Macromolecules

1
Macromolecules

• Building Complex Molecules That Comprise Living
  Things

2
Macromolecules Polymers Made of Repeating
Monomers
Macromolecule Monomer Unit
Carbohydrates Sugars
Lipids Fatty acids
Proteins Amino acids
Nucleic Acids Nucleotides
3
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

• Complex
• Polysaccharides many sugar units

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Chemically- Modified Carbohydrates
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Carbohydrates Functions

• Energy source
• Source of carbon skeletons for synthesis of other
  biological molecules
• Structural component of cells
• Cell-cell communication

8
Eating Any Carbs Lately?
How can I use this info?

• Nutritionists recommend that carbohydrates be
  included as an important energy source in the
  diet
• Emphasize
• Complex Carbohydrates
• Starch
• Fiber (cellulose)
• Naturally-occurring simple carbohydrates
• Fructose from fruit
• Lactose from milk

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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
• Used to produce
• Hormones
• Cholesterol
• Vitamin D2

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Lipids Functions

• Concentrated energy source
• Structural components of cell membranes
• Phospholipids
• Cholesterol
• Carotenoids capture light energy for
  photosynthesis
• Communication
• Steroid Hormones
• Metabolism
• Fat-soluble vitamins
• Insulation
• Protection from water
• Waxes

Cholesterol
Phospholipids
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High Fat, Low Fat, No Fat
How can I use this info?

• Limit fats to lt 30 of calories
• Limit saturated fats to lt 10 of calories
• 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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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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Proteins Structure Forming the Protein Chain
Phenylalanine
Leucine
Dehydration Synthesis between COOH NH2
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Proteins Structure Forming the Protein Chain
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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Protein Folding Within the Cell

• Proteins called chaperonins assist in proper
  folding of newly synthesized proteins
• Some chaperonins trap proteins in a molecular
  cage to prevent interference in the folding
  process

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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

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Interactions in Tertiary Structure
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Maintaining Protein Structure

• Denaturation disrupts tertiary and secondary
  structure and is not usually reversible
• Denaturation can be caused by heat, pH changes
  and other chemicals such as salts or charged ions

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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
• Transport
• Protection and Support
• Movement
• Growth and Repair
• Defense Against Disease
• Communication/Regulation
• Protein Hormones
• Cell Receptors
• Energy source

Protein
Protein
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For the Remaining Calories
How can I use this info?

• Protein requirements are based on body size and
  needs for growth
• 8 essential amino acids obtained from
• Lean sources of animal protein
• Complementary plant proteins
• Beans Grains
• Beans Seeds