Lipids - 3.5 - (2) Flashcards
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What is meant by the term ‘saturated’?
this is where fatty acid chains have no double bonds present between the carbon atoms
Why are the fatty acid chains saturated?
because all carbon atoms form the maximum number of bonds with hydrogen atoms
What is meant by the term ‘unsaturated’?
this is a fatty acid with double bonds between some of the carbon atoms
If there is just one double bond, what is it called?
monounsaturated
If there are two or more double bonds, what is this called?
polyunsaturated
What do the presence of the double bonds cause the molecule to do?
to kink or bend and then they cannot pack so closely together
What does this make them at room temperature and how are they described?
liquid at room temperature rather than solid, and they are described as oils
What do plants contain?
unsaturated triglycerides that normally occur as oils and tend to be more healthy in the human diet than solid fats
What has there been some evidence about in excess, saturated fats?
it can lead to coronary heart disease, although this evidence remains inconclusive
What can lead to obesity and put a strain on the heart?
an excess of any type of fat
What are phospholipids?
they are modified triglycerides and they contain the element phosphorus along with carbon, hydrogen, and oxygen
Where are inorganic phosphate ions (POv4^3-) found?
in the cytoplasm of every cell
What has extra electrons?
the phosphate ions and they are negatively charged - this makes them soluble in water
What is replaced with a phosphate group to make a phospholipid?
one of the fatty acid chains in a triglyceride molecule
Why are phospholipids unusual?
because of their length, they have a non-polar end or tail (the fatty acid chains) and a charged end or head (the phosphate group)
What are the non-polar tails repelled by?
water
Are the non-polar tails hydrophobic or hydrophilic?
hydrophobic
Describe the charged heads
they will interact with, and are attracted to, water and they are hydrophilic
What is the difference between a triglyceride and a phospholipid?
one of the fatty acids is taken away and is replaced by a phosphate molecule
