Lipids 1 Flashcards Preview

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Flashcards in Lipids 1 Deck (20):
1

Define lipids.

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

2

Where are lipids found?

Cell membranes
Lipid droplets in adipose tissue
Blood lipoproteins.

3

What are the 6 functions of lipids?

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

4

Name the 5 classes of lipids.

Fatty Acids
Triacylglycerols
Phospholipids
Glycolipids
Steroids.

5

What are the 4 types of fatty acids?

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

Define essential fatty acids.

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

7

What can a deficiency of essential fatty acids result in?

Growth retardation, chronic intestinal diseases and depression.

8

Define triacylglycerols.

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

9

Define phospholipids.

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

10

Define bile salts.

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

11

Define cholesterol esters.

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

12

What is the process of the digestion of lipids?

Fat -> Emulsified fats -> Fatty Acids and Glycerol

13

What is steatorrhea?

Lipid malabsorption.

14

How are fatty acids transported around the body?

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

15

What is the enzyme which hydrolyses triacylglycerol?

Lipoprotein lipase.

16

Where do used chylomicron remnants go?

Liver where glycerol is used in glycolysis and gluconeogenesis.

17

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

Droplets, most.

18

How are free fatty acids transported through the blood?

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

19

What are lipoproteins made up of?

Cholesterol esters, triacylglycerol and phospholipids.

20

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

Chylomicrons
VLDL
LDL
HDL