Chapter 11: Lipids

Lipid

not soluble in water, but soluble in organic solvents; does not want to interact w water

1) Fatty Acid Structure

carboxylic acid (hydrophillic)

methyl group end

hydrocarbon (hydrophobic)

even # of carbons (16-18)

Saturated Fatty Acids

all single bonds between carbons

straight chains

can get tightly packed + stacked

solid at room temp

animal products, coconut + palm oils

may raise cholesterol levels in some people

Unsaturated Fatty Acids

contains one or more double bonds

cis double bonds create kinks in chain (same direction)

cannot pack tightly; more flexible

liquid at room temp

may help reduce cholesterol

plant oils, fish, nuts, avocados

Omega-3s (fish, walnuts) linked to heart
+ brain health

Palmiate

n-Hexadecanoate

Stearate

n-Octadecanoate

Palmitoleate

cis-∆⁹-Hexadecenoate

Oleate

cis-∆⁹-Octadecenoate

Linoleate

cis, cis-∆⁹, ∆¹²-Octadecadienoate

Linolenate

all-cis-∆⁹, ∆¹²-∆¹⁵-Octadecatrienoate

Systemic naming

begins from carboxylic acid end

n-

straight/ saturated chains

cis-

unsaturated chains

Essential Fatty Acids

cannot be synthesized by humans bc humans cannot make double bonds past 9th carbon from carboxyl end (need to be obtained from food)

crucial for brain development and cardiovascular health

Trans Fats

artificial fats with trans double bonds

raises bad cholesterol (LDL)

linked to heart disease and inflammation

Triaglycerols

ENERGY STORAGE

stored in adipose tissue fat cells

glycerol backbone + 3 fatty acids

anhydrous/no water weight

Phospholipids

fatty acids, phosphate group, and alcohol attached to platform (glycerol or sphingolipids)

form STRUCTURAL BACKBONE of cell membranes

can be broken down to release fatty acids

Phosphglyceride

phosphlipid with glycerol backbone

C3H8O3

Sphingolipid

Sphingosine back bone phospholipid

multiple carbons with hydrocarbon attached

Glycolipids

Cell Recognition

Cerebroside

simplest type of glycolipid

sphingosine backbone (long carbon chain)

Steroids

membrane fluidity/ buffer

3 cyclohexane rings 1 cyclopentane

testosterone, estrogen,

Lipid anchors

proteins that can covalently bind to lipid to localize to the cell membrane

Hutchinson-Gilford Pogeria Syndrome

rare genetic condition in which children age rapidly due to enzymes not cleaving farnesyl group from cell membrane