Macromolecules

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Macromolecules

• Large Molecules
• Macromolecules are formed when monomers are
  linked together to form longer chains called
  polymers.
• The same process of making and breaking polymers
  is found in all living organisms.

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Condensation Reaction

• Consider some generic monomers with OH groups on
  their ends.
• These monomers can be linked together by a
  process called dehydration synthesis (also called
  a condensation reaction) in which a covalent bond
  is formed between the two monomers while a water
  molecule is also formed from the OH groups.
• This reaction is catalyzed by a polymerase
  enzyme.
• This same type of condensation reaction can occur
  to form many kinds of polymers, from proteins to
  carbohydrates, nucleic acids to triglycerides.

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Hydrolysis Reactions

• Polymers of all sorts can be broken apart by
  hydrolysis reactions. In hydrolysis the addition
  of a water molecule (with the help of a hydrolase
  enzyme) breaks the covalent bond holding the
  monomers together.

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Four major types of Macromolecules

• Lipids
• Carbohydrates
• Nucleic Acids
• Proteins

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Four major types of Macromolecules

• Diverse groups of molecules in nonpolymorphic form

• Lipids
• Carbohydrates
• Nucleic Acids
• Proteins

• Sugars

• Nucleotides

• Amino Acids

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Proteins

• Proteins consist of one or more polymers called
  polypeptides, which are made by linking amino
  acids together with peptide linkages.
• Peptide linkages are formed through condensation
  reactions.
• All proteins are made from the same 20 amino
  acids.
• Different amino acids have different chemical
  properties.

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Proteins

• Proteins primary structure largely determines
  its secondary, tertiary (and quaternary)
  structure.
• Proteins subjected to extreme conditions (large
  changes in pH, high temperatures, etc.) often
  denature.
• Proteins act as enzymes, and catalyze very
  specific chemical reactions.

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Proteins
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Carbohydrates

• Carbohydrates are always composed of carbon,
  hydrogen and oxygen molecules
• Monosaccharides typically have five or six carbon
  atoms.
• Monosaccharides can, such as the ribose and
  deoxyribose of RNA and DNA, can serve very
  important functions in cells.

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Carbohydrates

• Condensation reactions form covalent bonds
  between monosaccharides, called glycosidic
  linkages.
• Monosaccharides are the monomers for the larger
  polysaccharides.
• Polysaccharides play various roles, from energy
  storage (starch, glycogen) to structure
  (cellulose).

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Nucleic Acid

• Two types of nucleic acids
• DNA
• RNA
• DNA stores the genetic information of organisms
  RNA is used to transfer that information into the
  amino acid sequences of proteins.
• DNA and RNA are polymers composed of subunits
  called nucleotides.
• Nucleotides consist of a five-carbon sugar, a
  phosphate group and a nitrogenous base.
• Five nitrogenous bases found in nucleotides
• the purines
• adenine (A)
• guanine (G)
• the pyrimidines
• cytosine (C)
• thymine (T) (DNA only)
• uracil (U) (RNA only)

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Nucleic Acid

• DNA is transmitted from generation to generation
  with high fidelity, and therefore represents a
  partial picture of the history of life.

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Nucleic Acid
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Lipids

• Lipids constitute a very diverse group of
  molecules that all share the property of being
  hydrophobic.
• Fats and oils are lipids generally associated
  with energy storage.
• Fatty acids, which make up fats and oils, can be
  saturated or unsaturated, depending on the
  absence or presence of double bonded carbon
  atoms.
• Other types of lipids are used for a other
  purposes, including pigmentation (chlorophyll,
  carotenoids), repelling water (cutin, suberin,
  waxes) and signaling (cholesterol and its
  derivatives).

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Lipids

• Lipids are joined together by ester linkages.
• Triglyceride is composed of 3 fatty acid and 1
  glycerol molecule
• Fatty acids attach to Glycerol by covalent ester
  bond
• Long hydrocarbon chain of each fatty acid makes
  the triglyceride molecule nonpolar and hydrophobic

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Lipids
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