Biochemistry- The Macromolecules

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Biochemistry- The Macromolecules

• Unit 3 The Chemical Building Blocks of Life
• Honors Biology
• Monkemeier
• 2011

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Four Main classes of organic compounds are
essential to the life processes of all living
things

• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids
• You will see that although these compounds are
  built primarily from carbon, hydrogen, and
  oxygen, these atoms occur in different ratios in
  each class of compound.

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Carbohydrates

• Carbohydrates are organic compounds composed of
  carbon, hydrogen, and oxygen in a ratio of about
  one carbon atom to two atoms of hydrogen atoms to
  one oxygen atom.
• 1C2H1O

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Functions of Carbohydrates

• Some carbohydrates serve as a source of energy.
• Other carbohydrates are used as structural
  materials.

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Carbohydrates

• A monomer of a carbohydrate is called a
  MONOSACCHARIDE.
• A MONOSACCHARIDE is also called a simple sugar.
• A monosaccharide contains carbon, hydrogen and
  oxygen in a ratio of 1C2H1O
• Simple sugars are used a a source of quick energy

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Most Common Monosaccharides

• Glucose the main source of energy for cells
• Fructose found in fruits and is the sweetest of
  the monosaccharides
• Galactose is found in milk

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Glucose
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Glucose, Galactose, Fructose
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Isomers

• Glucose, Galactose and Fructose have the same
  molecular formula, but different structural
  formulas.
• Glucose, Galactose and Fructose are all isomers.
• Isomers are compounds with the same chemical
  formula, but different structural forms.

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Disaccharides

• Two monosaccharides combine to form a
  disaccharide
• (Do you remember the name of the chemical
  reaction that builds polymers from monomers?)
• Answer
• Condensation or Dehydration Synthesis

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Disaccharides

• Di means two
• Three common Disaccharides are
• - Lactose (found in milk)
• - Maltose
• - Sucrose (table sugar)

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Lactose
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Maltose
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Polysaccharides

• Poly means many
• These are large sugars composed of more than
  three monosaccharides
• Glycogen
• Starch
• Chitin
• Cellulose

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Functions of the Polysaccharides

• Glycogen how animals store glucose
• Starch how plants store glucose
• Cellulose composes cell walls of plants
• Chitin the exoskeleton of arthropods

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Structure of Starch
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Structure of Cellulose
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Reminder Condensation Reaction (Builds Polymers)
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Hydrolysis or Decomposition

• Is the Chemical Reaction that breaks polymers
  into their monomers.
• Starch can be broken into its glucose units by
  using hydrolysis.

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Proteins

• Are organic molecules composed of mainly carbon,
  hydrogen, oxygen and nitrogen.
• Like most other biological macromolecules,
  proteins are formed from the linkage of monomers
  called amino acids
• There are 20 different amino acids

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Amino Acids

• All 20 amino acids share the same basic structure
• Every amino acid contains
• - an amino group
• - a carboxyl group
• - a hydrogen atom
• - a central carbon atom

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Amino Acid Structure
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Amino Acid Structure
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R Groups

• The main difference among the 20 amino acids is
  in their R groups.
• The R group can be simple or complex
• The differences among the amino acid R groups
  gives proteins very different shapes.

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DIPEPTIDE

• Two amino acids are put together to form a
  dipeptide.
• The bond between the amino acids is called a
  PEPTIDE BOND

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Polypeptide

• A long chain of amino acids put together with
  peptide bonds is called a POLYPEPTIDE.
• Proteins are composed of one or more polypeptides.

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Enzymes

• Many enzymes are proteins.
• Enzymes can be made from RNA too!
• Enzymes are organic catalysts
• Enzymes lower the activation energy of chemical
  reactions
• Enzymes increase the rate of chemical reactions.

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Enzyme reactions depend on a physical fit between
the enzyme molecule and its specific substrate.
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Substrate the reactant being catalyzed
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Active Site area on enzyme that fits the shape
of the substrate
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Changes in the environment

• Can affect enzymes
• Such as change in temperature
• Such as change in pH
• May change the shape of the enzyme so that it
  will no longer fit the substrate.

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Lipids aka FATS

• Lipids are large, nonpolar organic molecules.
• LIPIDS do NOT Dissolve in Water!
• Lipids have a higher ratio of carbon and hydrogen
  atoms to oxygen atoms than carbohydrates have.
• Lipids store more energy per gram than other
  organic compounds due to the carbon-hydrogen
  bonds.

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Five Categories of Lipids

• Fatty Acids
• Triglycerides
• Phospholipids
• Waxes and Oils
• Steroids

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Fatty Acids

• Fatty Acids are unbranched carbon chains that
  make up most lipids
• On one end of the carbon chain is a carboxyl
  group.
• On the other end of the carbon chain is a methyl
  group

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Fatty Acids
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The ends of the fatty acid chain have different
properties

• The carboxyl end is polar and is hydrophilic
• The carboxyl end will dissolve in water.
• The methyl end is nonpolar and is hydrophobic.
• The methyl end will not dissolve in water.

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Saturated and Unsaturated Fatty Acids

• If the carbon chain contains double bonds, it is
  considered unsaturated.
• If the carbon chain contains single bonds, it is
  considered saturated.

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Triglycerides

• Triglycerides are composed of a molecule of
  glycerol and three fatty acid chains.
• Saturated triglycerides contain fatty acids that
  have single bonds.
• Saturated triglycerides include butter, fats and
  red meat.
• Unsaturated triglycerides contain fatty acids
  that have double bonds and are found in plant
  seeds.

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Triglycerides
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Phospholipids

• Phospholipids have two fatty acids attached to a
  molecule of glycerol.
• Compose cell membranes
• Have a phosphate group attached to the molecule
  of glycerol.

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Phospholipids
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Phospholipids
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Phospholipids and Cell Membranes
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Waxes

• A wax is a type of structural lipid consisting of
  a long fatty-acid chain joined to a long alcohol
  chain.

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Waxes

• Waxes are waterproof, and in plants, form a
  protective coating on the outer surfaces.
• Waxes also form a protective layer in animals.

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Steroids

• Steroid molecules are composed of four fused
  carbon rings.
• Many animal hormones are steroid compounds
• Cholesterol and testosterone are steroids.

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Steroids
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Nucleic Acids

• Nucleic acids are very large and complex organic
  molecules that store and transfer important
  information in the cell.
• There are two main types of nucleic acids DNA
  and RNA.
• DNA deoxyribonucleic acid
• RNA Ribonucleic acid

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Nucleotides

• The monomers of nucleic acids are nucleotides.
• There are three components to a nucleotide
• - nitrogen base
• - sugar
• - phosphate

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Nucleotides
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Nucleotides
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DNA

• Is a double helix
• Is found in the nucleus
• Stores hereditary information

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RNA

• Is a single helix
• Can be found in the nucleus and the cytoplasm of
  the cell
• Helps build proteins
• Can act as an enzyme

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Compare DNA to RNA

• DNA
• Found in nucleus
• Stores hereditary information
• Has deoxyribose as the sugar
• Is a double helix

• RNA
• Found in nucleus and cytoplasm
• Helps build proteins
• Has ribose as the sugar
• Is a single helix

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What are the monomers of each of the following
polymers?

• Carbohydrates
• Proteins
• Lipids
• Nucleic Acids

• Monosaccharides
• Amino acids
• Fatty acids and glycerol
• nucleotides

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The End