5.3 Summary

5.3: Lipids include fats and steroids
*Key terms
-lipids: the compounds that water avoid to be mixed together
-hydrophobic: Water-avoiding molecules

-fat: organic compound consisting of a three-carbon backbone (glycerol) attached to three fatty acids.

-saturated fat: a fat in which all three fatty acid chains contain the maximum possible number of hydrogen atoms

-unsaturated fat: a fat that contains less than the maximum number of hydrogen atoms in one or more of its fatty acid chains.

-steroid: a lipid molecule in which the carbon skeleton forms four fused rings

-cholesterol: an essential molecue found in the membranes that surround our cells.

*Characteristics of Lipids

lipids= water-avoiding compounds ex) fat, oil

hydrophobic= water-avoiding molecules

-other types of lipids 1)stored as fats

2)circulate in our body as chemical signals to cells

*Fats

-three-carbon backbone(glycerol) with three fatty acids

-fats have solid and liquid

-tissues cushion your organs and provide body insulation

-saturated contains maximum possible hydrogen atoms bonded with carbons

ex) butter and animal fats

-unsaturated is less than the maximum # hydrogen atoms cuz of double bonds with carbons

ex) fruiths, vegetables, fish, corn oil, olive oil

*Steroid

- a lipid molecule in which the carbon skeleton forms four fused rings

- hydrophobic like lipids

- steroid estrogen and testosterone functions cause the appearance of male and female.

- the different structure of molecules of testosterone and estrogen

+ Cholesterol: an essential molecule found in the membrances that surround our cells. A tlpe of steroid

- high-level cholesterol increase risk for cardiovascular disease.

Concept Check 5.3

1. WHat property do lipids share?

- Lipids do not want to mix with water. Therefore, lipids act as a boundary that surrounds and contains watery cells.

2. WHat are the parts of a fat molecule?

- Fats consist of a three-caron backbone called glycerol attached to three fatty acids on each part. Fatty acids have long hydrocarbon chains.

3. Describe two ways that steroids differ from fats.

- Steroids differ in structure and function. Steroids circulate in our body as chemical signals. Their estrogen and testosterone cause male and female appearance. In structure, these two types of steroids differ in the location of molecules.

4. What does the term unsaturated fat on a food label mean?

- Unsaturated fat means that there are some double bonds on hydrocarbons.