11. Lipids and Lipoproteins Flashcards
What are the 4 roles of lipids?
- Source of energy
- Integral part of cell membrane that assist cell structure
- Converted to hormones or hormone precursors
- Insulators for nerve conduction and heat retention
What are the 6 different types of lipids?
- Fatty acids
- Triglyceride
- Phospholipids
- Cholesterol
- Cholesteryl esters
- Apolipoprotein
Are lipids soluble or insoluble in water?
Insoluble
Fatty acids are an integral part in what kinds of lipids (2)?
Triglycerides and phospholipids
Fatty acids can be acquired by
Body can make some fatty acids, and there are essential fatty acids acquired by diet
Fatty acids are composed of (saturated vs unsaturated)?
Fatty acids are long carbon chains joined by single (saturated) or double bonds (unsaturated) and a terminal carboxyl group
What is triglyceride composed of?
Composed of 3 fatty acids and a glycerol molecule
Triglycerides comprises what percentage of fat stored in tissue?
Triglycerides comprises 95% of fat stored in tissue
Triglycerides can be exogenous or endogenous, or both?
Triglycerides can be exogenous (come from diet, plant/animal sources) or endogenous (synthesized by body)
What are phospholipids composed of? What is a term used to describe phospholipids?
Composed of two fatty acid molecules (hydrophobic) and a hydrophilic head (phosphate-containing group attached to a glycerol molecule)
Amphipathic (has both hydrophobic and hydrophilic parts)
Lipids are produced in the
Liver
What is the function of phospholipids?
Crucial for formation of permeability of cell membrane
Cholesterol can be acquired exogenous. They are found in plant products, animal products, or both?
Cholesterol can only be found in animal products
What are the 4 functions of cholesterol?
- Promote fat absorption in intestine by forming bile acids
- Make hormones
- Transforms Vitamin D in skin
- Component of cell membranes
Cholesterol can be made in the body (endogenous). How?
Produced in the hepatocytes, generated from acetyl-CoA
Most serum cholesterol is in the form of ___________
Cholesterol esters
Where are cholesterol esters located?
They are located in the center of lipoproteins (high-density lipoprotein (HDL), low-density lipoprotein (LDL))
What are lipoproteins and what is their function? What is the difference between apolipoprotein and lipoprotein?
Group of soluble proteins that combine with varying amounts of lipids in the blood, for transportation. Apolipoproteins are proteins that bind lipids to form lipoproteins.
What are the different lipids in a lipoprotein (5)?
- Apolipoproteins
- Triglycerides + 3. cholesterol ester
- Phospholipid
- Free cholesterol
What are the four major categories of lipoproteins from largest to smallest?
- Chylomicrons
- VLDL: very low density lipoproteins
- VDL: low density lipoproteins
- HDL: high density lipoproteins
Which lipoprotein is the largest?
Chylomicron
Why is chylomicron the least dense lipoprotein?
They have the lowest protein-to-lipid ratio (being about 90 percent lipid) and therefore the lowest density.
Chylomicron is mostly composed of?
Triglyceride
VLDL is composed of what?
Half is composed of triglycerides, and equal amounts of phospholipids and free cholesterol, and some apolipoproteins