M1. Lipids Flashcards
- organic compound [carbon containing substances] found in living organisms
- insoluble (or only sparingly soluble) in water
- soluble in non-polar organic solvents
- lipids of plants in origin.
LIPIDS
OILS
True or False?
Lipids can be defined through their structural features.
False.
- Lipids do not have a common structural features that serves as the basis for defining such compounds.
- Lipids cannot be characterized in terms of structure due to their structural diversity.
Classification basis for Lipids?
Their SOLUBILITY. NOT ON FUNCTIONAL GROUPS.
Lipids are ____ in WATER.
INSOLUBLE/ SPARINGLY SOLUBLE
Lipids are ____ in NON-POLAR ORGANIC SOLVENTS.
SOLUBLE
**
Examples of Organic Solvents that can solubilize Lipids:
- Ether
- Alcohol
- Benzene
- Toluene
- Chloroform
Five Categories of Lipids:
EME, nandiyan sa bag CP mo, hindi na nakaw.
- Energy-storage of Lipids
- Membrane Lipids
- Emulsification Lipids
- Chemical messenger Lipids
- Protective-Coating Lipids
Energy-storage lipids:
- stored from of energy?
TRIACYLGLYCEROLS
Membrane Lipids:
- structural components?
- PHOSPHOLIPIDS
- SPHINGOGLYCOLIPIDS
- CHOLESTEROL
Emulsification Lipids:
- they are crucial in lipid breakdown and helps in the intestinal absorption
BILE ACIDS
Chemical Messenger Lipids (Cell-to-Cell Communication):
- important in dietary constituents of fat-soluble vitamins such as Vitamin A, D, E, K
- STEROID HORMONE
- EICOSANOIDS
Protective-Coating Lipids:
- acts as a thermal-insulator that can be found in the subcutaneous tissues and around the certain organs
Biological Waxes
- exhibits structural diversity.
- Some are esters, some are amides, and some are alcohols (acyclic and cyclic) and some are polycyclic
Lipids
- building block/s of Lipids.
- simplest or basic unit to constitute complex types of lipids
Fatty Acids
- they are Carboxylic acids with linear (unbranched) carbon chain
- naturally occurring monocarboxylic acids
Fatty Acids
General Formula for Lipids?
RCOOH
- represents the long aliphatic chain of carbon atoms
- unique to fatty acids
- basis for the fatty acids identification
R group
Even numbers of Carbon atoms:
- Long-chain fatty acids
- Medium-chain fatty acids
- Short-chain fatty acids
The carbon chain of the fatty acids may or may not contain carbon to carbon double bonds.
Long-chain fatty acids’ number of Carbon atoms?
12-26 Carbons
Medium-chain fatty acids’ number of Carbon atoms?
8-10 Carbons
Short-chain fatty acids’ number of Carbon atoms?
4-6 Carbons
2 types of FA?
- Saturated FA
- Unsaturated FA
- all C-C bonds are single bonds
- numbering starts from the end of -COOH group
SATURATED FATTY ACIDS
C-C bonds are double bonds
UNSATURATED FATTY ACIDS
Two subdivisions of Unsaturated FAs:
- Monounsaturated FA
- Polyunsaturated FA [PUFAs]
- one C=C bond present
- different ways of depicting the structure
MONOUNSATURATED
- 2 or more C=C bonds present
- up to six double bonds are present in fatty acids
POLYUNSATURATED
Two types of unsaturated fatty acids:
- Omega-3 fatty acids: 3 double bonds
- Omega-6 fatty acids: 6 double bonds
- Essential Fatty Acids
- Must be part of diet
- examples are Omega-3 FA & Omega-6 FA
OMEGA ACIDS
Types of nutritionally important omega acids:
- Linolenic Acid: omega-3
- Linoleic Acid: omega-6
they have a 7:1 ratio.
1 for w3
7 for w6
Linoleic Acid Deficiency:
SILCH
- skin redness
- infections & dehydration
- liver abnormalities
- children needs it most
- human milk has more linoleic acid than cow’s milk
Water Solubility of FAs:
- sparingly soluble in water because of CARBOXYLIC ACID POLAR GROUP
- insoluble in water
- short-chain FA
- long-chain FA
@ room temperature:
- FAs w/ 10 carbons or less are ____ in nature. OILS.
- FAs w/ more than 10 carbons are ____ in nature. FATS.
- liquid
- solid
Melting poing of Lipids depends on?
- number/length of carbon chains
- degree of unsaturation
more FAs carbon chains = insoluble in water
Melting Point:
Carbon chain: increases
Melting point: ____
increases
Melting Point:
More double bonds: ____
less efficient/ more liquid
Melting Point:
Low melting point: ____ @ room temp.
liquid
Space-Filling Molecules
increase number of bends in FAs chains: ____
increase number of double bonds
- Less packing occurs
- Melting point is lower
- Liquid at room temperature
- concentrated primarily in special cells (adipocytes)
- energy-storage material of lipids.
