Lipids Flashcards
What are Lipids
Lipids are a wide variety of compounds, more frequently known by their common names, including fats, oils, waxes.
are all insoluble in water.
Composed of C, H, O
What are the functino of Lipids
-Long-Term Energy storage: fat is excellent for storing energy in the least amount of space, and packs 9.1 calories of energy per gram, versus 4.4 for carbohydrates and proteins.
-Insulation (“blubber”)
-Padding of vital organs
- Cell Membrane Structure
- hemical messengers (e.g. steroid hormones like testosterone, estrogen, prostaglandins). Made from Cholesterol
What are the main types of Lipids
Fatty Acids, Neutral Fats, Phospholipids, Steroids
What are Fatty acids
a long chain of carbons with hydrogens attached ending in an acid group (-COOH)
What are the two main types of Fatty Acids
Saturated - all carboins are saturated with hydrogens. Solid at room temperature, Most animal fats, No C-C double bonds
Unsaturated - have one or more double bonds between carbons in chain, carbons are not saturated with hydrogens. Liquid at room temp.
Plant & fish fats
What are neutral fats
also called TRIGLYCERIDES)
Triglycerides store unused calories and provide your body with energy.
formed by dehydration synthesis reaction between glycerol (a molecule of 3 hydrated carbons) and 3 fatty acids.
fatty acids in a neutral fat can be saturated or unsaturated
All triglycerides are non-charged, non-polar molecules.
They do not mix with water. This property of not mixing with water is called “hydrophobic” which literally means “water-fearing.”
This is the opposite of polar molecules, which mix readily with water and are called “hydrophilic” which means “water-loving.”
How is soap made
Soap is made by combining a base and a fatty acid.
Soaps are polar, will mix with water. Soap molecules surround oil droplets so their polar ends project outwards, causing the oil to disperse in water (this process called EMULSIFICATION).
what are phospholipids
PHOSPHOLIPIDS: important components of cell membranes
a barrier to protect the cell against various environmental insults and more importantly, enables multiple cellular processes to occur in subcellular compartments.
Phospolipids have the same basic structure as neutral fats except that one fatty acid is replaced by a phosphate group with a charged nitrogen attached.
phospholipids have a Phosphate-containing “head” and two long fatty acid tails. Head is hydrophilic (“water-loving”), tail is hydrophobic (“water-fearing”)
What are steroids
a different type of lipid
They are multi-ringed structures, all derived from CHOLESTEROL
You’ve heard many bad things about cholesterol, but it is actually an essential molecule found in every cell in your body (it forms parts of cell membranes, for example).
The problem is that dietary cholesterol helps to form arterial plaques, which lead to strokes and heart attacks.
Steroids can function as chemical messengers, and form many important HORMONES (e.g. testosterone, estrogen, aldosterone, cortisol) that have a wide variety of affects on cells, tissues, and organs (especially sex characteristics, ion balance, and gluconeogenesis).
