Module 5: Lipids

3

Glycerol contains how many carbon atoms?

Phosphoglycerides

Which of the following are derived from or made from fatty acids?

glycerol; three fatty acids

Triacylglycerols are made from a ________ and ________.

PUFA

Polyunsaturated fatty acid (2 or more double bonds)

none of the above

A ________ is a carboxylic acid that is a structural component of lipids.

Oil

A particular lipid is a liquid at room temperature, so it is called a(n) ________

Peripheral protein

________ are a class of membrane proteins that are loosely associated with the membrane bilayer.

14:1 Delta 3

Which notation indicates a 14-carbon omega-3 fatty acid that contains no other double bonds?

Glycerol

__________ is used as the backbone molecule in the formation of storage fats

Sphingolipids

__________ molecules determine blood type in humans.

Sphingolipids

________ are found in high concentrations in the membranes of the myelin sheath.

Amide linkage

In a sphingolipid, the fatty acids are attached at carbon-2 by this type of linkage?

Can be chemically separated from the membrane

Peripheral membrane proteins

The membrane is fluid

Which statement best describes a general feature of membranes?

Vitamin K

Which vitamin is critical for blood coagulation?

None of these

What molecule is not found in membrane bilayers?

What molecule that protects against UV rays is found both in bacteria and in the eyes?

Cholesterol

What molecule has four fused rings in its structure?

-O-CO-

In triacylglycerols, fatty acids are attached to glycerol via ______ linkage.

A molecule that dissolves in a non-polar solvent

A lipid is __________.

Fatty acids with double bonds are referred to as unsaturated fatty acids. Most double bonds cause the fatty acids to bend or kink about in solution. This kinking reduces the packing structure of fatty acids making them more liquid-like.

What is the effect of a double bond on structure of fatty acids?

In the cell. The cell, itself, and the organelles have membranes.

Where in the body are membranes found?

Sphingolipids contains a ceramide. The purpose of this lipid is to form the structure of membrane bilayers and in the myelin sheath of neurons. They also aid in defining blood type in individuals.

What type of lipid contains a ceramide? What is the purpose of this lipid?

Phosphoglycerides have two fatty acid attached to the glycerol. Triacylglycerols have three fatty acids. Phospoglycerides also have a polar head group attached.

What is the most significant chemical difference between triacylglycerols and phosphoglycerides that lead to their different functions?

The fluid mosaic model helps us understand biological membranes. It describes the fluid, complex nature of the membrane bilayer. Membranes have lipids and proteins in a rich mixture to help the cell survive.

What is the fluid mosaic model and what feature of the cells does it help us understand?

The lipid definition is based on the functional definition of being soluble in a non-polar solvent. Proteins and carbohydrates are based on the structure.

How is the definition of lipid different from protein and carbohydrate?

energy & storage, vitamin, structure, and waxes

What are the functions of lipids?

The simplified notation starts number at the carboxylic acid, while the omega system starts at the opposite end - from the -CH3.

How does the omega numbering system differ from the simplified notation?

They serve as blood group determinants, the structure of membrane bilayers, and in the myelin sheath of neurons.

Describe at least two functions of sphingolipids.

Sphingolipids have a ceramide backbone structure, whereas the phosphoglycerides have a glycerol structure.

What is the main difference between phosphoglycerides and sphingolipids?

5 carbons and one double bond

How many carbons and double bonds are in an isoprene unit?

phosphoglycerides, cholesterol, sphingolipids, integral proteins, and peripheral proteins

Name three components of a cellular membrane.

3

Glycerol contains how many alcohol functional groups?

20:1(Δ17)

Which SIMPLIFIED NOTATION indicates a 20-carbon omega-3 fatty acid that contains NO other double bonds?