TRIACYLGLYCEROLS
TWO TYPES OF TRIACYLGLYCEROLS:
- Simple Triacylglycerols
- Mixed Triacylglycerols
Three identical fatty acids are
esterified
Simple Triacylglycerols
triester formed from the esterification of glycerol w/ more than one kind of fatty acid
Mixed Triacylglycerols
Triacylglycerols are linked by?
Ester Linkages/ Bonds
formed from the Carboxyl group of fatty acid and OH group from the alcohol
Esters/ Ester bonds
FATS & OILS
PHYSICAL STATE:
1. saturated + solid @ room temp.
2. unsaturated + liquid @ room temp.
- fats
- oils
FATS & OILS
- animal source + tasteless
- plants + fish oils
- colorless + odorless
- fats
- oils
- pure fats & oils
used for dietary considerations or TAG/ATG
fats
recommended amounts of total fat intake in calories:
1. monounsaturated fats
2. polyunsaturated fats
3. saturated fats
- 15%
- 10%
- <10%
are considered “bad fats”
saturated fats
trans-monounsaturated fats
are considered “good fats”
monounsaturated fats
- can be both “good fats” and “bad fats”
- Omega 3 and 6 are important polyunsaturated “good fats”
polyunsaturated fats
- Fatty acids obtained from dietary sources
- not synthesized within the body
ESSENTIAL FATTY ACIDS
- have a strong protective effect against coronary heart disease
- low saturated fatty acids
- have antioxidant vitamins and minerals
- have plant fiber protein
Nuts
[eatings nuts]
Chemical Reactions of Triacylglycerols:
- Partial Hydrolysis
- Saponification
- Hydrogenation
- Oxidation
- Chemical Properties due to two functional groups: esters and alkenes
- Breaking of 1-2 ester bonds to give rise to mono- or diacylglycerol and fatty acid(s)
- Carried out by enzymes produced by the pancreas
1) what is the pancreatic enzyme mentioned above?
2) 2 attached FA directly against the glycerol + 1 free FA
3) 1 attached FA + 2 free FA
PARTIAL HYDROLYSIS
1) PANCREATIC LIPASE
2) Diglyceride
3) Monoglyceride
- HYDROLYSIS in basic solution
- treated w/ STRONG ALKALI SOLUTION
- Produce salt of fatty acid and glycerol
the 2 strong alkali solutions:
SAPONIFICATION
- NaOH
- KOH
Addition of hydrogen across double (=) bond - increases degree of saturation
catalysts used on this chemical reaction?
HYDROGENATION
1) Fe
2) Cu
3) Co
- Double bonds in triacylglycerols are subject to oxidation with oxygen in air (an oxidizing agent )
- Leads to C=C breakage
oxidation of alkenes may result into two short chain molecules. They are?
OXIDATION
- aldehydes
- carboxylic acid
- these two have objectionable odors or are rancid due to oxidation.
- To avoid this unwanted oxidation process antioxidants are added as preservatives.
- They are good antioxidant preservatives.
Vitamin C and E
this lipid contains:
- one or more fatty acids
- phosphate group
- platform molecule (glycerol or sphingosine)
- alcohol
- fatty acids and phosphate group are attached to the glycerol.
- alcohol is attached to the phosphate group.
Phospholipids/Glycerophospholipids
alcohols that may be attached to the phosphate group are:
- choline/ phosphatidylcholines
- ethanolamine/ phosphatidylethanolamines
- serine/ phosphatidylserines
they are called CEPHALINS
triacylglycerols & glycerophospholipids have different:
- biochemical functions
- polarity
- can be seen in the brain and lungs.
- have function in blood coagulation.
- are soluble in methanol & ethanol.
- function as components of cell membranes.
- polar
Glycerophospholipids
- energy storage molecules
- non-polar
Triacylglycerols
- 18-carbon monounsaturated amino-dialcohol sphingosine.
- 1 FA + 1 phosphate group attached to Sphingosine.
- Alcohol attached to phosphate group.
- Saponifiable lipids
- the alcohol esterified to the phosphate group is choline are called
- found at the gray-matter
SPINGOPHOSPHOLIPIDS
sphingomyelins
- found in all cell membranes
- important structural components of the myelin sheath of neurons
SPHINGOMYELINS
Contains both a fatty acid and carbohydrate
Sphingoglycolipids
- Simple sphingoglycolipids
- found in the white matter
- contains a single monosaccharide unit - either glucose or galactose
- occur primarily in brain (7% of dry mass)
Cerebrosides
- Complex sphingoglycolipids
- branched chain of up to seven monosaccharide residues
- found in the gray matter & in the myelin sheath
Gangliosides
- third major type of membrane lipid
- Lipids: Fused Rings
- C27 steroid molecule
- Important in human cell membranes, nerve tissue and brain tissue
is a lipid whose structure is based on a fused ring system of three 6 carbon rings and one 5 carbon ring.
