What Are Lipids?

What are lipids?

Lipids re molecules that are insoluble in polar solvents, such as water. Therefore, they are hydrophobic and nonpolar.

Lipids broken down into three major groups:

• Triglycerides
• Triglycerides consist of three fatty acids that are attached to a glycerol molecule
• Saturated:
• Has single covalent bonds only 
• Monounsaturated:
• Has one double covalent bond
• Polyunsaturated:
• Contains two or more double covalent bonds
• Examples: fats, oils or waxes
• Phospholipids
• A lipid that has one of the fatty acid chains replaced by a phosphate group
• They are amphipathic
• Has both nonpolar and polar regions
• The two fatty acid tails are hydrophobic
• Phosphate group (head) is hydrophilic
• Micelles have the phosphate group head pointing outward, while the fatty acid tails are covered inside
• They are important for the structure of the cell membranes
• Steroids
• Steroids are lipids that have a backbone of four linked carbon-rings
• Example:
• Cholesterol
• Testosterone and estrogen hormones

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