Wee 6 Structure And Function Of Lipids Flashcards

1
Q

Lipids

A

Biological lipids
-Chemically diverse
-Functionally diverse

  • Defining feature – insolubility in water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Storage lipids

A

Fats & oils principle form of stored energy for organisms -Are derivatives of fatty acids

  • Fatty acids – hydrocarbon derivatives
    -Triglycerides & waxes contain fatty acids

Highly exogonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Fatty acids

A

Carboxylic acids
Hydrocarbon chains 4 to 36 carbons long (C4 to C36)
Chains can be saturated (no double bonds) or unsaturated (contains double bonds)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Fatty acid nomenclature

A

Palmitic acid is abbreviated as 16:0

First carbon attached to carboxiliac end

Oleic acid is abbreviated as 18:1D9
Denotes position of double bond
Double bond Found at postion 9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Isomerism

A

Trans c are opposite sides of the double bind

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Polyunsaturated fatty acids (PUFAs)

A

Omega-3 (ω-3) fatty acids important role in nutrition
- Termed so due to position of double bond
- Double bond nearest methyl end is important so can label from that end
- Omega-6 fatty acids – double bond between carbon 6 & 7 From methyl end
(Opposite from carboxylic end )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Omega-3 fatty acids

A

umans require but lack ability to synthesise α-linolenic acid (ALA; 18:3D9,12,15)
Must obtain from diet

-From ALA can synthesise
— Eicosapentaenoic acid (EPA; 20:5D5,8,11,14,17)
— Docosahexaenoic acid (DHA; 22:6D4,7,10,13,16,19)
Chia, walnuts, kiwi seeds

Imbalance of omega-6 & -3 can = risk of CVD
- Optimal ratio omega-6 to -3, 1:1 to 4:1  Ratio in N.
—American diets, 10:1 to 30:1
—‘Mediterranean diet’ rich in omega-3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Fatty acids

A

Physical properties
—Determined by length & degree of unsaturation
— Solubility – longer the chain & fewer the double bonds = lower solubility in water

Melting point – greater number of unsaturated/double bonds
—Lower melting point
— Double bonds = ‘kink’ in tail = reduced packing of fatty acids

Glucose Oxygen is electronegative = pull electrons towards it leaving hydrogen electro postive = solubility in h20 is higher

Saturated fatty acids = lots together, van de waals bonds

Unsaturated fatty acids kinks = unable to line up, Limited van de waals bonds, less heat to melt it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Triglycerides

A

Also known as triacylglycerols, fats or neutral fats

—Triglyceride structure = 3 fatty acids, 3 ester bonds, 1 glycerol

Non polar = hydrophobic, insoluble in water

Triglycerides provide stored energy & insulation
—Form separate phase in aqueous cytosol – droplets of metabolic fuel
— Adipocytes store fat droplets (nuclei pushed out to edge of plasma membrane)(not many mitochondria)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Energy from fats

A

Fats = 9 cal per gram, not many o2, highly reduced, don’t carry water as there insoluble
Protien = 4 cal per gram
Carbs = 4 cal per gram

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Storage from fats

A

White adipose under are skin
Acts as insulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Partial Hydrogenation of cooking oils

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Hydrogenation of oleic acid

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Wax

A

Biological waxes – esters of long chain fatty acids (c14 – C36) + long chain alcohols (c16 – C30)

Insoluble due to the lack of oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly