Summary of Concept 5.3

Concept 5.3

Notes

• Oil is in the class of lipids, meaning it avoids water.
• Any molecule that avoids water is hydrophobic.
• Fat is a three carbon backbone with glycerol attached.
• Fats provide your body with insulation.
• Saturated fats have all three acids chains containing as many hydrogen atoms as possible.
• Unsaturated fats are not saturated with hydrogen atoms.
• Too much saturated fat is unhealthy.
• A lipids that have a carbon skeleton forming four fused rings are called steroids.
• Steroids all have different functions.
• Cholesterol is probably the most well known steroid. It is required in the cell membranes of the human body.

Concept Check

1. What properties do lipids share?
All lipids are hydrophobic, meaning they avoid water (like the plague).

2. What are the parts of a fat molecule?
Fat molecules are made of a three carbon skeleton, surrounded by glycerol, with three long chains of acidic hydrocarbon attached.

3. Describe two ways that steroids are different from fats.
Steroids are in a formation of a ring, not a chain, also, steroids have different functions from fats.

4. What does the term unsaturated fat on a food label mean?
When a food label has unsaturated fat written on it, it is generally better for one's body then saturated fat, which has as many hydrogen atoms as possible, as opposed to the unsaturation of hydrogen atoms in unsaturated fats.