CHOLESTEROL
steroid
- synthesized in the liver at least 1 g everyday.
- synthesis decrease if it is ingested but reduction is not sufficient.
- Leads to cardiovascular disease.
CHOLESTEROL
Animal Food: Lot of cholesterol
Plant Food: No cholesterol
- surrounded by plasma membranes
- Separates aqueous interior of a cell from the aqueous environment
- 80% of plasma membrane is lipid material
membranes are lipid bilayer made up of…
CELLS
phospholipids
- Nonpolar tails: middle
- Polar heads: surface
liquid like structure due to unsaturation in lipid tails
Membranes
Plasma Membrane components:
- cholesterol
- protein
- helps regulate membrane fluidity
- make it rigid
- acts a membrane plasticizer
- fused ring system does nor allow rotation of fatty acid tails in the vicinity
- Fits between fatty acid chains of the lipid bilayer
CHOLESTEROL
- for moving substances (nutrients & electrolytes)
- Receptors for hormones and neurotransmitters
- Act as markers (for recognition of different cells)
PROTEINS
Lipids with proteins are?
non-polar lipids
- protein part of the lipoprotein
- held together by non-covalent force
APOPROTEIN/
APOLIPOPROTEIN
- tri- or dihydroxy cholesterol derivatives
- carbon 17 side chain of cholesterol has been oxidized to a carboxylic acid
-
oxidized acid side chain is bonded to an amino acid
(either glycine or taurine) through an amide linkage
BILE ACIDS
- secreted by the liver
- stored in the gallbladder
- released into the small intestine
hormone that signals the bile acids to release
BILE ACIDS
cholecystokinin
primary bile acids and end products of cholesterol catabolism
cholic acid
chenodeoxycholic acid
- produced by a ductless gland [endocrine gland]
- a messenger function.
- means of communication between various tissues
- are lipids
HORMONES
lipids that play the role of “chemical messengers”
- cholesterol derivatives
- arachidonic acid derivatives
- steroid hormones
- eicanosoids
two major classes of steroid hormones:
- control reproduction and secondary sex characteristics
- control numerous biochemical processes in the body.
- sex hormones
- adrenocorticoid hormones
three major groups of sex hormones:
- female sex hormones
- male sex hormones
- pregnancy hormones
- Estrogens
- Androgens
- Progestins
- produced by the adrenal glands
small organs located on top of each kidney
ADRENOCORTICOID HORMONES
adrenal glands/ suprarenal gland
Two types of adrenocorticoid hormones:
- mineralocorticoids/ G zone
- glucocorticouds/ F zone
control the balance of Na and K ions in cells
Mineralocorticoids
control glucose metabolism and counteract inflammation
Glucocorticoids
- local hormone
- arachidonic derivates
- 20 carbon atoms:4 doubles bonds
- hormone-like molecules
- very short life
Eicosanoids
Physiological effects of eicosanoids:
- inflammatory responses
- pain & fever production
- regulates BP
- induction of blood clotting
- controL reproductive functions (induction of labor)
- regulation of sleep/ wake cycle (itigil mo na, Eicosanoids sa katawan ko T^TXD)
THREE PRINCIPLE TYPES of Eicosanoids:
carbohydrate: prostonoic
- Prostaglandins
- Thromboxanes
- Leukotriens
C20-fatty-acids
- cyclopentaine ring + oxygen-containing functional groups
- prevented by aspirin
- C20-fatty acid derivatives
Prostoglandins
physiological effects of prostaglandins:
- increases body temp. [fever]
- secretion of gastric juices
- secretion of protective mucus layer
- relaxation & contraction of smooth muscles
- directs water & electrolyte balance
- intensifies pain
- enhances inflammation responses
- cyclic ether + oxygen-containing functional groups
- C20-fatty acid derivatives
- promote platelet aggregation
Thromboxanes
- conjugated doubles bonds + hydroxy groups
- C20-fatty acids
- promote inflammatory & hypersensitivity (allergy) responses
Leukotrienes
monoester of a long-chain fatty acid and a long-chain alcohol.
biological wax
- Generally are saturated fatty acids
- Contain 14 to 36 carbon atoms.
fatty acids found in biological waxes
- May be saturated or unsaturated
- May contain 16 to 30 carbon atoms
alcohols found in biological waxes
Biological waxes are water-insoluble and water-repellent because of ____.
long nonpolar hydrocarbon chains
Function of biological waxes
- protection
- water repellency
- feather water-repellent
- minimizes loss of body heat
- plants coat
- prevent excessive evaporation
- protect agains parasite attack