Fatty Acids and Lipids Lecture Review

Final class and lecture of the course.
Discussion on impulse control in children.
Recommended dietary components include omega-3 and omega-6 fatty acids in appropriate ratios.

Excess fat tissue contributes to inflammation.
- Inflammation can stem from specific sterols in the body.
- Inappropriate ratio of fatty acids can lead to inflammation.
Inflammation is linked to:
- Joint pain.
- Cancer progression.
- Cancer cells utilize fatty acids advantageously to metastasize.

Saturated Fats:
- Examples include butter (a semisolid at room temperature) and solid fats like Crisco.
- Defined as having no double bonds between carbon atoms (alkanes).
- Structure characterized by all single bonds.
- This saturation means each carbon is bonded with the maximum number of hydrogen atoms.
- Key point: All carbons at bends and ends represent hydrogen atoms not drawn.
Unsaturated Fats:
- Includes fatty acids that contain one or more double bonds (alkenes).
- Monounsaturated Fat: One double bond.
- Polyunsaturated Fat (PUFA): More than one double bond.
- Also referred to as PUFAs; significant for identifying omega fatty acids.

Importance of distinguishing saturated and unsaturated fats:
- Bends in unsaturated fats prevent close packing, affecting their physical state (liquid vs. solid).
Formal relationships of hydrocarbons:
- Alkane: single bonds.
- Alkene: double bond.
- Alkyne: triple bond (not covered in detail).

Fatty acids are identified by carbon numbers which determine their structure.
Carbon skeleton representation in fatty acids:
- Carbon numbers indicated (e.g., C1 to C20).
- First number indicates total carbons, second total double bonds (e.g., for 20:5, five double bonds).
Omega classification:
- Omega-3 and omega-6 classification depends on the position of the first double bond relative to the end of the carbon chain.
- Example:
- Omega-3: First double bond at carbon-3.
- Omega-6: First double bond at carbon-6.

Recommended ratio of omega-3 to omega-6 intake:
- Ideal: 1:1 or 4:1.
- Typical American diet: 15:1 or worse.
Sources of omega-3:
- Examples: Flax seeds, salmon, avocados, and eggs.
Sources of omega-6 contribute more to inflammation:
- Examples: Vegetable oils (not olive oil), steak fat.
Inflammation impacts health, leading to:
- Joint pain and other complications (highlighting the importance of a balanced diet on health).

Triglycerides (or triacylglycerols):
- Simplest lipids, constructed from glycerol and three fatty acids.
- Variability in fatty acids attached (can be the same or different).
- Energy storage implications related to the number of double bonds and solubility:
- Fats with more double bonds are more soluble than those with fewer.
- This influences food state at room temperature (e.g., butter vs. olive oil).
Triglyceride structure discussed:
- Glycerol backbone with three attached fatty acids highlighted.

Description of the hydrogenation process:
- Used to improve shelf life, increases melting temperature of fats.
Partial hydrogenation leads to trans fats:
- Trans fats negatively affect cholesterol levels (raise bad cholesterol, lower good cholesterol).
- Government regulations aim to reduce trans fats in food.
Importance of being aware of trans fats in dietary intake.

Role of bile salts in fat digestion:
- Form emulsifications with fatty acids.
Enzyme lipase breaks down fats into smaller molecules, allowing transportation into the bloodstream.
Formation of monoglycerides and micelles through this process.

Comparison between cortisol and cholesterol:
- Both contain steroid structures and are involved in biological stress responses.
Mention of eicosanoids related to arachidonic acid and inflammation, with structural notes included for context.