Lipids Flashcards
What do lipids use to store energy?
Glucose converted to Glucose6P, goes through glycosis to produce pyruvate and then with PDH forms TCA, which then forms citrate and you have fatty acid synthesis.
What are the useful benefits of lipids?
Fats and oils for energy storage.
Insulation from environment- heat and shock absorber.
Water repellent,e.g. birds, sheep.
Prevents evaporation in plants.
How are lipids good biological membranes?
They are a barrier between cells and the environment. They are essential for generating electrochemical gradients.
Lipids are light absorbing _________.
pigments
Lipids are anchors for ________.
proteins
What additionally are lipids good for?
Vitamins
Hormone production
Give the 4 ways lipids are building blocks and a description?
Lipids- Chemically diverse
Oils- Viscous liquid immiscible in water.
Fats- Soft greasy substance, composed of lipid mixtures.
Wax- Harder and less greasy than fats. Form solids at ambient temperatures.
What is a fatty acid made up of?
Carboxyl group- Called the ‘head group’, anionic, POLAR.
Hydrocarbon chain- (4-36) carbons, almost always even, HYDROPHOBIC.
Are there many types of lipids?
100 fatty acids known- differ in chain length and saturation.
What is the difference between a saturated and unsaturated fatty acids?
In the hydrocarbon chain of the fatty acid in saturated fats all the bonds are C-C= saturation.
However in unsaturated fats the hydrocarbon chain has >1 C=C bonds= unsaturation.
Does the C=C bond rotate?
It does not rotate.
What does cis mean in relation to fatty acids.
An unsaturated fatty acid where the hydrogen atoms bonded to double-bonded carbon atoms are on the same side, resulting in a kinked shape of the carbon chain.
C=C in most natural fatty acids are ___
Cis
What is the nomenclature of fatty acids?
The last C in chain is always ⍵.
No C=C is saturated
≥C=C is unsaturated
1 C=C is monounsaturated
>1 C=C is polyunsaturated.
What is the omega nomeclature for polyunsaturated fatty acids?
Counting for C=C bond goes up from the omega carbon.
This is because they are important for human nutrition.
If there is a C=C at the 3rd C from the omega this becomes an omega 3 fatty acid.
If there is a C=C at the 6th C from the omega this becomes an omega 6 fatty acid.
What happens when chain length increases of the fatty acid?
Solubility decreases
Melting point increases.
What happens when the saturation level of a fatty acid increases?
the melting point decreases.
What type of C=C bonds do natural fats have?
Cis C=C bonds.
Describe the nature of trans C=C bonds?
Extended and increase melting point.
How do trans fats have increased shelf-life?
Fats are partially hydrogenated for C=C to C-C which stops the double bonds from oxidising.