Lipids

Defining the Lipid

A insoluble non-polar macromolecule produced by enzymes

Use cases for lipids

Long term energy storage
Phospholipid membrane formation
Hormone communication

Fatty Acids

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Fatty Acids (sry couldn't draw this one)

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Fats

glycerol + 3 fatty acids $\to$ triglyceride (fat)

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Triglyceride (Fat)
molecules become hydrophobic
(low solubility) - OH groups are
anabolized and the hydrocarbon
is non polar

Polar Hydroxyls

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Animal vs Plant Fats

Animal fats are typically saturated while plant fats are typically unsaturated

Phospholipids

glycerol + 2 fatty acid + phosphate group (polar) $\to$ phospholipids

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Phospholipids

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Properties

Phospholipids have a hydrophilic head, hydrophobic tail
- Because of this dual nature, it is said to be amphipathic
  - Think: - where have you heard this before?
The cell membrane is made of a bilayer of phospholipids
- This traps all fats inside, stuck between both heads
Sometimes the head can also feature other polar molecules, but phosphate groups are always present
Water can sometimes get through this highly hydrophobic layer, either through a small opening, or a hydrophilic pore created by a enzyme

Steroids

Typically found in a 4 ring structure (3 hexagonal rings, 1 Pentagon):