3. Lipids Flashcards
What are fatty acids?
Hydrophobic hydrocarbon chain with a terminal carboxyl group
What is a saturated fatty acid?
Single carbon bonds only
High flexible due to free rotation around single bonds
What are unsaturated fatty acids?
Contain one or more double bond
If there are more than one the bonds are placed at 3 carbon intervals
Position is specified by distance from carboxy end
What are essential fatty acids?
Cannot be made in the body
Linoleic acid and alpha linolenic acid
What conditions are associated with essential fatty acid deficiencies?
Scaly dermatitis
Visual and neurological abnormalities
What are prostaglandins?
Eicosanoids with a short half life
Roles in inflammation and platelet homeostasis
How are prostaglandins made?
By cyclooxygenase using arachidonic acid
What are leucotrienes?
Eicosanoids
Longer half life
Roles in inflammation and neutrophil adhesion
How are leucotrienes made?
By lipooxygenase using arachidonic acid
What is the function of TAGs?
Storage of energy in adipose tissue
What is the function of DAGs?
Intracellular signaller
Mobilisation of calcium
Which sphingolipid contains H as its R group?
Ceramide
Which sphingolipid contains phosphocholine as its R group?
Sphingomyelin
What group of sphingolipids contain sugar?
Glycosphingolipids
Which glycosphingolipid contains galactose or glucose?
Cerebroside
Which glycosphingolipid contains a sugar with sialic acid?
Ganglioside
What is characteristic of a steroid?
Fused ring system with a hydroxyl or keto group on carbon 3
Name some major classes of steroids
Cholesterol Bile acids Progesterone and adrenocortical steroids Androgens Estrogens
What are lipopolysaccharides?
Found in the outer membrane of gram negative bacteria
Endotoxins
Trigger strong immune response
What are terpenes?
Any of a class of organic compounds composed of two or more units of hydrocarbons
What does MCAD do?
Involved in mitochondrial fatty acid beta-oxidation
What are the main clinical signs of an MCAD deficiency?
Intolerance to prolonged fasting
Hypoglycaemia
Impaired ketogenesis
Recurrent episodes of hypoglycaemic come
How is an MCAD deficiency managed?
Avoid fasting
Glucose supplements
