Lipids 1 Flashcards
Classification
Simple»
Triglycerides» oils/fats
Waxes
Conjugated simple+other group
Derived hydrolysis or associated
Definition of lipids
Formula
Organic compounds that are related to fatty acid esters
Alcohol+fatty acid»(esterification) triglyceride
Dietary importance
High energy 9kcal
Fat soluble compounds
Essential fatty acids
In plasma, adipose,membranes
Why are triglycerides neutral?
Due to loss of OH (-ve charge) during esterification
How lipids move in blood
Lipoproteins
Where are free fatty acids
In plasma
Natural fatty acids are..
Monocarboxylic(even no.of C)
Formula
Ch3-(ch2)n-cooh
N = total C-2
Numbering fatty acids
C numbering»from COOH
Greek»first C after COOH (alpha-beta)
Omega»from terminal methyl group
Classification acc to length+ examples
Short [6>]»_space; butyric
Medium[6-10]»_space;caproic
Long [12-18]»palmatic/stearic
Very long[>20]»arachidonic/lighoceric
Palmatic and stearic are…
Saturated
16 C
18C
Archidonic and lignoceric are..
20C
24C
Why are unsaturated fatty acids liquid
Due to the presence of cis bonds which form kinks
Classification acc to double bond
Saturated>most common, increased intake, increased cholesterol levels
Unsaturated>trans, cis
Trans
What
Hazards
Formed during hydrogenation of vegetable oils
1.compete with essential fatty acids, causing deficiency
2.hyoercholesterolemia + atherosclerosis
Cis
Monoenoic> 1 double bond
Palmitic w7:16:1
Oleic w9:18:1
Nervonic 19:24:1
Polyenoic (PUFA)> more than 1 double bond
W3» a linolenic 18 c/timnodonic 20c
W6» linolei 18c /archidonic 20 c
Importance of PUFA
Eicosanoids, lipoxins and prostaglandins
Phospholipid formation
Classification acc to nutritional value
Essential (not synthesised in body)» a linoleic/linoleic
non essential»_space;formed from carbs
Is archidonic essential?
No cuz its synthesised except in the absence of linoleic(which it is synthesised from) it becomes essential .
Fatty acids deficiency
Dermatitis in infants
Fatty liver
Growth retardation
Defective sperms
Brain and retina defects
Fatty acids reactions with carboxylic group
Esterification (glycerol+ 3 fatty acids> TAG+ H2O)
Salt/soap(fatty acid+ NaOH> RCOONa + H2O)
Double Reduction(RCOOH>RCHO>RCH2OH)Fatty alcohol
Reactions with double bonds
Oxygen»USFA > peroxide
Hydrogen» (oleic +2 h> stearic)(linoleic+ 4h >stearic)
Dangers of peeoxides
Destructs lipoproteins and cell membranes by splitting fatty acid chains.
Eicosanoids
Hormone like molecules
From PUFA with 20C
No. Under name= no. Of double bonds
Classification of eicosanoids
Cyclic(prostanoids)» prostaglandins/prostacyclins/thromboxanes
Acyclic»leukotriens/ lipoxins
Why are eicosanoids not hormones
Act locally
Produced in small amounts all over the body
Not stored
Short half lives
Prostaglandins importance
Promote inflammation
Reproduction process(ovulation+ uterine contraction)
Inhibits gastric secretion
PGE2>vasodilation
PGF2a>vasoconstriction
Prostacylins
Vascular epithelium
Vasodilation
Inhibit platelet aggregation
Thrombaxanes by platelets
Vasoconstriction
Promote platelets aggregation (thrombus)
Leukotriens by leukocytes during anaphylaxis
Respiratory distress
Broncho constriction
Low blood pressure
Shock
Inhibited by drugs like singulare