Waxes
- An ester formed between two fatty acids. Secreted from sebaceous glands for protection, bees make it
fatty acid-saturated vs unsaturated
- Carboxyl group with long carbon backbone attached. Saturated has no double bonds, while unsaturated has double bonds.
Saturated and unsaturated fats to know
- Saturated
o Palmitic acid – 16C – CH3(CH2)14COOH
o Stearic acid – 18C – CH3(CH2)16COOH - Unsaturated
o Oleic – 18C – 1 double bond at carbon 9 (omega 9)
o Linoleic – 18C – 2 double bonds, one at 9 and one at 12 (omega 6)
o Linolenic – 18C – 3 double bonds, one at 9, 12, and 15 (omega 3)
an “omega-3, or omega 6
- Has the first double bond 3, 6, or 9 carbons from the omega carbon (last C)
What is the difference between a fat and an oil?
- Fats – solid triglycerides – contain high proportion of saturated fats.
- Oils – liquid triglycerides – contain high proportion of unsaturated fats.
Are most double bonds in unsaturated fatty acids found in animals cis, or trans?
- cis
hydrogenation and what effect this has on lipids.
- Adding H atoms to an unsaturated fatty acid. This can result in trans fats.
Where do most trans fatty acids come from in our diets? What physical properties do trans fatty acids have in common with saturated fats?
- Processed foods. They are straight, like saturated fats so they stack well but don’t get broken down easily.
When you hydrolyze oils or fats with a base, what happens? What is this called?
- Soaps are formed. Saponification
Know how soaps and detergents work.
- They have a hydrophilic end and a hydrophobic end. The hydrophobic end reacts with fats, then gets dissolved in water in micelles.
lipids in cellmemembrane
- Glycerophopholipid – amino alcohol - phosphate - glycerol - 2 fatty acid chains
o Very abundant in most cell membranes - Sphingomyelin – amino alcohol – phosphate – sphingosine – 1 fatty acid (via amide)
o Along the spinal cord - Glycolipic – sugar – sphingosine – 1 fatty acid (via amide)
o In the brain
cholesterole and steroidsturcture
- Cholesterol makes up about 1/3 of cell membranes. Provides rigidity.
- Steroids have 3 6 fused 6 carbon rings as well as a 5 carbon ring.
What is the major function of cholesterole
- Provide rigidity to cell membranes
fluid-mosaic model
integral, and peripheral membrane proteins
- Integral goes into the hydrophobic portion of membrane
- Peripheral just interacts with the lipid heads.
different types of transport across membranes
o Simple occurs because of osmosis. Only nonpolar molecules
o Facilitated occurs through a protein channel, without energy
Active – runs against a gradient and required energy
three major types of eicosanoids
leukotrienes: three conjugated double bonds
- Cause inflammation, trigger asthmatic response and allergic reactions
Prostaglandins: cyclopentane ring
- Stimulate uterine contractions, induce labor and cause inflammation
- Targeted by aspirin, blocks the formation from arachidonic acid
thromboxanes: six-membered cyclic ether- ring
