SIMPLE and COMPLEX lipids Flashcards
Simple Lipids
➡️ Waxes
•esters formed from long-chain fatty acids and long-chain alcohols
most natural waxes are: mixtures of such ______
esters.
Plant waxes
•protection from dehydration and invasion
Carnauba wax
•used extensively in floor waxes, automobile waxes, and furniture polish; largely myricyl cerotate
Animals
•protective coatings, keeping the surface of feathers, skin, and hair pliable and water repellent.
Myricyl cerotate -> (found in _____ wax)
carnauba wax
Complex lipids
➡️ phospholipids and glycolipids
Membrane lipids
•found in cell
•make up 80% of membrane mass
•boundary
3 types:
- Phospholipids
- Sphingoglyco- lipids
- Cholesterol
Phospholipids
• contain an alcohol, two fatty acids, and a phosphate group
2 types of Phospholipids
- Glycerophospholipids
2.Sphingolipids
Glycerophospholipids
•the alcohol is glycerol
Sphingolipids
•the alcohol is sphingosine
Most abundant
Phospholipids
components of Phospholipids:
- One or more fa
- PO4
- A platform molecule ➡️ fa and PO4 are attached; 3C glycerol (Glycerophospholipid) or a complex C18 aminodialcohol/ sphingosine (sphingophospholipid)
- Alcohol- attached to the PO4 group
Phospholipids have
________ head and ______ tail
Hydrophilic head and Hydrophobic tails
Hydrophilic head:
•chlorine
•phosphate
•glycerol
Hydrophobic tails:
•fatty acids
Glycerophospholipids
•2fa + PO4 esterified to a glycerol and an alcohol esterified to a PO4 group
•Bond: 4Ester linkage
Phosphoglyceride
•phosphatidylethanolamines or cephalins
•phosphatidylcholines or lecithins
phosphatidylethanolamines or cephalins
➡️ found in brain tissue and nerves and also have a role in blood clotting.
phosphatidylcholines or lecithins
➡️ important constituents of nerve and brain tissue.
ex: egg yolk are especially rich in lecithins
•commercial-grade lecithins isolated from soybeans are widely used in foods as emulsifying agents (milk-casein; mayo-egg yolk)
Due to ester linkage, it undergoes both _______ and ______reactions similar to Triacylglycerols.
saponification and hydrolysis
Phosphoric acid
•parent source for the (-) charged PO4 group
OH ➡️ 1 of 3 amino alcohol
a. chlorine
b. ethanolamine
c. serine
Phosphatidylcholines, phosphatidylethanolamine, phosphatidylserine
AA
characteristics:
- Component of cell membranes
- Polar (due to their structure)
- Amphipathic
ex: phosphatidylcholines (aka lecithin) w/ stearic and oleic acid); polar head and nonpolar tail
Phosphatidylcholines
•waxy solids
•forms colloidal suspension in water
•source; eggyolk and soybeans
•prevalent in cell membranes
•made by the liver although supplements are available
•used as emulsifiers (ex. mayonnaise, ice cream, custard)
Cephalin
•phosphatidylethanolamine and phosphoaridylserine
•found in the ehe art and liver tissue
•brain- high concentrations
• important in blood clotting
Sphingophospholipids
•sphingomyelin - simplest Sphingolipid; important in nerve cells.
•contains a :
➡️ fatty acid
➡️ phosphoric acid
➡️ sphingosine;
➡️choline
Sphingophospholipid also undergo ______reaction.
saponification
Amide linkage behave as ________ in the reaction.
ester linkage
Cerebrosides
•composed of:
➡️ sphingosine
➡️ fatty acid
➡️ galactose or glucose
•resemble sphingomyeline but have a sugar unit in a place of the choline phosphate group.
•important constituents of the membranes of nerve and brains cells
Gangliosides
•branched chain of up to 6 monosaccharides residues
•gray matter of the brain and in myelins sheath
•more complex
•branched chain of three to eight monosaccharides and/or substituted sugars.
_____ varieties of Gangliosides due to sugar units.
130 varieties
•cell-to-cell recognition and communication processes
•most prevalent in the outer membranes of nerve cells
Gangliosides
Cerebrosides and Gangliosides contain sugar groups: classifies as _______
Glycolipids
Steroids
Nonsaponifiable
• bile salts, cholesterol, and related compounds, and certain hormones (such as cortisone and the sex hormones)
Steroids occur in ____, _____,_____, and ____ but not in bacteria.
plants, animals, yeasts, and molds
characteristic structural components of Steroid:
• 4 fused rings
Cholesterol
•the most abundant steroid in the human body (240g is a typical amount)
Excess cholesterol
factor in atherosclerosis and heart disease
about _________ cholesterol is interspersed in the lipid bolster of cell membranes
half of the body’s
much of the rest of the cholesterol is converted to _______ acid ➡️ used in the formation of ____ salts.
chronic acid; bile salts
Cholesterol is a precursor in the synthesis of ____ hormones, ____ hormones, and vitamin ___.
sex hormones, adrenal hormones, and vitamin D .
Cholesterol in the gallbladder precipitates in the form of ______.
gallstones
Greek “chole” , meaning ______;
and “stereos”, meaning _______
chole ➡️ bile
stereos ➡️ solid
Lipoproteins
•carriers of cholesterol
•transporter of fats
•contain a core hydrophobic lipid molecules surrounded by a shell of hydrophilic molecules sya h as proteins and phospholipids
4 kinds of Lipoproteins:
- High-density lipoprotein (HDL)
- Low-density lipoprotein (LDL)
- Very-low density lipoprotein (VLDL)
- Chylomicrons
“good cholesterol” consists of about 33% protein and about 30% cholesterol
High-density lipoprotein (HDL)
“bad cholesterol” contains only 25% protein but 50% cholesterol
Low-density lipoprotein (LDL)
mostly carries triglycerides( fats) synthesized by the liver
Very-low density lipoprotein (VLDL)
carries dietary lipids synthesized in the intestine
Chylomicrons
Transport of Cholesterol in LDL
•large VLDL particle
(core contains triglycerides and cholesteryl esters➡️ cholesteryl linoleate)
•surrounded by a polar coat of phospholipids and proteins
•VLDL is carried in the serum
coated pits
(Specific LDL-receptor molecules line the cell surface in certain concentrated areas)
