bond together.

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Many polymers are formed by condensation reactions, a chemical reaction.
In condensation, the monomers that bond together to form polymers have an –H and an
–OH group that can be removed to form
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H-O-H, a water molecule (H
2
O)
Polymers can be broken apart in a chemical reaction called hydrolysis.
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Water is added in this process and the water causes the breakdown of the polymer.

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A carbohydrate is a biomolecule
(macromolecule) made of carbon, hydrogen, and oxygen.
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Ratio = C-H
2
-O
Simple carbohydrate = simple sugar called monosaccharide
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Glucose
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Fructose
These are isomeres.
Glucose + fructose = sucrose, a disaccharide.
 Sucrose = disaccharide (table sugar)
 Sucrose is created through a condensation reaction.

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Polysaccharides = largest carbohydrate molecules
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Polymers made of many monosaccharides
(monomers), which are linked together .
 Glycogen = linked glucose molecules
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 Animals store energy
Starch = linked glucose molecules
 Plants store energy
Cellulose = linked glucose molecules
 Plants use for structure
 Forms cell walls (structure unique to plants)

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Large biomolecules (macromolecules) made mostly of carbon and hydrogen with a small amount of oxygen.
Fats
Oils
Waxes
Steroids
All except steroids are made of fatty acids joined to glycerol.
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A fatty acid is a long chain of carbon and hydrogen atoms
Glycerol is an organic compound belonging to the alcohol family of organic compounds.

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Nonpolar
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They will not dissolve in water because they are nonpolar and are not attracted by water molecules.
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Remember that water is polar.

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Saturated fatty acids
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Each carbon in the carbon chain is singly bonded to the other carbons – all carbons are bonded with a single bond.
Unsaturated fatty acids
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Carbon atoms have double bonds with other carbon atoms, leave “empty” areas along carbon chain.
Fatty acids with more than one double bond are said to be polyunsaturated.
 Many double bonds…

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Energy storage
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Insulation
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Protective coverings
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Phospholipids
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Cell membrane

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Essential to all life
Large complex polymer
Building blocks (monomers) are amino acids
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20 amino acids
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Make 1000s of proteins
Carbon, hydrogen, oxygen, and nitrogen
Structure for tissues and organs
Cell metabolism

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Amino acids are linked together in condensation reactions.
Form a special covalent bond called a peptide bond
Proteins come in a variety of shapes and sizes.
The shape of the protein determines its function (what job it does).

Important because…
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Muscle tissue contraction
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Transportation of O
2 bloodstream in the
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Providing immunity
Regulating other proteins
Chemical reactions – enzymes speed up chemical reactions (p. 162)

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Complex biomolecule (macromolecule) that stores cellular information
Polymer made of monomers called nucleotides
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Nucleotides are made of :
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Carbon, hydrogen, oxygen, nitrogen and phosphorus atoms arranged in 3 groups:
Nitrogenous base
Simple sugar (deoxyribose or ribose)
Phosphate group

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Deoxyribonucleic Acid
Master copy of an organism’s information (genetic) code
Instructions to form enzymes and structural proteins
Determines how an organism will look and act
This genetic code is passed on from parent to offspring.

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Ribonucleic Acid
Forms a copy of DNA
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This copy is used for making proteins.
The chemical differences between RNA and DNA are minor but important.
DNA and RNA work together to make proteins.