LECTURE 3 Flashcards
Structural polysaccharides
1) cellulose
2) chitin
Cellulose
- Polymer of glucose
- covalent 1-4 linkages involve BETA from of glucose.
- Forms straight polymers.
- Never branch
- very strong sue to hydrogen bonding
Chitin
Structural polysaccharide used by bugs (exoskeleton)
- contains N-acetylglucosamine (derivative of glucose)
- acetyl amine group instead of OH, increases hydrogen bonding, increasing strength.
Lipids
- hydrophobic
- consists of mostly hydrocarbons which are non polar.
- fats,phospholipids, steroids
Fats
Not polymers, but they are built from monomers that are added by dehydration reactions.
In a fat, three _______ ____ are joined to ________ by an _______ linkage
Fatty acids, glycerol, Ester
Fatty acids vary in
length and in number and location of bonds
Saturated fatty acids
Don’t have double bonds, making it have only H and C = saturated fat.
- solid @ room temp
Unsaturated fatty acids
One or more double bonds, cis double bonds causes blending, fats cannot pack too closely
- cannot solidity @ room temp (liquid)
Saturated fats may contribute to
Cardiovascular disease
Trans fats
- unsaturated fats
- plant oils => partially hydrogenated => many double bonds are saturated by adding H => makes plant oils solid @ room temp.
The process of making trans fats also creates
A lot of trans fats as a by-product.
- cis double bonds in plant oils become rearranged rather then saturated.
Phospholipids
Two fatty acids and a phosphate group attached to glycerol.
- phosphate group = hydrophilic
- two fatty acid tails = hydrophobic
Phospholipids are amphipathic molecules
Amphipathic molecule (phospholipids)
Having both a hydrophilic polar end and a hydrophobic non-polar end
What happens to phospholipids when added to weather and why
They rearrange into various structure because of their amphipathic nature
What makes up the main fabric of biological membranes
Bilateral structures
