bio chemistry كيمياء حيوية جامعة الملك سعود chemistry كيمياء جامعية 0503964728 محمد منير كيمياء ابو يوسف all branched of chemistry bio chemistry - organic chemistry - inorganic chemistry - analytically - spectra - d-block

1. Biochemistry
١
Bio Chemistry
Lipids
 Lipids are organic compounds characteristic by their insolubility in
water (All Lipids are hydrophobic) and their solubility in
organic solvent So, extracted from tissues by non-polar solvents..
 essential source of energy.
 main component of cell membrane.
 Lipids are transported in blood as large macromolecules
•Functions of lipids in the body:
1. it’s source of energy.
2. It's stored energy in the body .
3. Contain essential fatty acids .
4. Carrier of fat soluble vitamins .
5. It's thermal / electrical insulator .
6. Lipoproteins = lipid + protein = Transport of fat soluble
substances.
7. Types:-
1) LDL = low denisty lipoprotein .
2) HDL = high denisty lipoprotein
8. structre proparites of lipiid
Classification of lipid
CLASSIFICATION
1- Simple Lipids : non – polar + energy storage
Simple lipids can be segregated into structural types, which are fatty
acids (FA), waxes, triglycerides (TG), and sterols.

2. Biochemistry
٢
Complex Lipids : polar lipid
They are lipids derived from above groups after hydrolysis (fatty
acids ) .
*.* type of simple lipide :
1- waxes
2- Sterol esters :

3. Biochemistry
٣
Contain free sterols , the sterols : are esterifies to fatty acids and
called as sterol esters .
Ex,
Cholestrol : from animals Beta sitosterol : from plants
3- Acylglycerol : glycerol as monoacylglycerols (MG) , diacylglycerols
(DG), triacylglycerols (TG) , they are important in absorption and
digestion of fats .
What Is the Difference between Fats and Oils?
Answer
- fats are solid at room at room temperature .
- oils are liquid at room temperature.
- Fats are usually derived from animals
- oils are from plants.
Formation of triglycerides
 When glycerol reacts with three fatty acids, it forms triglycerides
+ 3RCOOH
CH2OH
CHOH
CH2OH
Glycerol
CH2OCOR
CHOCOR
CH2OCOR

4. Biochemistry
٤
‫اﻟﺘﺴﻤﯿﺔ‬:-
1-  or - + mono, tri,.. + in ‫ووﺿﻊ‬ IC ‫ﺣﺬف‬ .
٢-‫ﺟﻠﯿﺴﺮول‬ ‫أﺳﯿﻞ‬ ‫ﺛﻼﺛﻰ‬‫ﻣﺨﺘﻠﻂ‬١-‫ووﺿﻊ‬ ‫ﯾﻚ‬ ‫ﺣﺬف‬ ‫ﻣﻊ‬ ‫اﻟﺤﻤﺾ‬ ‫أﺳﻢ‬
‫ول‬–Sn-‫ﺟﻠﯿﺴﺮول‬
H2C1
C
2
H
3
HO
H2C
OH
OH
L-propane-1,2,3-triol



Monoglycerides
If glycerol react with one
molecule of fatty acid
Diglycerides.
If glycerol react with two
molecules of fatty acid
Triglycerides
If glycerol react with 3 molecules of
fatty acid
CH2OCOR1
CHOH
CH2OH
CH2OCOR1
CHOCOR2
CH2OH
CH2OCOR
CHOCOR
CH2OCOR

5. Biochemistry
٥
saponifacation١-‫اﻟﺒﺴﯿﻄﺔ‬ ‫اﻟﻠﺒﯿﺪات‬:‫دھﻨﯿﺔ‬ ‫أﺣﻤﺎض‬+‫ﻛﺤﻮل‬:
‫اﻟﻠﯿﺒﯿﺪ‬ ‫ﺑﺎدﺋﺎت‬Lipids precursors‫أﻣﺜﻠﺘﮭﺎ‬:‫واﻟﺸﻤﻮع‬ ‫واﻟﺪھﻦ‬ ‫اﻟﺰﯾﻮت‬
٢-‫اﻟﻤﺮﻛﺒﺔ‬ ‫اﻟﻠﺒﯿﺪات‬:‫أﻣﺜﻠﺘﮭﺎ‬:‫دھﻨﯿﺔ‬ ‫أﺣﻤﺎض‬+‫ﻛﺤﻮل‬+‫أﺧﺮى‬ ‫ﻣﻮاد‬
)‫ﻓﻮﺳﻔﺎﺗﯿﺔ‬ ‫دھﻨﯿﺎت‬–‫ﺳﺮﺑﻮرﺳﯿﺪ‬=‫ﺟﻠﯿﺴﻮﻟﯿﺒﯿﺪ‬=Lipo protein.(
‫ﻗﺎﺑﻠ‬ ‫ﻏﯿﺮ‬‫ﺔ‬‫ﻟﻠﺘﺼﺒﻦ‬١-‫اﻟﻤﺸﺘﻘﺔ‬ ‫اﻟﻠﺒﯿﺪات‬)‫اﻟﻤﺸﺘﻘﺔ‬ ‫اﻟﺪھﻨﯿﺎت‬: (‫اﻟﻤﻮ‬ ‫ﻣﺜﻞ‬‫ﻣﻦ‬ ‫وأﻧﻮاﻋﮭﺎ‬ ‫اﻟﻤﻠﻮﻧﺔ‬ ‫اد‬
‫اﻷﺳﺘﯿﺮوﻻت‬.
emulsification of lipids:-
(chemistry) The process of dispersing one liquid in a second immiscible liquid; the largest group of
emulsifying agents are soaps, detergents, and other compounds, whose basic structure is a paraffin
chain terminating in a polar group.
---------------------------------------------------------------------------------------------------------------

