Macromolecules

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Macromolecules

• Building Complex Molecules That Comprise Living
  Things

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Comparison of Terms
Molecule Two or more atoms joined by chemical bonds
Macromolecule Large polymer made of repeating monomer units
Four types of organic macromolecules are
important in living systems.
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Macromolecules Polymers Made of Repeating
Monomers
Macromolecule Monomer Unit
Carbohydrates Sugars
Lipids Fatty acids
Proteins Amino acids
Nucleic Acids Nucleotides
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Organic Macromolecules Contain Carbon

• Question How many electrons does carbon
  need to fill its outer energy level?

• Answer Four

Each carbon atom can make four covalent bonds
with other types of atoms or additional carbons.

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Synthesis and Breakdown of Macromolecules
Dehydration Synthesis Removal of water to add monomer units
Hydrolysis Addition of OH and H groups of water to break a bond between monomers
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Dehydration Synthesis / Hydrolysis
Dehydration Synthesis
Hydrolysis
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Carbohydrates Structure

• Simple
• Monosaccharides one sugar unit

Glucose blood sugar All cells use glucose for
energy
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Carbohydrates Structure

• Simple
• Disaccharides two sugar units

Sucrose Water
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Carbohydrates Structure

• Simple
• Disaccharides two sugar units
• Sucrose glucose fructose table sugar
• Lactose glucose galactose milk sugar
• Maltose glucose glucose seed sugar

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Carbohydrates Structure

• Complex
• Polysaccharides many sugar units
• Starch -- storage in plants
• Glycogen -- storage in animals
• Cellulose -- plant cell walls, indigestible
• Chitin -- exoskeletons of insects,
  fungal cell walls

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Chitin
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Carbohydrates Functions

• Energy source
• Structural component
• Cell-cell communication

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Carbohydrates Dietary Recommendations

• 58 of calories from carbohydrates
• No more than 10 of calories from simple, refined
  sugars
• Emphasize
• Complex Carbohydrates
• Starch
• Fiber (cellulose)
• Naturally-occurring simple carbohydrates
• Fructose from fruit
• Lactose from milk

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Macronutrients As Energy Sources
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Applying Your Knowledge

1. Monosaccharide
2. Polysaccharide
3. Disacharide

1. Which molecule consists of two sugar units?
2. Which choice best describes glycogen?
3. Which type of molecule provides the basic energy
   for your cells?
4. Which type of molecule is found in milk?

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Macromolecules Polymers Made of Repeating
Monomers
Macromolecule Monomer Unit
Lipids (fats, oils, waxes) Fatty acids
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Lipids Structure

• Triglyceridepredominant form in diet
• One molecule of glycerol
• Three fatty acids

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Lipids Structure

• Types of Fatty Acids
• Saturated 2H per internal carbon
• Unsaturated -- lt2H per internal carbon
  ?one or more double bonds
• Monounsaturated one double bond
• Polyunsaturated more than one double bond

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TriglycerideFormation
Triglyceride
Glycerol
RemoveTheseWaters
Add 3FattyAcids
3 Waters
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Which Is a Source of Unsaturated Fatty Acids?
Linseed Oil
Beef Fat
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Lipids Structure

• Phospholipidcomponent of cell membranes

PolarHead
Glycerol
Fatty Acid Tails
Hydrophobic
Hydrophilic
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Lipids Structure

• Steroids
• Linked carbon rings
• Natural body components
• Hormones
• Cholesterol

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Steroids
Cholesterol
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Lipids Functions

• Concentrated energy source
• Structural components of cell membranes
• Phospholipids
• Cholesterol
• Communication
• Steroid Hormones
• Protection from water
• Waxes

Cholesterol
Phospholipids
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Lipids Dietary Recommendations

• lt 30 of calories from lipids
• lt 10 of calories from saturated fats
• Limit cholesterol to 300 mg/day
• Avoid trans fatty acids in partially
  hydrogenated products
• Emphasize
• Unsaturated fatty acids from vegetables, fish,
  legumes, and nuts
• Oils mono- or polyunsaturated

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Macronutrients As Energy Sources
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Applying Your Knowledge

1. Polyunsaturated fatty acid
2. Cholesterol
3. Monounsaturated fatty acid
4. Saturated fatty acid

1. Which molecule is made of a series of carbon
   rings?
2. Which molecule has more than one double bond?
3. Which molecule has 2H for each internal carbon?
4. Which molecule has one double bond?

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Macromolecules Polymers Made of Repeating
Monomers
Macromolecule Monomer Unit
Protein Amino acids
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Proteins Structure

• Primary structure chain of amino acids
• Amino acids have common features

Carboxylic AcidGroup
AminoGroup    
R
AlphaCarbon
The R GroupDiffers for Each Amino Acid
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Amino Acids Phenylalanine Structure
PhenylalanineR Group
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Amino Acids Leucine Structure
Leucine R     Group
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Proteins Structure Forming the Protein Chain
Phenylalanine
Leucine
Dehydration Synthesis between COOH NH2
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Proteins Structure Forming the Protein Chain
The Peptide Bond
Water
Phenylalanine-Leucine Dipeptide
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Four Levels of Protein Structure
Tertiary(Folding by R-group interactions)
Primary(Sequence)
Quaternary(Two or more chains associating)
Secondary(Coiling by Hydrogen Bonding)
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Four Levels of Protein Structure
Primary Structure sequence of amino acids in
chain
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Four Levels of Protein Structure

• Secondary Structure
• Folded structure due to hydrogen bonds between
  the amino and acid groups of amino acids

C
N
C
N
H
O
H
O
or
O
H
O
H
N
C
N
C
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Found in most proteins
Found in silk
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Four Levels of Protein Structure

• Tertiary Structure
• Three dimensional folded structure due to
  attractions and repulsions between R groups
• Can involve
• covalent bonding hydrogen bonding ionic
  interactions hydrophilic and hydrophobic
  interactions

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Hair Curling
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Four Levels of Protein Structure

• Quaternary Structure
• Association of two or more protein chains

eg. Hemoglobin is composed of 4 protein
chains 2 are called alpha
hemoglobin 2 are called beta
hemoglobin
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Proteins Functions

• Structural Component of Cells
• Control of Metabolic Reactions enzymes
• Growth and Repair
• Communication
• Protein Hormones
• Cell Receptors
• Energy source

Protein
Protein
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Proteins Dietary Recommendations

• 12 of calories from proteins
• 8 essential amino acids obtained from
• Lean sources of animal protein
• Complementary plant proteins
• Beans Grains
• Beans Seeds

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Applying Your Knowledge

1. Primary
2. Secondary
3. Tertiary
4. Quaternary

1. Which structure results from hydrogen bonding?
2. Which structure involves an association of two or
   more protein chains?
3. Which structure describes the linear sequence of
   amino acids?
4. Which structure depends upon interactions between
   the R groups of the amino acids?