Lipids, Trace Elements, Vitamins Flashcards
lipoproteins
substances composed of lipids and proteins in varying concentrations
what are the major lipoproteins?
chylomicrons, VLDL, LDL, HDL
chylomicrons
lipoprotein that contains apo B-48 and is the largest and least dense of the lipids and accounts for the turbidity in postprandial plasma
where are chylomicrons produced?
in the intestine from dietary lipids
what are chylomicrons mostly composed of?
triglycerides
what is the function of a chylomicron?
to transport dietary triglycerides throughout the circulatory system to peripheral tissues
where are VLDLs produced?
mainly by the liver
what is the function of VLDL?
to redistribute dietary and hepatic-synthesized triglycerides to peripheral cells mostly during fasting for energy needs or storage as fat
how is LDL formed?
from the lipolysis of VLDL
what is the function of LDL?
to deliver cholesterol to peripheral cells
how is HDL synthesized?
by the liver and intestine
what is the function of HDL?
removes excess cholesterol from peripheral cells for metabolism by the liver
atherosclerosis
disease in which there is an accumulation of lipid material in the veins and arteries, causing the arteries to narrow and harden
dyslipidemias
disease states associated with abnormal serum lipids usually caused by malfunction in synthesis, transport, or catabolism of lipoproteins; may be caused by either elevated or decreased lipoprotein levels
lipids
fats found in all living cells that are a rich source of energy, are an efficient way for the body to store excess calories, and have a structural role in cells as an integral part of cell membranes
what lipids are transported by lipoproteins?
triglycerides, phospholipids, cholesterol, cholesteryl esters
phospholipids
amphipathic lipids molecules that are found on the surface of lipoprotein molecules
fatty acids
linear chains of carbon-hydrogen bonds that terminate with a carboxyl group
what are most fatty acids in plasma a constituent of?
triglycerides and phospholipids
what are triglycerides composed of?
three fatty acid molecules attached to a glycerol backbone
what are phospholipids composed of?
two esterified fatty acids and a phospholipid head group on a glycerol backbone
cholesterol
an unsaturated steroid alcohol found on the surface of lipid layers; an amphipathic lipid synthesized almost exclusively by animals
where is cholesterol synthesized?
in most tissues of the body from acetyl coenzyme a
structure of lipoprotein
- amphipathic cholesterol and phospholipid molecules are found on the surface of lipoproteins
- hydrophobic and neutral triglyceride and cholesteryl ester molecules are found in central or core region
what is the main role of lipoproteins?
to deliver fuel to peripheral cells
