DLA #3: Lipids Structure/Function Flashcards
Lipids are insoluble in
Water
Lipids are soluble in
Organic Solvents
What are the three general classes of lipids
-simple -complex -derived
Give an example of a simple lipid
Triacylglycerol (TAG)
What is Triacylglycerol (TAG)
It is a storage lipid
Give one word to explain Triacylglycerol (TAG) response to water
HYDROPHOBIC
For a lipid to be classified as a complex lipid, it must
contain non-lipid components
How do derived lipids exist
Via hydrolysis of simple and complex lipids
Give examples of derived lipids
-Fatty acids -Cholesterol
Cholesterol and Complex lipids are considered to be _________ which means _________
-Amphipathic -They contain both a hydrophilic and hydrophobic parts
Describe fatty acid chemically.
A long carbon chain containing a methyl group on one end and a carboxyl group at the other.
In medicine the standard nomenclature for fatty acids is omega. Please explain what this means.
At the methyl end of the fatty acid chain, the carbons are counted until we reach the first double bond.
Unsaturated fatty acids chemically contain
Fatty acids that contain a double bond
Ex) Monounsaturated Fatty Acids (MUFA) and Polyunsaturated Fatty Acids
Saturated fatty acids chemically contain
No double bond
Give examples of saturated fatty acids.
-Palmitic Acid and Stearic acid.
***Stearic hinderance is when a compound cannot freely rotate. Saturated acids are very packed and can’t freely move
****People under palm trees get saturated in oil.
What are things we consume that are saturated fatty acids.
Butter, Coconut oil, Animal fat
B/c saturated fatty acids do not have kinks in their carbon chain this causes
Close packing and lower membrane mobility
A reduction of saturated fatty acids in a patients diet is important in maintaing
Cardiovascular health
Prescence of unsaturated fatty acids in a pm causes
Packing to be NOT as tight and fluidity to be present
An example of a monounsaturated fatty acid is:
-Oleic Acid (found in olive oil)
“Mediterranean diet”
We expect that the fluidity of Polyunsaturated fatty acids would be ________ than Monounsaturated b/c
Greater b/c polyunsaturated fatty acids contain multiple double bonds in their carbon chain
Name the polyunsaturated fatty acids
- omega-3: a-linolenic acid, eicosapentaenoic acid and DHA
- omega-6: linolenic acid and arachidonic acid
When in comes to omega-3 and omega-6, physicians recommend:
More omega-3, less omega-6
What polyunsaturated fatty acid is derived from plant oil and why is that important
- Omega-6 (Linoleic Acid)
- Important we get them from plant oil b/c they are essential fatty acids
Arachidonic Acids is derived from
Linoleic Acid.
=>Linoleic Acid is desaturated (added more double bonds) and elongated (add C)
Arachidonic Acid is a precursor to ______ which mediate _______
Prostaglandins, inflamatory response
Alpha-linolenic acid is considred to be a
Essential fatty acid.
ALA is a precursor to
ALA => EPA => DHA
Eicosapentaenoic acid (EPA) is important b/c
It’s cardiorotective
Docosahexaenoic acid (DHA) is important b/c
Its important for myelination and neural/brain development.
Also vision.
What are classic sources of omega-3 in our daily diet
- Fish
- Fish oil
What are the two essential fatty acids.
linoleic acid and alpha linoleic acid
“the TWO Losers”
Deficiency of fatty acids (people with fat free diet):
Causes:
-Dry skin and hair loss.
***Helpful tip: Vishal is Hindu. Hindu culture can stem away from selective fatty acids. Vishal has dry elbows and balding.
Trans fatty acids act
- Very similar to saturated fatty acids.
- Have limited mobility
Trans fatty acids increases ________
-LDL Cholesterol and risk of heart disease.