6. Biochemistry
٦
Compound lipids
- Lipids: phospholipids ‫اﻟﻠﯾوﻓوﺳﻔوﻟﯾﺑﯾدات‬
Phosphatidic acids (PAs) + Hydroxyl compound .
‫اﻟﻔﻮﺳﻔﺎﺗﯿﺔ‬ ‫اﻷﺣﻤﺎض‬:-
‫اﻟﺤﯿﻮى‬ ‫اﻟﺘﺨﻠﯿﻖ‬ ‫ﻓﻰ‬ ‫دور‬ ‫ﻟﮭﺎ‬..
P
O
OH
OH
CH2OCOR
CHOCOR1
CH2O
Polar compound by H2PO3 group .
- 1- Phosphatidylcholine = lecithin = PC .
Phosphatidylcholines (PC) are a class of phospholipids that
ncorporate choline as a headgroup. They are a major component of biological
membranes and can be easily obtained from a variety of readily available
sources, such as egg yolk .
FUNCTION :- It is thought to be transported between membranes within the
cell by phosphatidylcholine transfer protein (PCTP).
P
O
O
OH
CH2OCOR
CHOCOR1
CH2O (CH2)2 N
CH3
CH3
CH3
Lecithin=phosphatidyl choline
P
O
O
OH
CH2OCOR
CHOH
CH2O (CH2)2 N
CH3
CH3
CH3
Lysolecithin
 By phospholipase D (PLD), via the hydrolysis of the P-O bond
of phosphatidylcholine (PC) to produce PA and choline.

7. Biochemistry
٧
2- phosphatidyl ethanolamine = PE
‫اﻟﻜﯿﻔﺎﻟﯿﻨﺎت‬)‫أﻣﯿﻦ‬ ‫إﯾﺜﺎﻧﻮل‬ ‫ﻓﻮﺳﻔﺎﺗﯿﺪﯾﻞ‬.(
P
O
O
OH
CH2OCOR
CHOCOR1
CH2O (CH2)2 NH2
3- Phosphotidylserin = PS.
‫ﺳﯿﺮﯾﻦ‬ ‫ﻓﻮﺳﻔﺎﺗﯿﺪﯾﻞ‬)‫اﻟﻤﺦ‬ ‫ﻓﻰ‬.(
P
O
O
OH
CH2OCOR
CHOCOR1
CH2O
H2
C
H
C NH2
COOH
Essential component of phospholipid bilayer of cell membranes
‫اﻟﺨﻼﯾﺎ‬ ‫أﻏﺸﯿﺔ‬ ‫ﻓﺴﻔﻮﻟﯿﺒﯿﺪ‬ ‫ﺛﻨﺎﺋﯿﺔ‬ ‫طﺒﻘﺔ‬ ‫ﻣﻦ‬ ‫أﺳﺎﺳﻲ‬ ‫ﻋﻨﺼﺮ‬
4- Phosphotidylinositol = PI.
‫اﻷﻧﯿﻮﺳﯿﺘﻮل‬ ‫ﻓﻮﺳﻔﺎﺗﯿﺪﯾﻞ‬)‫وﻧﺒﺎﺗﻰ‬ ‫ﺣﯿﻮاﻧﻰ‬: (-
Essential component of phospholipid bilayer of cell membranes
‫اﻟﺨﻼﯾﺎ‬ ‫أﻏﺸﯿﺔ‬ ‫ﻓﺴﻔﻮﻟﯿﺒﯿﺪ‬ ‫ﺛﻨﺎﺋﯿﺔ‬ ‫طﺒﻘﺔ‬ ‫ﻣﻦ‬ ‫أﺳﺎﺳﻲ‬ ‫ﻋﻨﺼﺮ‬

8. Biochemistry
٨
Phospholipase= enzymatic hydrolysis
A phospholipase is an enzyme that hydrolyzes phospholipids[1]
into fatty acids and
other lipophilic substances. There are four major classes, termed A, B, C and D, distinguished by
the type of reaction which they catalyze:
 Phospholipase A
 Phospholipase A1 - cleaves the SN-1 acyl chain.
 Phospholipase A2 - cleaves the SN-2 acyl chain,
 Phospholipase B - cleaves both SN-1 and SN-2 acyl chains; =lysophospholipase.
 Phospholipase C - cleaves before the phosphate, releasing diacylglycerol and a
 Phospholipase D - cleaves after the phosphate, releasing phosphatidic acid and an
alcohol.
Types C and D are considered phosphodiesterases.
Example :-

