Lecture 5 Flashcards
why are lipids hydrophobic?
because they have hydrocarbon chains
they are soluble in non-polar solvents (ether and chloroform)
what are the 4 types of lipids and name their characteristics
1) triglycerides = water insoluble
2) fatty acids = water insoluble
3) steroids = membrane component, hormones
4) phospholipids = amphipathic, membrane component
what is the main function of fats?
energy storage
also insulation against cold, cushion for injury
what are the two small molecules that triglycerides are made up of?
1) fatty acids (3)
2) glycerol
name
glycerol
name
fatty acid
what is an ester linkage?
3 fatty acids joined to 1 glycerol molecules through these bonds.
linkages in triaclyglycerol
what are the three types of fatty acids?
1) saturated
2) monounsaturated
3) polysaturated
mono, poly, saturated fatty acids
what is the difference between the types of fatty acids?
1) saturated = max # of hydrogen bonds with no double bond
2) monounsaturated = one double bond, liquid at room temperature
3) Polysaturated = contains more than one double bond, liquid at room temperature
what type of shape can unsaturated fatty acids occur in?
trans or cis
what type of unsaturated fatty acid is this?
trans
what type of unsaturated fatty acid is this?
cis
what are hydrogenated fats?
fats in which hydrogen atoms have been added to unsaturated fatty acid chains during the process of hydrogenation. This process converts cis-bonds into trans-bonds
example of margarine having more trans fatty acids than butter
what is the use of bile salts made by the liver?
bile salts are used in the digestive tract that break down large fats
Explain the process of the digestion of triglycerides
fats are hydrolyzed into fatty acids to be absorbed into the mucosal cells of the inner wall of the small intestine. These are then reassembled and packaged into lipoproteins called chylomicrons. These chylomicrons enter the blood to deliver fats to the cells of the body.
Simple terms:
1) fatty acids broken down in small intestine
2) bile salts from liver break down large fats
3) enzymes break down triglycerides
4) broken down triglycerides become lipoproteins that get stores in hollow spheres called chylomicrons
5) these chylomicrons are distributed to the rest of the body
what are chylomircons?
hollow spheres that store lipoproteins which get distributed throughout the cells of the body
- have a hydrophobic interiror
- have a hydrophilic exteriror
what are VLDLs?
very low density lipoproteins
what is this process?
the breakdown and digestion of triglycerides and the distribution of lipoproteins in chylomicrons to the cells of the body
what are steroids and name two.
steroids are 4 interconnected hydrocarbon rings with various functional groups attached.
ex: testosterone and cholesterol
what are anabolic steroids?
steroids used to promote muscle growth
how is cholesterol transported in the blood?
by lipoproteins (LDL and HDL)
what is considered bad cholesterol?
diets that are high in trans fats that impede the uptake of low density lipoproteins by cells which cause the low density lipoproteins to continue circulating the blood.
the more LDL you have circulating the blood, the higher the risk of blocked arteries = atherosclerosis
what is considered good cholesterol?
the amount of high density lipoproteins circulating the blood; HDLs pick up excess cholesterol and take it to the liver to get processed which reduces the amount of cholesterol in the blood.
what does it mean when you have a higher ratio of LDL/HDL?
higher risk of cardiovascular disease
