Clinical Biochemistry Lecture 3

What is the definition of complex lipids?

What is a characteristic of phospholipids?

What is the type of alcohol present in glycerophospholipids?

What is the function of phosphatidylcholine (lecithin) in the body?

What is the orientation of the polar group in a phospholipid bilayer?

What is the classification of phospholipids based on the type of alcohol present?

What is the name of the type of phospholipid that has sphingosine as the alcohol?

What is the name of the phospholipid that is found in cardiac tissue?

What is the primary function of surfactant in the lungs?

What is the main component of the myelin sheath found in nerves?

What is the characteristic of ceramide?

What is the typical sugar molecule found in cerebrosides?

What is the primary difference between sphingomyelin and glycolipids?

What is the consequence for a premature infant who lacks sufficient surfactant?

Complex Lipids

Compound lipids are esters of fatty acids containing groups in addition to an alcohol and one or more fatty acids.
Phospholipids are a type of compound lipid that contains an alcohol, fatty acid, phosphoric acid, and a nitrogenous base (choline, serine, inositol) or other alcoholic group.

Phospholipids

Phospholipids are classified into two types based on the type of alcohol present:
- Glycerophospholipids: contain glycerol as the alcohol
- Sphingophospholipids: contain sphingosine as the alcohol

Glycerophospholipids

Examples include:
- Phosphatidyl choline (lecithin)
- Phosphatidyl ethanolamine (cephalin)
- Phosphatidyl serine
- Phosphatidyl inositol
- Cardiolipins
- Plasmalogens

Phosphatidyl Choline (Lecithin)

The most abundant phospholipid in membranes
Represents a large proportion of body store of choline
Acts as an active agent "Surfactant" that lowers surface tension
Contains alcohol, fatty acid, phosphoric acid, and choline
Major surfactant produced by certain cells within the lung, preventing alveoli from collapse by decreasing surface tension between water and air

Sphingomyelin

A sphingophospholipid that does not contain glycerol but an unsaturated amino alcohol, sphingosine
Contains a molecule of choline, phosphoric acid, and a fatty acid
Makes up a large part of the myelin sheath found in nerves

Ceramide

Composed of sphingosine and a fatty acid joined by an amide bond
Common to all glycolipids and sphingomyelin

Glycolipids

Lipids containing a fatty acid, sphingosine, and carbohydrate
Examples include:
- Cerebrosides: contain a molecule of fatty acid, an amino alcohol sphingosine, and a sugar (usually galactose)
- Found in the white matter of the brain and myelin sheath of nerves

This quiz covers complex lipids, including phospholipids and glycolipids, as taught by Dr. Mariam Mohammed Ali in the Clinical Biochemistry Lecture 3 at Al-Ayen University's College of Medicine. It focuses on the key concepts and principles of clinical biochemistry.