Lipids Flashcards
Lipids are _____
esters formed by acids and alcohol
They are not true polymers
Types of Lipids
1)Triglycerides (Fats and oils)
2)Phospholipids
3)Steroids
4)Prostagladin
Fat soluble vitamins are also lipids(vit A,D,E,K and carotenoid)
What is difference b/w fat and oil?
Fats-solid at room temperature
Oil-liquid at room temperature
They are very similar in structure (triglycerides)
Triglycerides contains _____ and _____
glycerol(alcohol)
3 fatty acids(acid)
glycerolမှာOH gpသုံးခုပါတော့ COOH goသုံးခုနဲ့ပေါင်းနိုင်(ester bond သုံးခုဖြစ်)
What is fatty acid?
Carboxylic acid containing CARBOXYL GP(-COOH) and with 16-18 hydrocarbon tail
carboxyl gp-polar
hydrocarbon tail-non polar
Types of fatty acid
1)Saturated fatty acid-no double bond in hydrocarbon chain
2)Unsaturated fatty acid-double bond in hydrocarbon chain
-monounsaturated:one double bond
-polyunsaturated:many double bond
3)Hydrogenated fatty acid-adding hydrogen into unsaturated fatty acid to produces saturated fatty acid
How fat is formed?
by condensation reaction
OH gp of Glycerol and COOH gp of acid linked by ESTER BOND (removal of water)
What are saturated fat?
Glycerol+ saturated fatty acid
eg.animal fats (solid at room temp)
What are unsaturated fat?
glycerol+ unsaturated fatty acid
eg.plant and fish fats( liquid at room temperature)
Triglycerides are insoluble in ____ and soluble in _____
water(polar)
non polar solvents
glycerol ကhydrophilicဖြစ်ပေမဲ့ fatty acidကoverall hydrophobicမလို့
Function of triglycerides
energy storage for long term(in adipose and muscle cells)
Triglycerides-anhydrous & highly reduced molecules (ဖြိုခွဲရင်energyအများကြီးထွက်)
d/s caused by eating diet with many saturated fats
CVS d/s (atherosclerosis)
d/s causing eating with diet of trans fat(hydrogenated)
coronary disease
Phospholipids contain____,_____,_____ and ______
Glycerol (polar)
2 fatty acid (nonpolar)
Phosphate gp (polar)
Alcohol gp (polar)
Overall negative charged
Why phospholipids are amphipathic molecules?
They contain hydrophobic tail(glycerol+fatty acid) but hydrophilic head (phosphate gp)
In aqueous,phospholipids act as _____
lipid bilayer
-hydrophilic head outside
-hydrophilic tail inside
Function of phospholipids
major part of cell membrane (semipermeable)
How fats are digested?
b/c they are insoluble and can’t be absorbed by small intestine.in order to digest fat
1)bile salts from liver emulsified fat
2)Lipase from small intestine breakdown triglycerides into monoglyceride and 2 fatty acids
Steroids contain_____ attached to _____
four fused rings(hydrocarbonမလို့ hydrophobic)
OH gp(hydrophilic)
Many steroids are binds to alcohol and formed STEROL
Example and functions of steroid
Cholesterol
-part of the cell membrane
-precursor for other steroids,bile salts and vit D
Cholesterol are synthesized in ____ and also obtained from diet
liver
Diet with high lvl of cholesterol can cause ____
atherosclerosis
Prostaglandin are derived from____
unsaturated fatty acid (20C in 5 ring)
Function of prostaglandin
enhancing immune system and inflammatory system
Types of phospholipids
1)Phosphoglycerides
2)Sphingolipids
Phosphoglyceride contains______ as backbone
glycerol alcohol
Sphingolipids contain _____ as backbone
sphingosine alcohol (more complex primary alcohol)
Phosphoglycerides contain ______ ,______ and ________
glycerol backbone
2 fatty acids
phosphate gp
C1 and C2 are attached to F/A and C3 is linked with phosphate gp
simplest phosphoglyceride is ______
phosphotidate (less common)
C3 binds to Oxygen which is attached to phosphate (unmodified phosphate gp)
Modified phosphate gp are _____,______ and _____
choline
serine
inositol
What is the most common phosphoglycerides in cell membrane?
