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18 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What are lipids? |
Fats, oils and cholestrol which act as a insoluble store of energy used to waterproof cells |
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What is made of lipids in animals? |
1. Cell membranes 2. Steroid hormones |
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What are the two functions of fat? |
1. Physically protects organs 2. Insulation |
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What are (most) lipids composed of? |
A glycerol molecule bonded to fatty acid molecules (not polymers) |
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What is the structure of a fatty acid? |
CH³(CH²)¹⁴COOH 1. CH³ is a Methyl group 2. (CH²)¹⁴ is a hydrocarbon chain 3. COOH is a Carboxylic-acid group |
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What symbol can fatty acids be abrieviated to? |
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What is the structure of Glycerol? |
C²H⁵OH³ |
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What is different about the structure of a unsaturated fatty acid? |
Contains a double bond in the hydrocarbon chain |
e.g. Palmitaleic acid CH²(CH²)⁶CH=CH(CH²)⁶COOH |
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What symbol can unsaturated fatty acids be abrieviated to? |
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Why are unsaturated fatty acids bent? |
Not all of the carbons are fully bonded to hydrogen (the double bond is between two carbons) |
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Why are saturated fats solid at room temperature? |
Straight chains allow them to condense |
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Why are unsaturated fatty acids liquid at room temperature? |
Bent chains are harder to condense |
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How are triglycerides formed? |
When the carboxyl groups of 3 fatty acids react with the hydroxyl groups of Glycerol in a condensation reaction releasing 3 water molecules and forming ester (covalent) bonds |
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What are ester bonds? |
Strong covalent bonds |
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What are phospholipids? |
Glycerol with 2 fatty acids and a negatively charged phosphate group bonded in the same structure of triglycerides |
Similar to the structure of triglycerides |
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What shape do phospholipids form in a closed system? |
Sphere |
Phosphate is hydrophilic whilst fatty acids and Glycerol are hydrophobic |
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What do phospholipids form in a cell membrane? |
Bilayers where the hydrophobic fatty acids point inwards and the hydrophilic phosphate points outwards |
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What is the test for lipids? |
1. Add ethanol then mix 2. Add water (after to avoid seperating) 3. White emulsion is a positive result |
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