LIPIDS Flashcards
Occur frequently in nature
Defining/ determining parameter: Solubility
Marginally soluble in water: a portion is hydrophobic
Most are soluble in organic solvents
Nonpolar/ organic molecules: only react to nonpolar/ organic solvents
Provide major storing chemical energy in C-atoms in the body
Rich source of energy and has efficient way in storing excess calories
Lipids (Fats)
Thermal regulator: more fat/ adipocytes temperature is more regulated
Protection from mechanical shock
Mostly C and H bonds
Diverse structure
Plays a variety of biological roles; provide structure and furnish biochemical energy
Classification based on compounds:
Hydrophilic (H2O <3): polar head = soluble to water
Hydrophobic (H2O 3): nonpolar tails = insoluble in water
Marginally soluble
Fatty acids (simplest lipid class), triacylglycerols; triglycerides, sphingolipids, phosphoacylglycerols; phospholipids, glycolipids
Open-chain compounds with polar head groups and long nonpolar tails
Classification based on compounds:
Closed chain forming a ring
Steroids: cholesterol
Fused-ring compounds
Classification by Function: \_\_\_\_\_ lipids: Most abundant fatty acid Triacylglycerol (TAG): triglyceride Stored w/in adipocytes \_\_\_\_\_ lipids: 2nd most abundant Sphingoglycolipids, phospholipid, cholesterol
Energy storage
Membrane
Classification by Function: \_\_\_\_ lipids: emulsifies fat Bile acids: steroid acids \_\_\_\_ lipids Steroid hormones, eicosanoids \_\_\_\_ lipids Biological waxes (economic, beauty, pharmaceutical waxes)
Emulsification
Messenger
Protective-coating
Saponification Classification:
Converted into smaller molecules when hydrolysis occurs
Energy storage, membrane except cholesterol, and protective-coating lipids
Saponification lipids
Saponification Classification:
Cannot be broken into smaller units since they do not react/ interact with water = hydrolysis happen
Cholesterol, emulsification, messenger lipids
Non-saponification lipids
Classification by Structure
______: fats and waxes
______: Glycolipid, lipoproteins, phospholipids, sphingoglycolipids , aside from lipids it has other org molecule that is bonded in lipid structure
_____: cholesterol
_____: Prostaglandins, thromboxanes, leukotrienes
Simple lipids
Complex lipids
Steroids
Eicosanoids
Lipid Types:
simplest lipid class
Naturally occuring, monocarboxylic acid
Carboxyl group (COOH) at the polar end and a hydrocarbon chain (CH3) at the nonpolar tail
COOH: can react to water to form H-bonds
Amphipathic: both hydrophilic: polar and hydrophobic: nonpolar
Fatty acids
Nearly always contain an even number of carbon atoms and have a carbon chain that is unbranched
Building blocks of triglycerides and phospholipids
Sources of metabolic energy
Types of Fatty Acid: SFA: single bond Solid at room tempt Straight chain diff is number of atoms From animals
Saturated fatty acids (LMPSA)- Laway Mo Pre Sobrang Asim
Lauric, Myristic, Palmitic, Stearic, Arachidic
Types of Fatty Acid:
Dehydrogenated: reacts w/ H to form double bond
Once they undergo hydrogenated double bond can be broken down in the structure
Unsaturated fatty acids will be converted to saturated fatty acids via hydrogenation reaction
Once react w/ H, double bond will be broken down
Unsaturated fatty acids
Liquid at room tempt
Healthier fatty acids: because it is easier to be broken down by the body, from plants
Double bonds are easily broken down by the body
Types of Fatty Acid:
Most have Cis configuration: same side of double bond or atoms
Monounsaturated: single double bond
Polyunsaturated: 2 or more double bonds
Unsaturated fatty acids (POLLA)-
Palmitoleic, Oleic, Linoleic, Linolenic, Arachidonic
Characterization of FA via size of Carbon chain length: \_\_\_\_\_: >12 (12-26) Carbon atoms Insoluble to water \_\_\_\_\_: 8-10 C atoms \_\_\_\_\_: 2-6 C atoms
Long Chain
Medium chain
Short chain
Lipid Types:
3 fatty acid + 1 Glycerol = TAG
Animal fats (saturated, solid) and plant oils (unsaturated; polyunsaturated)