Phosphotidylcholine (phosphtidate+ choline)
Double bond in unsaturated fatty acid are ____
cis bond -2 gps attached to the carbon are same side of the double bond
Hydrogenation of unsaturated fatty acid can get the fatty acid with_____ forms and _____
saturated fatty acid
unsaturated fatty acid with trans bond
(2 gps attached to the carbon are at the opposite site of the double bond)
Sphingolipid contains_____ as backbone
sphingosine alcohol
Sphingolipid contains ______ and _____ gp
sphingosine alcohol as backbone
fatty acids attached to backbone by AMIDE BOND
primary alcohol attached to phosphate gp by ESTER BOND
sphingolipids are common in _____
membrane of nerve cells(sphingomyelin)
What are animal steroids?
1)Aldosterone
2)Cortisol
3)Progesterone
4)Estrogen
5)Testosterone
Structure of triacyglycerol
One glycerol+ 3 fatty acids
Are lipids hydrophilic or hydrophobic?
Non-polar hydrocarbon chain ——> lipids are hydrophobic
What reaction involves in formation of TAG?
Dehydration synthesis reaction or condensation reaction
What are the difference between saturated and unsaturated fatty acids?
Saturated f/a
No double bonds
As many hydrogen atoms as possible
Tightly packed, solid at RT
Unsaturated f/a
One or more double bonds
1 double bond- reduce two hydrogen atoms
Cis and trans form
Cis acid-contain a kink- liquid at RT
Trans acid- no kink- solid
What kinds of lipids below are bad for health?
- Trans
- Cis
- Saturated
1 and 3 they are packly tight and solid at room temp.
Can cis acid be transformed to trans acid?
Yes. By partial hydrogenation.
Partial hydrogenation occurs in digestive tract of animals such as cows. Therefore- fat in meat are trans fat
How are fatty acid classified according to the type of bonds?
Monounsatured and polyunsaturated fatty acids
In poly unsaturated fatty acids, the double bonds are counted from the omega end of the fatty acid (methyl end)
What are essential fatty acid?
Nutritionally important for the body and cannot be synthesized in the body
Esssential fatty acids are omega 3 and omega 6 fatty acids
Omega3-ALA,DHA,EPA
Omega 6-linoleic acid, Arachidonic acid
Is omega 9 mono or polyunsaturated fatty acid?
Monounsaturated fatty acid
Eg Oleic acid
THEY ARE NOT ESSENTIAL FATTY ACIDS
According to the length of the fatty acid, how are they classified?
Short chain fatty acid- 3 to5 carbon atoms
Medium chain fatty acid- 6 to 12 carbon atoms
Long chain fatty acid-more than 13 carbon atoms
Phospholipids structure
Phosphate+glycerol+2 fatty acids
R group attached to phosphate group
Eg. Phosphoditylcholine and phosphotidyl serine are common PL in plasma membrane.
Is phospholipid soluble in water?
They have amphipathic property both water loving and water hating because phosphate-polar, fatty acid chain-non polar
Steroid structure
Four carbon rings ( 3 of them- 6 carbon ring+1 of the carbon ring- 5 carbon) and contain an OH group because they are sterols (alcohols)
The most common steroid
Cholesterol.
Cholesterol is the precursor of sex hormones(estradiol and testosterone)
Vitamin D
And bile salts for emulsification of fat)
Name what types of lipids are they?
Palmitic acid stearic acid, Oleic acid , arachidonic acid
Palmitic acid-saturated
Stearic acid-saturated
Oleic acid- monounsaturated acid Arachidonic acid-polyunsaturated
Are steroids soluble in water?
No.
They are lipids
