Ch 3 Biochemistry 3-2: Lipids & Nucleic Acids Flashcards
What are lipids?
nonpolar organic molecules containing carbon, hydrogen, and oxygen
What are the functions of lipids?
- store energy
- important part of cell membranes
- provide insulation
What are fatty acids?
the monomer of a lipid. they are also unbranched carbon chains (from 12-28 carbons) that attach to a carboxyl group (-COOH)
What is the difference of properties between the two ends of a fatty acid?
the carboxyl (-COOH) end is polar and therefore hydrophilic or “water loving. the rest of the lipid molecule is nonpolar and therefore hydrophobic or “water fearing”
How is carbon bonded in saturated fatty acids?
carbon is covalently bonded to four atoms, with no double bonds between theme.
How is carbon bonded in unsaturated fatty acids?
carbon can form one or more double bonds within the fatty acid chain
What are the three classes of lipids that are important to living things?
triglycerides (fats), phospholipids, and waxes
Where are triglycerides (fats) found?
meat, butter, cheese, corn oil, olive oil, canola oil, etc.
What are saturated triglycerides?
they are composed of saturated fatty acids and are usually solid at room temperature. they can cause the build-up of plaque in blood vessels leading to cardiovascular diseases.
What are unsaturated triglycerides?
formed from unsaturated fatty acids and are liquid at room temperature. they are found mainly in plant seeds and are easier to digest and have less chance of a chance for causing cardiovascular diseases.
What are hydrogenated fats?
they start out as unsaturated oils but have extra hydrogen atoms added to them to produce a more stable fat and a solid (better for food manufacturing but makes them just as unhealthy as saturated fats)
What are transfats?
they come from the hydrogenation of liquid fats, and are the most dangerous of all.
What makes up cell membranes?
a double layer of phospholipids that are called the phospholipid bilayer
Why are lipids a good barrier between the inside and outside of the cell?
they are nonpolar so they do not dissolve in water
What are waxes?
Waxes are waterproof lipids that form protective coatings on plant surfaces and they also protect animal surfaces, like the earwax in our ears.