In our diet trans fats are found in
Margarine, fried foods, baked goods
Chemically describe cholesterol
- Steroid ring
- Amphipathic lipid:
=>OH group [hydrophilic]
and
=>Steroid ring [hydrophobic]
Cholesterol in storage form is called
Cholesterol ester
Where is cholesterol found on the pm
Cholesterol is located on both the inner and outer leaflets
Functions of cholesterol
- Cell/plasma membrane
- Precursor to bile
- Precursor of steroid hormones
- Precursor of Vit D in skin
Describe Triacylglycerol chemically:
In adipose tissue, TAG is important b/c
- Its is the strorage form of energy in the tissue.
- Highy hydrophobic
- Oxidized during fasting state.
If a complex lipid has a carbohydrate as its non-lipid component, we call this a:
Glycolipid
If a complex lipid contains phosphate as its non-lipid component, we call this lipid a
Phospholipid
Phospholipids are further subdivided into:
1) Glycerophospholipids
2) Sphingophospholipids
**Note sheet tagged
General structure of complex lipids are
- Hydrophilic head
- Hydrophobic tail
Compostion of glycerophospholipids
- Polar head group comprised of phosphate. Attached to glycerol
- Two nonpolar fatty acid tails. Each attached to glycerol
Phosphatidic acid is considered the
Building block of phospholipids
Not found in the cell membrane. Is in the intermediate
Name the four examples of glycerophospholipids
What distinguishes these lipids from one another
They all have phosphate, glycerol and fatty acid tails. However, there bases vary.
Image does not have it but CARDIOLIPIN is also one as well.
Where is cardiolipin found.
Cardiolipin is a glycerophospholipid that is found in the inner mitochondiral membrane
Name the function/significance of Phosphatidylcholine (Lecithin):
Found on the outer leaflet of the cell membrane.
Modified to DPPC (Dipalmitoylphosphatidlycholine) => the phospholipid that makes up surfactant.
What is the name of the cells that produce surfactant called.
Type-ll cells
What is the function of surfactant
Lines the inner surface of the alveolus in order to reduce surface tension. This prevents the alveolus from collapse.
What happens if surfactant is not being produced efficiently.
- Respiratory distress syndrome.
- During RDS, alveolus collapses on one another.
- Seen in smokers due to type-ll cell damage and also seen by premature birth.
What is the lecithin-sphingomyelin ratio?
- Way in which physicians can check how well a fetal lung has developed.
- Can be done by measuring the amniotic fluid in order to measure the quantity of lecithin.
ratio > 2 good
ratio < 1.5 bad
Name the function/significance of phosphatidylserine
=>glycerophospolipid that is found initially on the inner leaflet. During cell death it is transferred to the outer leaftler via enzymes in order to signal for apoptosis
Name the function/significance of phosphatidylinositol
Is a glycerophospholipid, found on inner leaflet of membrane, aid in production of second messenger.
Ex) DAG, IP3
Name the function/significance of phosphatidylethanolamine
Inner leaflet of the cell membrane
In general, the chemical stucture of sphingophospholipids are:
Phosphate choline head
Fatty acid and sphingosine tails
What is sphingomyelin
Is a type of sphingolipid.
Found on the outer leaflet of cell membrane
Forms myelin sheath around neurons
-In general, the chemical compostion of glycolipids are:
- Sphingosine w/fatty acids.
- AND VARYING CARBOHYDRATES
ALL GLYCOLIPIDS DISCUSSED IN TERM 1 ARE FOUND IN:
-OUTER LEAFLET
What is the composition of cerebrosides
Sphingosine + Fatty Acid + Monosaccharide
-Type of Glycolipid
What is the composition of sulfatide
Sphingosine + Fatty Acid + Monosaccharide + Sulfate
-Type of Glycolipid
What is the compostions of Globoside
Sphingosine + Fatty Acid + Oligosaccharide
-Type of Glycolipid
What is the composition of a Ganglioside
Sphingosine + Fatty Acid + Oligosaccharide (w/ NANA)
BUILD UP LEADS TO TAY-SACHS DISEASE
-Type of Glycolipid
