Chapter 5 Section 3 Lipids

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Chapter 5 Section 3Lipids

• Mrs. Kerstetter
• Biology

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Lipids

• Lipids
• Lipids are generally not soluble in water.
• Which means they are HYDROPHOBIC
• Lipids are made mostly from carbon and hydrogen
  atoms.

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Lipid structure
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Lipids

• The common categories of lipids are
• fats
• oils
• waxes
• steroids

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Lipids

• What is the function of lipids?

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Lipids

• Lipids can be used to store energy.
• Some lipids are important parts of biological
  membranes and waterproof coverings. In other
  wordsBOUNDARIES
• Some circulate in the body as chemical signals
  to other cells

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Lipids

• Many lipids are formed when a glycerol molecule
  combines with compounds called fatty acids.
• If each carbon atom in a lipids fatty acid
  chains is joined to another carbon atom by a
  single bond, the lipid is said to be SATURATED.
• The term saturated is used because the fatty
  acids contain the maximum possible number of
  hydrogen atoms.

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Lipids

• If there is at least one carbon-carbon double
  bond in a fatty acid, it is UNSATURATED.
• Lipids whose fatty acids contain more than one
  double bond are polyunsaturated.
• Lipids that contain unsaturated fatty acids tend
  to be liquid at room temperature.
• Saturated fats are SOLIDS at room temperature.

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Steroids

• a lipid molecule in which the C skeleton forms
  4 fused rings
• -all steroids have a core set of 4 fused rings,
  but they are different in the kinds and locations
  of functional groups attached to the rings

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Steroids

• Classified as lipids because they are hydrophobic
• Functions
• Circulate in body as chemical signals
• Starting point for other steroids
• Estrogen and testosterone are sex hormones cause
  major differences in female and male sexual
  characteristics

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Steroids
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Cholesterol

• Best known steroid
• Found in molecules that surround your cells
• Starting point for making other hormones
• Bad RepWhy?
• High levels of LDL and VLDL are linked to
  increase risk of cardiovascular disease