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Flashcards in Lipids 1 Deck (20)
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1
Q

Define lipids.

A

Heterogeneous organic molecules which are insoluble in water but soluble in organic solvents.

2
Q

Where are lipids found?

A

Cell membranes
Lipid droplets in adipose tissue
Blood lipoproteins.

3
Q

What are the 6 functions of lipids?

A
Stored form of energy
Structural energy of membranes
Enzyme cofactors
Hormones
Vitamins A, D, E and K
Signalling molecules
4
Q

Name the 5 classes of lipids.

A
Fatty Acids
Triacylglycerols
Phospholipids
Glycolipids
Steroids.
5
Q

What are the 4 types of fatty acids?

A

Essential Fatty Acids - found in plants
Good Fats - high in polyunsaturated fatty acids
Bad Fats - high in saturated fatty acids, needed for myelination
Really Bad Fats - trans fatty acids, result from hydrogenation of vegetable oil

6
Q

Define essential fatty acids.

A

Must be ingested. Arachidonic acid is a precursor of eicosanoids and can be synthesised from linoleic acid.

7
Q

What can a deficiency of essential fatty acids result in?

A

Growth retardation, chronic intestinal diseases and depression.

8
Q

Define triacylglycerols.

A

Esters of fatty acids and glycerol. Uncharged lipids which are water insoluble and necessary for dietary fuel.

9
Q

Define phospholipids.

A

Composed of glycerol and are amphipathic. Hydrolysed to fatty acids and lysophospholipids.

10
Q

Define bile salts.

A

Derivatives of cholesterol and act as biological detergents to form emulsions and mixed micelles.

11
Q

Define cholesterol esters.

A

Make up 15% of dietary lipids and are digested to cholesterol and free fatty acids.

12
Q

What is the process of the digestion of lipids?

A

Fat -> Emulsified fats -> Fatty Acids and Glycerol

13
Q

What is steatorrhea?

A

Lipid malabsorption.

14
Q

How are fatty acids transported around the body?

A

A solubilising protein is added and they’re packaged into chylomicrons which are released in to lymph then blood by exocytosis.

15
Q

What is the enzyme which hydrolyses triacylglycerol?

A

Lipoprotein lipase.

16
Q

Where do used chylomicron remnants go?

A

Liver where glycerol is used in glycolysis and gluconeogenesis.

17
Q

Triacylglycerols are stored as ______ and are the ______ efficient storage form of fuel.

A

Droplets, most.

18
Q

How are free fatty acids transported through the blood?

A

Complex serum albumin which has 2-7 binding sites for fatty acids.

19
Q

What are lipoproteins made up of?

A

Cholesterol esters, triacylglycerol and phospholipids.

20
Q

Lipoproteins are classified in terms of density so what is the order from least dense to most dense?

A

Chylomicrons
VLDL
LDL
HDL