In relation to type of fatty acids found on the structure
Mostly liquid form and are from plants (corn, sunflower seeds)
Triester of glycerol and long chain of carboxylic acids called fatty acids
Triacylglycerols
triglycerides
Ester Bond/ esterification: link bet glycerol and fatty acids
Part of cell membrane, storage form of lipid
Energy storage lipids; most abundant
Neutral lipid; no charge = no polar hydrophilic group, water insoluble (very hydrophobic molecule)
Lipid Types:
Phosphate group + 2 Fatty Acid + 1 glycerol: structurally similar to triglyceride
3rd position in glycerol is responsible for bonding to phosphate group
Charged group; could interact w/ water bcs of phosphate group
Polar (phosphate, hydrophilic, outward) and nonpolar (hydrophobic, fatty acid) end
Amphipathic
One phosphoric acid can form ester bonds both to glycerol and to some alcohol
Ex: Phosphatidylinositol: beta-D-galactose and Phosphatidylcholine: choline is added
Phosphoacylglycerols
phospholipids, phosphoglyceride: ester bond
Most are derived from phosphatidic acid; component of the biological membrane
Phospholipid: abundant type of membrane lipid: 80% of mass of cell membrane
Two fatty acids are esterified to the glycerol molecules —> phosphatidic acid
Esterification: alcohol (glycerol) and acid (COOH) both react to form ester (R-O-R)
Lipid Types:
Lipid that is a monoester of long-chain carboxylic acids and long chain alcohols
Protective-coating lipid, for/ from both plants and animals
Saponifiable lipid
Saturated fatty acids: 14-36 carbon atoms
Alcohol: unsaturated or saturated: 16-30 C-atoms
Simple lipid
Waxes
Lipid Types:
amide bond
Do not contain glycerol but contain long-chain amino alcohol sphingosine
Abundant in nervous system
Ceramides: consist of one fatty acid linked to the amino group of sphingosine by an amide bond: sphingosine + 1 fatty acid
Sphingolipids
amide bond
Amino group of sphingosine can from an amide bond with a fatty acid carboxyl
Sphingosine —> ceramide
Sphingomyelin: Common constituents of plasma membranes
Sphingosine + 1 fatty acid + phosphocholine
Lipid Types:
glycosidic linkage, sugar containing lipid
Carbohydrate is bound to an alcohol group of a lipid by a glycosidic linkage
Glycolipids
primary alcohol of ceramide + sugar residue (single monosaccharide unit)
Aldohexose is usually present: galactose or glucose
Simplest glycolipid, sphingoglycolipids bcs of ceramide
7% dry mass of brain, also present in myelin sheath of nerves (CNS)
Cerebroside
glycolipids with complex sugars
Branched up to 7 monosaccharide residues in structure
Often found as markers on cell membranes and plays a large role in tissue and organ specificity
Also present in gray matter of brain and myelin sheath of nerves
Major lipid of cell membrane of brain and CNS
Gangliosides
Lipid Types:
Fused-ring containing 3 six membered rings and 1 five membered ring
Steroid nucleus = steroid fused ring
Ex: Cholesterol: unsaturated steroid alcohol
Hydrophilic group: OH (single, alcohol, outward, found on the C-3 of steroid nucleus)
Hydrophobic
Steroids
Steroid molecules w/ 27-C atoms
Most abundant steroid in the body
Esterified w/ 1 fatty acid, there is an ester bond found in the fatty acid molecules
Found in animals only = saturated fatty acids
Unsaturated only in the steroid nucleus
Precursors of 5 major classes of steroid hormones: androgens, estrogens, glucocorticoids, mineralocorticoids, and progestin
Precursor of other steroids and of Vitamin D3 however it is best known for its harmful effects
Manufacturing and repair of cell membrane
Synthesis of bile acids (liver) and Vit D3
Cholesterol
Important constituents of cell membranes
Decreases the mobility of hydrocarbon tails of phospholipids
Interferes with the closely packing of fatty acid tails in the crystalline state thus inhibits transition to the crystal state
Hydroxyl group on the aqueous side (outward) while the ring is towards the fatty acid chains of phospholipids.
