Macromolecules

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Chapter 05

• Macromolecules

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How Macromolecules are Made

• Main Macromolecules
• Carbohydrates
• Proteins
• Nucleic Acids
• All chainlike molecules called polymers
• Lipids
• Polymers long molecule consisting of many
  similar building blocks
• Monomers make up polymers

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Making Macromolecules

• Dehydration synthesis removing water from two
  monomers to make them form a chain
• Hydrolysis adding water to break the chain

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Dehydration Synthesis and Hydrolysis
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Carbohydrates

• Include sugars and their polymers
• Monosaccharides single monomer of sugar
• Disaccharides two monomers of sugar linked
  together
• Polysaccharides multiple monomers of sugars
  linked together

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Carbohydrates

• Can form rings or are linear
• Normally have a CH2O ratio
• Glucose is C6H12O6
• Position of H and O make differences in chemical
  behavior

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Disaccharides

• Consists of two monosaccharides joined together
  through a glycosidic linkage

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Dissacharide Linkage
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Polysaccharides

• Carbohydrates are the source of energy for most
  cells
• These energy carriers are stored in
  polysaccharides
• Starch plants
• Glycogen animals

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Structural Polysaccharides

• Organisms build strong materials from sugars
• Cellulose major component of plant cell walls
• Plants make 100 billion tons a year
• Made of glucose molecules
• Humans cannot digest cellulose due to ring
  arrangement

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Starch vs .Cellulose
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Structural Polysaccharides

• Chitin forms exoskeletons of insects

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Lipids

• Not made of polymers they are formed due to
  little or no affinity for water
• Hydrophobic
• Include waxes, oils, fats, phospholipids, steroids

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Lipids

• Store large amounts of energy
• Form long chains through dehydration synthesis
• Two parts of a lipid
• Glycerol backbone
• Fatty acids

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Saturated and Unsaturated Fats

• Fatty acids vary in length and number of and
  location of double bonds
• Saturated no double bonds in fatty acids
• Means that the carbon atoms are saturated with
  hydrogen
• Unsaturated double bonds exist
• Double bonds cause kinks in the fatty acid tails

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Saturated and Unsaturated Fats
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Phospholipids

• Two fatty acid tails (not three)
• Third hydroxyl group of the glycerol is joined to
  a phosphate group

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Phospholipids

• Phosphate head is hydrophilic
• Water loving
• Fatty acid tails are hydrophobic
• Water fearing
• Make up cell membranes
• Form a bi-layer to protect the cell

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Proteins

• Very important macromolecule
• Work horses of the cell
• DNA codes for building proteins
• Constructed of amino acids
• Chains of amino acids make a protein
• 20 amino acids
• Proteins are often referred to as polypeptides

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Protein Functions
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Amino Acids

• Made of Carbon, Carboxyl, Amino group, and
  R-group
• R-group makes different amino acids different
• Different amino acids have different properties
• Hydrophilic
• Hydrophobic
• Electrically charged

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Peptide Bonds

• How are amino acids linked to form proteins
• Peptide bonds
• When two amino acids are positioned so that the
  carboxyl group of one is close to the amino group
  of the other, and enzyme causes a dehydration
  reaction to occur.

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Protein Function

• Function relates to shape
• Proteins fold upon themselves
• The amino acid sequence determines what shape the
  protein will take

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Four Levels of Protein Structure

• Primary structure the unique sequence of amino
  acids
• Even slight changes in amino acid sequence
  changes the proteins function

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Four Levels of Protein Structure

• Secondary repeated coils or folds that
  contribute to proteins overall shape
• Attractions among the backbone form the secondary
  structure
• Alpha helix coil held by hydrogen bonds
• Beta pleated sheet held by hydrogen bonds

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Secondary Structure
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Four Levels Of Protein Structure

• Tertiary folding due to side chains

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Four Levels of Protein Structure

• Quaternary two or more proteins acting as a
  single unit

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Nucleic Acids

• Nucleic acids determine the primary sequence of
  proteins
• Genes made up of DNA
• Two types of nucleic acids
• Deoxyribonucleic acid DNA
• Ribonucleic acid RNA
• DNA to RNA to protein

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Nucleic Acids

• Nucleic acids are polymers of monomer called
  nucleotides
• Nucleotide anatomy
• Nitrogenous base
• Five carbon sugar
• Phosphate group

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RNA and DNA

• RNA contains four nucleotides
• Cytosine, Guanine, Uracil, Adenine
• Consists of one polynucleotide chain
• DNA contains four nucleotides
• Cytosine, Guanine, Thymine, Adenine
• Consists of two polynucleotide chains arranged in
  a double helix

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