Week 3 - Lipids Flashcards
What are lipids
Organic compounds which are insoluble inwater but soluble in organic solvents
A heterogenous class of naturally occurring organic compounds classified together on the basis of common solubility properties that they are:
- insoluble in water but soluble in organic solvents including diethyl either benzene and CHCl3/MeOH
Where are lipids in Dentistry
Saliva - is compose of fatty acids, triglycerides, glycerophospholipids, sphingolipids and cholesterol and the ratio of these lipids change during diseases indicating the presence of that disease.
Dental Calculus -The calculus is formed by hardening of dental plaque. The organic content of the dry matter is 54.9% protein and 10.2% lipid
What are the functions of lipids (5)
- Structural component of cell membranes*
- Intracellular storage of metabolic fuel
- Transport of metabolic fuel*
- Insulating material
- Chemical Signaling*
How are lipids structural components of cell membrane
The cell membrane is primarily composed of a semipermeable bilayer of glycerophospholids(Lecithin) which contains embedded cholesterol and sphingolipids. This contains the flow of molecules in and out of the cell and allows cell to cell communication/reception
How are lipids intracellular storage of metabolic fuel
Lots of energy is stored in the body in the form of lipid (triglycerides/triglycerols). Stored in fat cells called adipocytes.
How do lipids transport metabolic fuel
Lipoproteins transport lipids(cholesterol, triglycerides, phospholipids) to different areas of the body.
How are lipids insulating materials
Lipids include fat (triglycerides) which is stored beneath the skin and its serves to insulate the body and prevent heat loss.
Lipids (myelin sheath) provides electric insulation around nerve fibres so that electric cells can transmit down them quickly and efficiently
How do lipids create chemical signals
Steroid hormones - are chemical messengers which allows the communication between tissues and organs of the body - signaling the production or reduced production of chemical (e.g. insulin -> glucose)
Second Messengers are intracellular signaling molecules that relay signals between the receptors and target proteins in cells
What are the type 1 lipids (Fatty acids)
- Fatty Acid (free)
- fatty acid (ester)
What are the Type 2 - lipids containing glycerol
-Triglyceride(Triacylgcerols)
- Glycerophospholipids (phosphoglycerides)
What are the Type 3 lipids - lipids not containing glycerol backbone
- Sphingolipids
- Glycolipids
- Steroids
- Lipid soluble vitamins
What are the type 4 lipids - lipids combined with other types of compounds
- Lipoproteins (HDL,LDL,VLDL)
What are fatty acids
Long chained carboxylic acids
Difference between unsaturated and saturated fatty acids
Unsaturated = only single bonded carbons
Saturated = double bonds are present resulting in bend structure
What are the fatty acid trends
- as carbon chain length increases the water solubility decreases
- as carbon double bonds increase water solubility increases
- as chain length increases melting point increases
- As C=C increase melting point decreases
What are examples of Fatty Acids (free)
- Stearic acid (18:0)
- Linoleic acid (18:2)
What are fatty acid ester
Fatty acid + alcohol = fatty acid ester
What are tiglycerides
An ester of glycerol with 3 fatty acids connected.
Where are triglycerides found
- Fat tissue (adipocyte)
- Major dietary lipid
- Major transport form (chylomicrons)
What are phosphoglycerides/glycerophospholipids
Triglycerides but instead of one of the fatty acid chains its replaced with a phosphate group (-PO4) and some sort of nitrogen group (normally an amine group)
What is an example of a phosphoglyceride/glycerophospholids
Lecithin
- phosphate group and a choline group
What is sphingolipid
Uses a sphingosine backbone
A 4 carbon chain with the side chains:
- Fatty ester
- Hydroxide (-OH)
- Amide + an extended chain (some sort of FA)
- oxygen followed by usually a phospho+amine group or a glucose molecule
Example of a sphingolipid
Sphingomyelin - covered nerve axons (myelin) acts as an insulator
What are glycolipids
A sphingolipid which has a carbohydrate (glucose) molecule attached to the final oxygen
What are steroids
Have a tetracyclic ring structure which is common to all steroids
Example of a steroid
Cholesterol
- builds the structure of cell membranes
- is the base molecule which can then be turned into other hormones (oestrogen, testosterone)
What are steroid hormones
Hormones - a substance produced by one cell system (e.g. endocrine glands) and delivered by the bloodstream to remote target system which it regulates (e.g. metabolism
Example of Steroid hormones
Androgens - responsible for development of male sex characteristics
Estrogen - responsible for the development of female sex characteristics
What are second messengers
A component within the single transduction which are intracellular signaling molecules that relay signals between receptors and target proteins
What are vitamins
Essential organic compounds that the body needs in small amount that play a crucial role in metabolism, growth, development and overall health
Example of lipid soluble vitamins
- Vitamin A
- Vitamin D3
- Vitamin E
Function of Vitamin A
- An unsaturated hydrocarbon which make it soluble in lipids
- important to vision, growth, cell division, reproduction and immunity
- formed from b-carotene which is abundant in carrots
Function of Vitamin D3
- Is a steroid derived molecule making it lipid soluble
- formed from cholesterol and UV from the sun
- the vitamin increases synthesis of a Ca+2 binding protein, increasing the calcium uptake by teeth
What are LDL
A sphere complex of lipids and proteins which transport cholesterol from the liver to peripheral tissue and helps regulate cholesterol levels.
- Has a hydrophilic surface and hydrophobic core
- If too much LDL in bloodstream it can accumulate in the walls of arteries forming plaque (bad cholesterol)
Example of a second messenger
Diacylglycerol (DAG)
Inositol 1,4,5 - trisphosphate (IP3)
What is the trend of amount of cholesterol and cholesteryl esters in lipoproteins
LDL has the most but after that
HDL has the most and chylomicrons have the least
What is the trend of the amount of triglycerides in lipoproteins
highest in chylomicrons and lowest in HDL
What is the trend for the amount of phospholipids and proteins in lipoproteins surface
Highest in HDL and lowest in Chylomicrons
what’s the enzyme that hydrolyze lipids and releases the fatty acid components
Lipases
