Lipids

Explain why phospholipids are amphipathic molecules.

A phosphate containing compound REPLACES a fatty acid, giving it emphatic properties. The phosphate functional group has a negative electrical charge this portion is HYDROPHILIC. The two fatty acids are hydrophobic forming a bilayer to keep the fatty acids dry while the phosphate heads face outward, this forms membranes.

Correctly state the number of double bonds in a hydrocarbon chain based on the chemical formula (for example: how many double bonds are present in a molecule with the formula C₆H₁₀?)

Two double bonds are present.

Predict the effect on the physical state (solid versus liquid) of a triglyceride if double bonds are introduced or removed from the fatty acid side chains.

If more double bonds are introduced, the triglyceride will be unsaturated aka an oil. Because of kinky bonds.

Recognize an example of a triglyceride

3 fatty acid side chains are present

Explain what it means if a triglyceride is saturated or unsaturated.

- If a triglyceride is saturated it means that it's all single bonds. A saturated fatty acid is usually solid or semisolid at room temperature and are called "fats." - An unsaturated triglyceride has one or more double bonds making it "kinky" and unable to pack together tightly.

List the functions of the three different types of lipids.

1. Triacylglycerols (fats and oils) - Function: Energy storage. Fats are a more compact fuel than starch. 2. Phospholipids: lipid bilayers - Function: Due to this "amphipathic" nature (both water-loving and water-hating regions in a single molecule), phospholipids self assemble into bilayers that shield the tail from water = forming membranes (phospholipid bilayers!). 3. Steroids (cholesterol, steroid hormones): Functions of Cholesterol: (1) Help to maintain membrane fluidity, pliability (flexibility) and resilience in membranes of animals, which have high amounts or rigid, saturated fatty acids. (2) Sex hormones (testosterone, estrogen and progesterone) are all made from cholesterol Cholesterol gets a 'bad rap" in our diet, but has CRUCIAL roles in the functioning of our cells - we couldn't live without cholesterol!!!

Recognize examples of a steroid:

Are not polymers, are not modular • have a carbon skeleton of four interconnected rings. Cellular communication

Name the organelles of eukaryotic cells in which lipids are synthesized.

Lysosome, Nucleus, Nucleolus, Golgi Apparatus, Cell Membrane, Endoplasmic Reticulum (Smooth and Rough), Cell Wall (Plant Only), Chloroplasts (Plant Only), Mitochondria, Vacuole, and Cytoplasm (Gel Everything Else Is Suspended In).

Draw a triglyceride and a phospholipid. Label the glycerol, the fatty acid side chains, the ester bonds, and the polar head group of the phospholipid.

Modular.