3.8-3.11 Flashcards
Important factors in lipids.
Hydrophobic (nonpolar). Not macromolecules. Not polymer.
What are three important types of lipids?
fats, phospholipids, steriods.
Define fat
large lipid made up of glycerol and fatty acids. Brought together by dehydration synthesis from an H atom connected to a hydroxyl group in glycerol and the O and H in the hydroxyl group in the carboxyl group in the fatty acids. (a mouthful look at pg. 40)
What is glycerol?
three carbons, each with hydroxyl group (OH), and another hydrogen.
What are fatty acids?
carboxyl group (-COOH) attached to a hydrocarbon chain.
What is a hydrocarbon chain?
CH2
|
CH2
|
CH2…
for 16-18 of those. The bonds, actually C-H, are nonpolar.
Define triglyceride
a synonym for fat. Happens when three fatty acids are linked to a glycerol, “filling” the glycerol.
Define unsaturated fatty acid.
a fatty acid whose hydrocarbon chain contains one or more double bonds (between Carbons- one fewer hydrogen atom). liquid at room temp because they cannot bond tightly together (because of kinks)
What do double bonds cause in hydrocarbon chains?
kinks/bends
Define saturated fatty acid
has the maximum number of hydrogen atoms attached to carbon in hydrocarbon chain. Solid at room temp.
where are saturated fats naturally occurring?
in animals; fat in meat and butter.
where are unsaturated fats naturally occurring?
in fish in plants. Ex. salmon, vegetable oil.
Define trans fat
when hydrogenating (adding hydrogen) to a fatty acid– causing some health risks.
What is the main function of fats?
long-term energy storage. Fat is much more effective in storing energy than sugar.
phospholipids are a major component of the ____________
cell membrane
How are phospholipids constructed?
Two hydrocarbon chains attached to the carbons in a glycerol (see pg. 42). The third carbon is attached to the (negatively-charged) phosphate group. Unsaturated sometimes
How does form fit function, in phospholipids?
The two ends of a phospholipids (tail and glycerol+phosphate group) have different relationships with water, resulting in the aggregation of multiple phospholipids molecules into a membrane. The hydrophobic tails (nonpolar) of fatty acids are clustered together in the center, excluded from the water, and the hydrophilic phosphate heads face the watery environment on either side of the membrane.
Define steriods.
lipids in which the carbon skeleton contains four fused rings, connected to a hydrocarbon tail. Ex. cholesterol.
Define cholesterol.
C27H46O. it is a common component in animal cell membranes and the precursor for other steroids, including sex hormones. Too much –> atherosclerosis.
What are anabolic steroids?
synthetic variants of the male hormone testosterone. Used for fast muscle buildup.
What are the downside of anabolic steroids?
causes violent mood swings, depression, liver damage, cancer, high cholesterol and blood pressure. Disrupts normal cycles of puberty.
Explain why fats and steroids, which are structurally very different, are both classes as lipids?
Fats and steroids are hydrophobic molecules, the key characteristics of lipids.
How do other steroids vary from cholesterol?
in the chemical groups attached to the fused rings.
