CEE 2 - BIOCHEM Lipids, Fatty Acids,Triglycerol, Lipoproteins, Cholesterol

___are heterogeneous group of compounds relatively insoluble in water and freely soluble in nopolar organic solvents (ether, chloroform)

Lipids

• Unlike carbohydrates & proteins, ___ are not chemically related, but are physically related (in terms of solubility to nonpolar organic solvents)

• They are not true polymers, unlike carbohydrates & proteins

Lipids

Lipids function

•lmportant constituent of diet

•Storage form of energy

•Provide thermal insulation

•Serve as electrical insulators of myelinated nerves

Are carboxylic acids with a long aliphatic hydrocarbon chain

Fatty Acids

The R group of fatty acids accounts for the___ nature of fat

nopolar

Length of Short chain FA

C2-C6

Length of Medium chain FA:

C8-C14

Length of Long chain FA:

At least C16

Length of Very long chain FA:

At least C22

Saturated FA or Unsaturated FA?

• NO DOUBLE BOND in the hydrocarbon chain

• FA is saturated with hydrogen

• Means that all C-C bonds are single bonds

Saturated FA

Saturated FA or Unsaturated FA?

• AT LEAST ONE DOUBLE BOND in the

  hydrocarbon chain is present

Unsaturated FA

What FA?
ONLY 1 DOUBLE BOND is present

Monounsaturated FA

What FA?

MORE THAN 1 DOUBLE BONDS are present

Polyunsaturated FA

Geometric isomerism

H atoms are found on the SAME SIDE

Cis-form

Geometric isomerism

H atoms are found on the OPPOSITE SIDE

Trans-form

What FA?

• 12:0

• Predominant FA in coconut oil

Lauric acid

What FA?

• 16:0

• End-product of mammalian FA synthesis

Palmitic acid

What FA?

• 18:1 (9)

• Predominant FA in olive oil

Oleic acid

What FA?

• 18:2 (9,12)

• Essential fatty acid

Linoleic acid

What FA?

• 18:3 (9,12,15)

• Essential fatty acid

alpha-Linolenic acid

What FA?

• 20:4 (5,8,11,14)

• Precursor of eicosanoids

• Semi-essential fatty acid - because it can be derived from Linoleic acid

Arachidonic acid

Fatty acids that are required by humans (since they are not synthesized in the body)

Essential Fatty Acids

Essential Fatty Acids:

Humans lack the enzymes that can introduce double

bonds beyond the ___

9th carbon

Essential FAs examples

• Linoleic acid

• alpha-Linoleic acid

Semi essential FA example

Arachidonic acid

Essential FAs lower what risk?

cardiovascular disease and fatty liver disease

• Integral components of membrane structure

• Needed for the synthesis of arachidonic acid (parent compound of the eicosanoids - prostaglandins, prostacyclin, leukotrienes, thromboxane)

Esential FAs

Omega Fatty Acids depends on the position of the ____

first double bond from the terminal methyl end

Omega 3 series

• alpha-Linolenic acid

• Timnodonic acid (eicosa-pentaenoic acid)

• Cervonic acid (docosahexaenoic acid) (DHA)

Timnodonic acid is also known as?

eicosa-pentaenoic acid

Cervonic acid is also known as?

docosahexaenoic acid (DHA)

Omega 6 series

• Linoleic acid

• Arachidonic acid

Omega 9 series

• Oleic acid

• Elaidic acid

Significance of Omega 3 series (3)

• Decreases serum triglycerides

• Lowers the production of thromboxane

• Important for infant development

Significance of Omega 3 series:

Decreases serum triglycerides leads to?

decrese risk of cardiovascular disease

Significance of Omega 3 series:

Lowering the production of thromboxane leads to?

decrease tendency for platelet aggregation

____ is a derivative of arachidonic acid, an omega-6 FA. Increasing the intake of a-3 FAs will decrease the relative concentration of your a-6 FAs

