LIPIDS &
                 I. LIPIDS:
§ Commonly called fats & oils
§ Contain more C-H bonds and less O
  atoms than carbohydrates.
  l   Ex: C57H110O6

§ Nonpolar; therefore repel water
              I. LIPIDS:
§ Functions of lipids in our body:
  1. Long term energy storage (used when
     carbohydrates are NOT available)
  2. Insulation
  3. Protect body tissue (cushioning)
§ One gram of fat contains
  TWICE as much energy as one
  gram of carbohydrates.
  Therefore, fats are better
  storage compounds!
Types and Examples of Lipids:
1. Sterols- steroids
2. Waxes – bee, furniture, ear, car
3. Cholesterol- in egg yolks, red meat
4. Fats- from animals
5. Oils – from plants
       Structure of Lipids:

§ Basic building blocks:
           3 fatty acids + 1 glycerol
§ Fatty Acids
  l   Long chains of carbon with a carboxyl
      group at one end
     Structure of Lipids:
§ One fatty acid:
       Structure of Lipids:

§ Glycerol and
  each fatty acid
  chain are joined
  to each other by
    Structure of a lipid
(1 glycerol + 3 fatty acids):
            3 types of fats:
1. Saturated fats = fatty acid chains of
  carbon with only single bonds between
  the carbon atoms
  l   Solid at room temperature
      • Ex: butter
           3 types of fats:
2. Unsaturated fats = fatty acid chains of
  carbon with ONE double bond between
  the carbon atoms
  l   Liquid at room temperature
      • Ex: Olive oil
         3 types of fats:
3. Polyunsaturated fats = more than one
  double bond between the carbon atoms
  in the chain
Structural formulas for saturated and
    polyunsaturated fatty acids:

Polyunsaturated Fatty Acid
What happens to LIPIDS in
       the body?
§ Broken down by the digestive system
  into fatty acids and glycerol which are
  then absorbed into the body through the
  bloodstream, where the body cells take
  the fatty acids and glycerol and make
  needed lipids
               I. Lipids:
§ Triglycerides = Majority of fat in
  organism consist of this type of fat
  l   Derived from fats eaten in foods or
      made in the body from other energy
      sources like carbohydrates.
             I. Lipids:
Calories ingested in a meal and not used
immediately by tissues are converted to
triglycerides and transported to fat cells
to be stored.
  Storage – 3 month supply of energy
  vs. glycogen’s 24 hour supply
            I. Lipids:
Hormones regulate the release of
triglycerides from fat tissue so they
meet the body's needs for energy
between meals.
Excess Triglycerides- Life Applications:
Cause plaque to build up
  Arteriosclerosis =
  walls of the arteries
  get thick and hard;
  fat builds up inside
  the walls and slows
  the blood flow
   • Cause blood clots –
     heart attacks,
Excess Triglycerides- Life Applications:

 Hypertension (high blood pressure)
        II. PROTEINS:
Large complex polymer composed of C, H,
O, N, & sometimes S
Basic building blocks: Amino acids
  20 different amino acids
        II. PROTEINS:
Example amino acid:
        II. PROTEINS:
Amino acids are linked together by
dehydration synthesis to form a protein
                II. PROTEINS:
Ex: 2 amino acids joined by dehydration

         II. PROTEINS:
Peptide bond = a covalent bond that
joins amino acids to each other
        II. PROTEINS:
Proteins- named for the number of amino
acids that make them
  otwo amino acids = dipeptide
  othree amino acids = tripeptide
  omany amino acids = polypeptides
       II. PROTEINS:
Essential Amino Acids:
 10 of the 20 amino acids are “essential”
 because they are required by the body
 but are NOT created by it.
  oAs a result, it must be provided by our
   diet. If one is missing then proper
   growth and repair cannot be
    Functions of proteins in our body:

1. Muscle contraction

2. Transport oxygen in
   the bloodstream
    Functions of proteins in our body:

3. Provide immunity
                             4. Carry out
What happens to PROTEINS in
         the body?
Broken down by the digestive system
into amino acids which are then
absorbed into the body through the
bloodstream, where the body cells take
the amino acids and makes protein for

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