Lectures 11-12

fatty acids and triacylglycerols

What are the two lipids involved in energy storage?

sphingolipids and glycerophospholipids

What are the two lipids involved in cell membranes?

elcosanoids and steroids

What are the two lipids involved in endocrine signaling?

acetyl-CoA carboxylase and fatty acid synthase

What are the two enzymes involved in fatty acid synthesis?

acetyl-CoA

What is the main product at the end of fatty acid degradation?

fatty acids

a type of lipid that has a long hydrocarbon tail (the tail) and a terminal carboxyl group (the head)

4.8; this is below phsiological pH, so all fatty acids will be deprotonated at the carboxyl group

What is the pKa of a fatty acid? Why is it important to consider this?

just an example: Oleic acid (18:1) means this fatty acid has 18 carbons in total (including the head group) and 1 double bond (which indicates unsaturation)

How does nomenclature work with fatty acids and how many saturations / unsaturations they have?

animals

Are saturated fats more common in animals or plants?

plants

Are unsaturated fats more common in plants or animals?

“Please Order Large Appetizers; Grab Another Nacho”

-Palmitoleic acid

-Oleic acid

-Linoleic acid

-alpha linolenic acid

-gamma linolenic acid

-arachidonic acid

-nervonic acid

What are the essential fatty acids?

alpha linolenic acid has 18 carbons in total and 3 double bonds in total; the n-3 part means that counting from the end of the tail, the 3rd carbon has the first double bond

What does alpha-linolenic acid C18:3 n-3 mean? (What does each part of C18:3 n-3 mean?)

they are natural ligands to peroxisome proliferator-activated receptors (PPARs) which promote anti-inflammatory and anti-cancer effects

What is the biological importance of omega-3 fatty acids?

adipocytes

In animals, what type of cell are triacylglycerols stored in?

lipases

enzymes that hydrolyze fatty acid-glycerol ester bonds

primary

Are lipases more effective at working on primary or secondary esters?

1.glycerophospholipids

2.sphingolipids

3.cholesterol

What are the three types of lipids found in the cellular membrane?

niosome

non-ionic surfactant bilayer vesicle

micelle

single-layer lipid aggregate in water

liposome

spherical phospholipid bilayer vesicle

phosphatidic acid

precursor to many other common glycerophospholipids

glycerophospholipids have a glycerol backbone, whereas sphingolipids have a sphingosine backbone

What is the difference between glycerophospholipids and sphingolipids?

ceramide

Sphingosine derivative where a fatty acid is joined to a sphingolipid in amide linkage?

50%

What percent of the epidermal lipid matrix is ceramides?

25%

What percent of the epidermal lipid matrix is cholestrol?

15%

What percent of the epidermal lipid matrix is free fatty acids?

sphingosine derivative that are ceramides with one or more sugars in beta-glycosidic linkage at the 1-hydroxyl-group

cerebrosides

sphingosine derivatives that are glycosphingolipids with one sugar residue (usually glucose or galactose)

muscle and nerve cells

Where are cerebrosides typically found?

gangliosides

sphingosine derivative that is a ceramide with 3 or more sugars in which one is a sialic acid

sphingomyelin

sphingosine derivative that makes up myelin sheaths in neurons

cholesteryl ester

What does cholesterol become when it becomes esterified?

1.stress response

2.anti-inflammatory

3.glucose metabolism

What are the 3 biological roles of cortisol?

progesterone

What is the precursor of testosterone and estradiol?

1.progesterone

2.estradiol

3.testosterone

4.Vitamin D

5.Cortisol

What are the 5 different things that cholesterol can turn into with the help of enzymes?

bile acids

detergent-like molecules secreted by the liver and concentrated in the gallbladder that help in the emulsification and digestion of dietary lipids in the intestine

waxes

insoluble esters of long-chain alcohols with long-chain fatty acids

Carnauba wax

hard wax used for high-gloss finishes for automobiles, boats, floors, and shoes

Lanolin

wool wax used in cosmetics (oil of Olay)

Triacontanol palmitate

principle component of beeswax

terpenes

class of lipids formed from combinations of isoprene units

2-methyl-1,3-butadiene

What is the formula for isoprene?

two

How many isoprene units are in a monoterpene?

three

How many isoprene units are in a sesquiterpene?

four

How many isoprene units are in a diterpene?

retinal

visual pigment in rhodopsin; an example of a diterpene

phytol

an example of a diterpene found in chlorophyll

gibberellic acid

an example of a diterpene that acts as a plant hormone

terpene

All steroids are ____________-based

triterpenes

an example of a triterpene that is a constituent of wool fat and also a precursor to cholesterol and other steroids

tetraterpene

an example of a tetraterpene that is a carotenoid found in ripe fruit, especially tomatoes

albumin

carrier protein that carries free fatty acids through the bloodstream

saponification

process of making soap from fats by alkaline hydrolysis of ester bonds to produce glycerol and fatty acids

phospholipases A₁ and A₂

enzymes that cleave fatty acids from a glycerophospholipid producing lysophospholipids

phospholipases C and D

enzymes that hydrolyze on either side of the phosphorus in the polar head group

eicosanoids

signaling molecules made by the enzymatic oxidation of arachidonic acid or other polyunsaturated fatty acids

eicosanoids

What molecules do NSAIDs inhibit the synthesis of?