Lipids

Fats, Oils and Other Things

Lipid BasicsMade of C,H,Omonomer = glycerol + fatty acidshydrophobic - don’t dissolve in water

oil and water don’t mix

Fatty Acids2 types – saturated and unsaturated- What’s the difference?

- saturated fatty acids contain no double bonds

between C atoms - holds the maximum # of H atoms

- unsaturated fatty acids contain double bonds between C

atoms atoms

Lipids- Fats and Oils…energy insulation and more

• Fats & Oils (triglycerides)- long term energy storage

•Fat has twice the calories of carbohydrates.

– fat = 9 cal/g sugar= 4 cal/g

–Lipids have more C – H bonds which store energy

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Health tip:

Saturated or hydrogenated fats(bad) vs. unsaturated (good)

Lipids: types and functions

Fats/Oils – long term energy storage, insulation and protection

Phospholipids – cell membranesSteroids – make hormones (chemical

messengers)Waxes – waterproofing

Fats• Solid at room temperature• Energy storage in animals• contain saturated fatty acids

Saturated fat and fatty acid

Stearic acid

Body Fat – stores energy, insulates and protects the organs

Excess energy is converted to fat Sea mammals rely on

fat to keep them warm

Oils • energy storage in plants• contain unsaturated fatty acids• liquid at room temperature

Unsaturated fat and fatty acid

Double bond causes molecule to bend

Oleic acid

Phospholipids-• Glycerol• only 2 fatty acids (not 3 like fats and oils)

• 3rd fatty acid is replaced by a phosphate molecule

SPONCH

Phospholipid structurePhosphate molecule forms a hydrophilic

(water loving) head• Fatty acid molecules make up a

hydrophobic tails

CH2

OPO OOCH2

CH

CH2 OO

C O C O

Phosphate

Glycerol

(a) Structural formula (b) Space-filling model

Fatty acids

(c) Phospholipid symbol

Hyd

rop

hob

ic t

ails

Hydrophilichead

Hydrophobictails

–

Hyd

rop

hilic

head

CH2 Choline+

Figure 5.13

N(CH3)

3

Phospholipids create the structure of cell membranes2 layers of phospholipidsPhosphates face out – interact with waterLipid tails make a middle layer that repels

water Phospholipids separate the contents of the

cell from it’s surrounding environmentHydrophilichead

WATER

WATERHydrophobictail

myelin - phospholipid that insulates nerve cells

We are all literally “Fatheads”

Lipids- Cholesterol•connected rings of carbon• component of cell membrane – adds to the integrity of the membrane • used to make steroids

Steroids: Lipids that act as Hormones Hormones are chemical messengers

- produced in one part of the body, they travel to and cause changes in another part of the body

- Hormones control: growth development tissue function sexual function the way our bodies use food, the reaction of our bodies to emergencies,

mood

- examples estrogens testosterone

Estrogen Testosterone

Steroids are Derived From Cholesterol

Estrogen Testosterone

Waxes-Lipids that repel water - found on the surface of leaves - found on animal hair to keep it pliable - found on the feathers of water birds to

prevent them from becoming waterlogged

Flashcards for Your Learning Pleasurelipid basicssaturated fatty acidsunsaturated fatty acidshydrophobic hydrophilicfatsoilsphospholipidsmyelincholesterolsteroidshormoneswaxes