lipids

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  • Created by: lauraxxx
  • Created on: 08-01-15 09:46
What are the charecteristics of a lipid?
1.Contains cardon,hydrogen&oxygen. 2. The proportion of oxygen to carbon&hydrogen is smaller than in a carb. 3.Insouble in water. 4.Soluble in organic solvents e.g.alcohol and acetone
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What are the mai lipid groups?
Triglyceridies (fats and oils), phospholipids and waxes
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What are the roles of lipids?
An energy source-Oxisedised provide more energy than carbs Waterproofing-insouble,plants have waxy cuticles and mammals secreate in from skin glands. Insulation-slow conductors of heat,esp. when under skin. Protection- surround organs e.g. liver
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How does a triglyceride form?
3 fatty acids are combined with 3 glycerols by forming a bond in a condensation reaction.
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Where do the variatios in fats and oils come from?
There are over 70 fatty acids with differene -COOH chains
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When is a fatty acid classed as saturated?
has no carbon-carbon double bonds because all of the carbons are linked to the maximum number of hydrogen atoms
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When is a fatty acid mono-unsaturated?
If there is a single,double carbon-carbon bond
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What is a fatty acid polyunsaturated?
More than one double carbon-carbon double bond
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What makes phospholipids different from lipids?
One of the fatty acids is replaced by a phosphate molecule
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What two parts is a phospholipid made of?
a hydrophilic head - attracted to water but not fat and a hydrophobic tail - orinets it's self away from water but mixes with fat. Theyre polar
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What is the test for lipids?
1.dry&grease free test tube. 2. 2cm3 of sample and 5cm3 of ethanol. 3.shake tube throughly to dissolve away lipids. 4. add 5cm3 of water and shake. 5.cloudly white indicates lipid 6.as a control repeat with water instead of food sample
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Why does the mixture turn cloudy if lipids are present?
Due to the lipids being finely dispersed light passing through this emulsion is refracted as it passes from oil droplets to water droplets making it appear cloudy
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Other cards in this set

Card 2

Front

What are the mai lipid groups?

Back

Triglyceridies (fats and oils), phospholipids and waxes

Card 3

Front

What are the roles of lipids?

Back

Preview of the front of card 3

Card 4

Front

How does a triglyceride form?

Back

Preview of the front of card 4

Card 5

Front

Where do the variatios in fats and oils come from?

Back

Preview of the front of card 5
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