[BIOCHEM LEC MIDTERMS] STRUCTURE OF LIPIDS & CLASSIFICATIONS

Fat

Our major long-term energy store

Lipids

Essential components of cell membranes and molecules involved in energy storage, hormones, signaling, insulation, and protection

lipids

Some ___ serve as precursors for hormones and signaling molecules

Fat and insulation

Fat provides insulation and helps protect organs

ADEK

Vitamins________ depend on dietary fat for absorption

Energy-storage lipids

Lipids that store energy for later use

Triacylglycerols

Example of energy-storage lipid

Membrane lipids

Lipids that form and maintain cell membranes

Phospholipids, sphingoglycolipids, and cholesterol

Examples of membrane lipids

Emulsifying lipids

Lipids that help break down and digest fats

Bile acids

Example of an emulsifying lipid

Messenger lipids

Lipids that act as chemical signals in the body

Steroid hormones and eicosanoids

Examples of messenger lipids

Protective lipids

Lipids that provide a protective, water-resistant coating

Biological waxes

Example of protective lipids

Fatty acid

Naturally occurring organic acid with one carboxyl group (–COOH)

Carboxyl group

Functional group written as –COOH

EVEN

Fatty acids usually have an ___ number of carbon atoms (ODD/EVEN)

C4–C6

Short-chain fatty acid

C8–C10

Medium-chain fatty acid

C12–C26

Long-chain fatty acid

RARELY

Fatty acids are ___ found alone and are usually attached to other molecules (RARELY/MOSTLY)

Complex lipids

Fatty acids attached to other molecules form more ___

Saturated fatty acid (SFA)

Fatty acid whose carbon chain has only single bonds between carbon atoms

Monounsaturated fatty acid (MUFA)

Fatty acid containing one carbon–carbon double bond (C=C)

cis

MUFA double bond usually occurs in the __ form

Polyunsaturated fatty acid (PUFA)

Fatty acid containing two or more carbon–carbon double bonds

six

Some important PUFAs have up to __double bonds

18:3(delta9,12,15)

Fatty acid notation representing 18 carbon atoms and 3 double bonds at positions Δ9, Δ12, and Δ15

Omega system

A system that groups unsaturated fatty acids according to the position of their double bonds counted from the methyl end

Methyl end

The end of a fatty acid from which the omega position is counted

Lauric acid

Medium-chain saturated fatty acid found mainly in coconut oil

Coconut oil

Lauric acid source

applications

May have antimicrobial, cleansing, drug-delivery, and tissue-engineering applications

Myristic acid

Saturated fatty acid naturally found in foods such as nutmeg

effects

May have effects against fungi, viruses, parasites, and cancer cells

derivatives

Compounds produced when scientists change the structure of myristic acid

NMT

Myristoyltransferase, an enzyme needed by certain cells and viruses

myristoyltransferase

some myristic acid derivatives can block this enzyme

Palmitic acid

A fatty acid present in high amounts in palm oil

Palm oil

A widely used vegetable oil found in foods such as margarine, cereals, sweets, and baked products

Margarine, cereals, sweets, and baked products

Foods containing palm oil listed in the lesson

type 2 diabetes

Studies suggest diets high in palm oil may reduce insulin sensitivity

increase cardiovascular

High intake of palmitic acid from palm oil may____ ____risk (increase/decrease) cvd

Arachidonic acid

A fatty acid involved in a pathway whose products, called eicosanoids, can affect cancer-related immune responses

Eicosanoids

Products of the arachidonic acid pathway that can help or weaken the immune system's ability to fight cancer

PD-1

shown in the arachidonic acid-related cancer pathway

COX-2 (cyclooxygenase)

an enzyme shown in the arachidonic acid pathway

PGE2 (prostaglandins)

a product associated with the COX-2 pathway

PGE2

___ can suppress immune responses

PGE2

___Suppression of immune responses can help tumor cells grow and avoid the immune system

Oleic acid

A monounsaturated fatty acid found mainly in olive oil

Olive oil

Oleic acid source

Mediterranean

Oleic acid is an important part of the ___ diet

macrophages, lymphocytes, and neutrophils

OA may influence these 3 immune cells

Palmitoleic acid

An omega-7 monounsaturated fatty acid found in plants and marine sources

Monounsaturated fatty acid (MUFA)

Palmitoleic acid classification

Plants and marine sources

Palmitoleic acid sources

both cis and trans forms

Palmitoleic acid forms

Eicosapentaenoic acid (EPA)

An omega-3 fatty acid that may help protect the heart and blood vessels

triglycerides

EPA can lower

plaque in arteries

EPA may reduce the formation of __ which can lead to heart disease

statins

purified epa + ___ may reduce the risk of major heart problems

Docosahexaenoic acid (DHA)

An omega-3 fatty acid important for development and proper function of the brain and eyes

Neuroprotectin D-1 (NPD-1)

A product of DHA that, together with DHA, helps protect brain cells from damage