The OH group of cholesterol forms a H bond with the polar phospholipid head groups.
Cholesterol
Responsible for fat being deposited in the plaque formation, found in the lining of blood vessels
Blocks the flow of the blood, can result to Atherosclerosis: plaque-formed in arteries
Waxy material which could form a plate-like crystal
Phospholipid membranes with high concentration of cholesterol have a fluidity intermediate between crystal and crystal state.
Lipid Soluble Vitamins:
retinol
Βeta carotene: in carrots
Unsaturated hydrocarbon: has double or triple bond
Precursor of vitamin A (retinol)
Responsible for red-orange pigment found in the plants
Vitamin A
Derivative of Vit A plays a crucial role in vision when it is bound to a protein (opsin)
Opsin: universal photoreceptor molecules, visual systems of animal kingdom
Light sensitive, found in retina
Lipid Soluble Vitamins:
Major role in regulation of calcium and phosphorus metabolism
Vitamin D3 (cholecalciferol) formed from cholesterol by the action of UV from the sun; increases absorption of calcium
Vitamin D
Further processed in the body to hydroxylated derivatives
Presence of Vit D3 leads to increase synthesis of a Ca2+ binding protein —> increases absorption of dietary calcium in the intestines —> increase calcium in circulation
Lipid Soluble Vitamins:
Biological active form: α-tocopherol; ready to be utilized in the body
Antioxidant: good reducing agent
Has 8 forms: 1st 4 is tocopherol, the other is tocotrienols
Vitamin E
It reacts with oxidizing agents before they can attack other biomolecules
Reacts with free radicals; fights w/ cancer (roar)
Peanuts, almonds, sunflower seeds
Lipid Soluble Vitamins:
phytonadione
Comes from “Koagulation” (German), it is an important factor in the blood-clotting process; hemostasis
Vitamin K
Secondary: clotting/ coagulation factors = I, fibrin clot; permanent
Vit K dependent clotting factors: II (prothrombin), VII, IX (Christmas factor), X
Requirement to modify prothrombin and other proteins involved in the clotting process
Lipid Types:
Messenger lipid; oxygenated C-20 fatty acid derivative
Polyunsaturated fatty acid: 4 double bonds
Metabolic precursor: arachidonic acid (20-C, 4 double bonds: 5,8,11,14)
Almost all cells produce eicosanoids, except RBCs
Eicosanoids
ODD MAN OUT: Function Physiological effects of eicosanoids: 1. Regulation of blood pressure 2. Production of pain and fever 3. Inflammatory response 4. Moisturization of organ surfaces 5. Induction of blood clotting 6. Control of reproductive functions 7. Regulation of sleep/wake cycle: Circadian rhythm
- Moisturization of organ surfaces
Types of Eicosanoids:
named after the prostate gland
Metabolic precursor is arachidonic acid
Found in dense tubular system of platelets
Cyclopentane ring + O2 containing functional group
Prostaglandins
Functions: Control of blood pressure Stimulation of smooth muscle contraction Induction of inflammation/ pain Raise body temperature Inhibit the secretion of gastric juices
Types of Eicosanoids:
from arachidonic acid
Found in leukocytes, has 3 conjugated double bonds and a Hydroxyl group (OH) in structure
Mostly for inflammation and hypersensitivity (allergy)
Leukotrienes
Functions:
Constriction of smooth muscle
Inflammatory properties
Maybe involved in rheumatoid arthritis (hypersensitivity)
Types of Eicosanoids:
Derivative of arachidonic acid
Contains cyclic ethers ring and O2 containing functional group as part of its structure
Thromboxane A2 is the most widely studied, is known to induce platelet aggregation (primary hemostasis, helps formation in the cloth) and smooth muscle contraction
Aspirin: blood thinner, react/ inhibits w/ thromboxane A2, so there would be no platelet aggregation, taken by people who experienced mild stroke or acute myocardial infarction
Thromboxane