9. Biochemistry
٩
Hydrolysis
Complete hydrolysis of phospholipids is easily affected by
acidic media and with alkali the acyl groups are split .
PC -----strong acid hydrolysis  choline + glycerophosphoric acid + 2 FAS.
PC -----mild alkali hydrolysis  Fas from 1 and 2 positions + glcerophosphatidyl choline (GPC) .
Sphingophospholipids
All contain
sphingosin
CH3(CH2)12 CH CH CH
OH
CH
NH2
CH2OH
Shingo lipids contain faty acids but none contain glycerol
Example :-
ceramide sphingomeilin
Sphingosin bond to fatty acid through an
amide linkage .
Sphingosin bond to fatty acid through an
amide linkage and other linkage with
phospholipid.
Function :-
Found at nervous system , surrounding the fastest conducting nerve fibers .
Glyco lipids
Lipids containing carbohydrate .
2 classes :-
1- Cerebrosides : consist of hexose sugar , they are formed
of the myelin of the nerve axons‫اﻟﻌﺻﺑﯾﺔ‬ ‫اﻟﻣﺣﺎور‬
2- Gangliosides :carbohydrate protion is very complex , they
gray matter of brain is rich in gangliosides.
‫ﻏﻧﯾﺔ‬ ‫اﻟدﻣﺎغ‬ ‫ﻣن‬ ‫اﻟرﻣﺎدﯾﺔ‬ ‫اﻟﻣﺎدة‬ ‫ﻧﮭم‬gangliosides
derived lipids
very complex as cholesterol

10. Biochemistry
١٠
trans - fatty acids and (lDl) raises plasma concentration of
lipoprotein and low risk of heart attack but cis- fatty acids and
(HDl) decrease plasma concentration of lipoprotein and low risk
of heart attack
Fatty acid
1- The main costituent of many lipids .
2- Have asingle carboxyl group (polar) and long
hydrocarbon chain (non-polar) .
Nomenclature
Not, ……
Geometric Isomerism
C C
H H
CH3
Trans-Cis-
CH3(CH2)4
C C
H
H
CH3
CH3(CH2)4
C C
H CH3
CH3
CH3(CH2)4
No,Cis-
No,Trans-

11. Biochemistry
١١
Oleic acid C 18 C-9 ------(18:1c Δ9) or (18:1t Δ9) ώ9. ‫اﻟﺰﯾﺘﻮن‬ ‫زﯾﺖ‬ ‫ﻓﻲ‬
Ex: CH3(CH2)7CH=CH-(CH2)7COOH.
CH3(CH2)7
H H
(CH2)7COOH
Cis-
CH3(CH2)7
H
H
(CH2)7COOHTrans-
Physical proparites :- m.P or B.P
1- Unsaturated faty acid < saturated faty acid .
2- Cis – form ( curved structure) < trans – form (linear structure ) .
3- Longer chain > short chain .
Hydrogenation of unsaturated fatty acid :H2/ Ni
---------------------------
Synthesis of Vitamin D in the Skin by Sunlight
Cholesterol--- 7-Dehydrocholesterol Vitamin D
StructureAcid Name
CH3(CH2)2COOHButyric
CH3(CH2)10COOHLauric

12. Biochemistry
١٢
Essential fatty acid
- Essential fatty acids, or EFAs, are fatty acids that humans and other
animals must ingest because the body requires them for good health
but cannot synthesize them
- "essential fatty acid" refers to fatty acids required for biological
processes .
Examples:
The essential fatty acids start with the short chain polyunsaturated fatty acids (SC-
PUFA):
 ω-3 fatty acids:
 α-Linolenic acid or ALA (18:3n-3)
 ω-6 fatty acids:
 Linoleic acid or LA (18:2n-6)
These two fatty acids cannot be synthesized by humans because humans lack
the desaturase enzymes required for their production.
They form the starting point for the creation of longer and more desaturated fatty acids,
which are also referred to as long-chain polyunsaturated fatty acids (LC-PUFA):
 ω-3 fatty acids:
 eicosapentaenoic acid or EPA (20:5n-3)
 docosahexaenoic acid or DHA (22:6n-3)
 ω-6 fatty acids:
 gamma-linolenic acid or GLA (18:3n-6)
 dihomo-gamma-linolenic acid or DGLA (20:3n-6)
 arachidonic acid or AA (20:4n-6)
ω-9 fatty acids are not essential in humans because they can be synthesized from
carbohydrates or other fatty acids
fuction of …..
- Arachidonic acid (AA, sometimes ARA)-------- present in the phospholipids
of membranes of the body's cells, and is abundant in the brain, muscles, and liver.
- Hormones are chemical messengers secreted by cell or gland. These messengers
are sent out from one part of the body to affect cells in other parts of the body
- Chylomicrons transport exogenous lipids to liver, adipose, cardiac, and skeletal
muscle tissue, where their triglyceride components are unloaded by the activity of
lipoprotein lipase. As a consequence, chylomicron remnants are left over and are
taken up by the liver.