Thromboxane

___ the intake of a-3 FAs will decrease the relative concentration of your a-6 FAs

Increasing

___ is synthesized from a-Linolenic acid. It is needed for the development of fetal brain and retina.

DHA

Simple lipids (3)

Fats, Oils, Waxes

Complex lipids (5)

Phospholipids

Glycolipids

Lipoproteins

Sulfolipids

Aminolipids

Precursor of derived lipids (7)

Fatty acids

Glycerol

Steroids

Ketone bodies

Hormones

Fat-soluble vitamins and

Micronutrients

Simple lipids is made of

Fatty acid + Glycerol

Are esters of fatty acid + alcohol

Simple lipids

what simple lipid?

Solid at room temperature

Fats

what simple lipid?

Liquid at room temperature

Oils

Complex lipid is made of?

Fatty acid + Glycerol/Sphingosine + Additional groups

Are (esters of fatty acid + alcohol) + additional groups

Complex lipids

Additional groups of complex lipids can be ___

phosphoric acid, carbohydrates, proteins

Triacylglycerol is composed of

3 Fatty acids + Glycerol

Triacylglycerol is formed by linking fatty acids with an ___ to 3 alcohol groups in glycerol

ester linkage

Main storage form of lipids in the body - stored in the adipose tissues

Triacylglycerol

Triacylglycerol is also known as

triglyceride, neutral fat

Lipoproteins is composed of

Lipids + Apolipoproteins

Lipoproteins structure consists of

core and shell

Lipoproteins core or shell?

Neutral lipids

Core

Lipoproteins core or shell?

Amphipathic apolipoproteins, phospholipid, and free fatty acids

Shell

Lipoproteins function

• Keep lipids soluble in plasma

• Provide an efficient transport mechanism for lipids to and from various tissues

You need ____ to transport triglycerides and fatty acids in the blood because these compounds are nonpolar.

lipoproteins and albumin

Lipoprotein pertains to the whole structure. _____ pertains to just the protein component.

Apoprotein or apolipoprotein

Deposition of cholesterol and cholesteryl esters in the artery walls especially from oxidized LDL

Atherosclerosis

___ cause endothelial damage which predisposes to atherosclerosis

Oxidized LDLs

More severe in diabetes mellitus, lipid nephrosis, hypothyroidism

Atherosclerosis

• 27-carbon compound

• Steroid nucleus: four fused hydrocarbon rings (A-D)

• An eight-carbon, branched hydrocarbon chain attached to carbon 17 of the D ring

• Hydroxyl group at carbon 3 of the A ring

• Double bond between carbon 5 and 6 of the B ring

Cholesterol

An important steroid in animal tissues

Cholesterol

Adults normally synthesize approximately___ and consume about ____ per day

1 g, 0.3 g

Cholesterol is stored as

cholesteryl esters (cholesterol + fatty acid chain)

Cholesterol derivatives

Bile, Adrenal and Sex hormones, Vitamin D

Bile enzyme

7a-hydroxylase

rate-limiting step in bile acid synthesis

7a-hydroxy-cholesterol

Bile products

Primary bile acids, Secondary bile acids, bile salts

Bile acids synthesized by the liver

Primary bile acids

Primary bile acids examples

• Cholic acid

• Chenodeoxycholic acid

bile acids resulting from bacterial degradation in the colon

Secondary bile acids

Secondary bile acids examples

• Deoxycholic acid (from cholic acid)

• Lithocholic acid (from chenodeoxycholic acid)

Conjugated to taurine and glycine (e.g., taurocholic acid, glycocholic acid)

bile salts

Adrenal and Sex Hormones enzyme

Desmolase

Adrenal and Sex Hormones:

Cholesterol → ___

Pregnenolone

Adrenal hormones products

Glucocorticoids (Cortisol),

Mineralocorticoids (Aldosterone)

Sex Hormones products

Testosterone, Estradiol

Vitamin D product

7-dehydrocholesterol