Lipids Part 1

Lipid classifications (3/4)

Simple, complex, and precursor/ derived

Simple lipids (3)

fats, oils, waxes

What is the difference between fats and oils?

Fats are solid at room temperature and oil is liquid at room temperature

What are fats and oils?

Esters of fatty acids with glycerol also known as trigycerides

Lipids are insoluble in water because...

They are hydrophobic and dormant micelles in water (some exceptions)

Lipids are soluble in what kind of solvent?

Non-polar, organic solvents

Lipids are a homogenous group of compounds- T or F

False

What are waxes?

Esters of fatty acids with high molecular weight alcohol

Complex lipids (2)

Phospholipids, glycolipids

Precursor/ derived lipids (4)

Fatty acids, glycerol, steroids, ketone bodies

Dietary fat mostly comes in the form of...

Triglycerides

Two ingredients of feed with highest lipid content according to ether extract

DDGS, fish meal

Fats added to feed (5)

Tallow, lard, yellow grease, poultry fat, animal/ vegetable

Quality criteria for feed fats (7)

Moisture, impurities, unsaponifiables (1-2%), titre/hardness, free fatty acid (<2%), total fatty acids (90% min)

Lipids are ____ more energy than CHO

2.25x

Lipids are sources for... (5)

Essential patty acids, fat soluble vitamins, thermal insulation, electrical insulation, and membrane components

How is lipid a source for thermal insulation?

Adipose tissue

How is lipid a source for electrical insulation

Nerve impulses

How is lipid a source of membrane components?

Phospholipid bilayer

Fats improve feed by...

Improving palatability, decreasing dust

What is titre/ hardness

Melting point

Energy from fat is greater than CHO because...

Fat has more carbons

Why is dietary fat important in animal nutrition?

Dust control and energy source

Limitations to dietary fat in general

Dietary fat increases carcass fat

Limitations to dietary fat in ruminants

Excess fat inhibits rumen microorganisms

Limitations to dietary fat in nonruminants

Type of fat directly impacts carcass quality (unsaturated/ saturated)

Government recommendations on human fat consumption (3)

Decrease total fat (<30% net calories), increase unsaturated fat, increase omega-3 and decrease omega-6

Human health issues related to fat (3)

Obesity, heart disease, cancer

Human health issues related to fat- obesity

Excess caloric consumption

Human health issues related to fat- heart disease (3)

Cholesterol, saturated after, trans fatty acids

Human health issues related to fat- cancer

Saturated fat

Main component in dietary lipid is...

Triglycerides

Triglyceride composition

One glycerol (10%) linked to three fatty acids (90%) through an ester bond

Fatty acids are turned into glycerol through which process

Esterification

Fatty acid main functional groups (2)

Hydrocarbon chain, carboxyl group

Hydrocarbon chain length

Variable

Hydrocarbon chain solubility

Water insoluble

Carboxyl group pK

2-3

Saturated fatty acid chain shape

Straight chain

Unsaturated fatty acid chain chape

Bent due to double bond

Think of saturated of fatty acids as all the carbons are...

Saturated with hydrogen atoms (biohydrogenation turns unsaturated fatty acids into saturated)

Short chain fatty acid length

2-6 C

Medium chain fatty acid length

8-12 C

Long chain fatty acid length

14-24 C

As chain length increases, what happens to melting point?

Increases

Fatty acids synthesized by plants and animals chain characteristics (2)

Even number C, mostly long chain

Microorganisms synthesize fatty acid chains of...

Odd number of C

Odd chain fatty acids are not utilized as good as even chain fatty acids- T or F

True (TCA 2C at a time)

Saturated short volatile fatty acids (3)

Acetate, butyrate, caproic (hexanoic)

Symbol of fatty acid meaning: example C 18:9

18- carbon length, 9- number of double bonds

Saturated medium chain fatty acids (3)

Caprylic (octanoic), capric (decanoic), lauric (dodecanoic)

Saturated long chain fatty acids (3)

Myristic (tetradecanoic), palmitic (hexadecanoic), stearic (octadecanoic)

Monounsaturated fatty acids have how many double bonds?

1

Polyunsaturated fatty acids have how many double bonds?

2 or more

Unsaturated fatty acids are usually in which configuration?

Cis

Cis configuration in unsaturated fatty acids are better because...

They allow for fatty acid curvature which compacts it allowing less tangling with neighboring molecules

Where can trans unsaturated fatty acids be found?

Rumen microorganisms and in chemical hydrogenation

Position of the bonds in unsaturated fatty acids are important- T or F

True

As the number of double bonds increase, melting point...

Decreases

With trans configuration, unsaturated fatty acids resemble...

Saturated fatty acids due to lack of bending

Unsaturated fatty acid 16 C (2)

Palmitate (C16:0), plamitoleic (C16:1)

Unsaturated fatty acid 18 C (4)

Stearate (C18:0), oleic (C18:1), linoleic (C18:2), linolenic (C18:3)

Unsaturated fatty acid 20C (3)

Arachidic (C20:0, eicosanoic), gadoleic (C20:1), arachidonic (C20:4, eicosatetraenoic)

Delta unsaturated fatty acid identification of double bond location

Count from carboxyl end

Omega (w/n) unsaturated fatty acid identification of double bond location

Count from methyl end

Linoleic acid delta and omega nomenclature

18:2 delta 9,12; 18:2 n-6

Oleic acid delta and omega nomenclature

18:1 delta 9; 18:1 n-9

As mammals, we do not have enzymes to place double bonds...

Before the ninth carbon

Common unsaturated fatty acids

Palmitic, stearic, oleic, linoleic, alpha linoleic, arachidonic, EPA, DHA

Omega 3 fatty acids can be converted to omega 6 fatty acids- T or F

False

Mixed triglyceride fatty acids

Pamitate, oleate, stearate

Saturated fat examples (2)

Animal fat, hydrogenated plant oil

Saturated fats effect on serum cholesterol

Increases

Unsaturated fat examples (2)

Plant oil, fish oil

Unsaturated fats effect on serum cholesterol

Decreases

Monosaturated fat like olive oil is good for you- T or F

True

Trans unsaturated fats are good for you- T or F

False

Eicosanoids are present in plants- T or F

True

Types of lipids (4)

Triglycerides, phospholipids, steroids

Source of trans fatty acids

Hydrogenated fats

Biohydrogenation produces some trans fatty acids- T or F

True

Soy oil to crisco process

Hydrogenation, heat, catalyst, H2

Trans fatty acids are not essential and provide no known health benefits except for

Conjugated linoleic acid

Trans fatty acids contain one or more trans linkages that are in a conjugated system- T or F

False- are not

Which desaturase enzymes do animals have?

Delta 4,5,6,9

Which desaturase is needed to synthesize linoleic acid?

Delta 12

Which desaturases are needed to synthesize linolenic acid?

Delta 15

Stearate to oleate utilizes which desaturase?

Delta 9

Which desaturase do cats lack?

Delta 6

Fatty acids stay in the same family- T or F

True

Animals can insert double bonds after carbons...

4-9

Animals can add ___ carbon units

2

Stearic cannot be made into oleic- T or F

False- can

Linoleic can be made into arachidonic- T or F

True

Oleic cannot be converted into...

Linoleic or linolenic

Essential fatty acids (5)

Linoleic, alpha linolenic, arachidonic, EPA, DHA

PUFA

Polyunsaturated fatty acid

Essential fatty acid deficiency is very...

Rare

Most common essential fatty acid deficiency is

Dermatitis or skin issues

Human essential fatty acid requirements

Not accurate because it is hard to do research on humans