Lipids

1.

1 point

Which of the following is NOT typically a storage lipid?

Phospholipids

Fatty acids

Triacylglycerols

Stearate

2.

1 point

Fatty acids contain a carboxylic group with a charge of (a) _____ at physiological pH, and a hydrocarbon chain that is (b) _____ carbons long.

(a) -1 (b) 4 - 36

(a) -2 (b) 4 - 36

(a) -2 (b) 1 - 40

(a) -1 (b) 1 - 40

3.

1 point

Stearate (n-octadecanoic acid) is a fully saturated fatty acid. Which of the following is true?

18:0 (10 carbons, 0 C=C bonds) could possibly represent stearate.

18:2 (10 carbons, 2 C=C bonds) could possibly represent stearate.

Stearate cannot be amphipathic.

Stearate will have a low melting point because single bonds decrease melting point.

4.

1 point

Which of the following is NOT true for saturated fatty acids?

They disrupt tight packing, lowering the melting point.

They can pack into a nearly crystalline array stabilized by hydrophobic interactions.

The carbon backbone is usually in a fully extended conformation.

They have a carboxyl head group, and an acyl chain for a tail.

5.

1 point

Which of the following is NOT likely to be true for unsaturated fatty acids?

Oleate (cis-9-octadecenoic acid) could be represented by 18:1 Δ^9.

They will generally have a lower melting point compared to saturated fatty acids.

If there are several double bonds, they will usually be conjugated.

Double bonds in unsaturated fatty acids are usually cis.

6.

1 point

Which of the following is NOT true for triacylglycerols?

Simple triacylglycerols have 3 identical fatty acids.

The fatty acids have ester linkages to the glycerol.

3 fatty acids attach to the 3 –OH groups of a glycerol.

Mixed triacylglycerols have different fatty acids, but all 3 must be either unsaturated or saturated – saturated and unsaturated can’t attach to the same glycerol.

7.

1 point

Which of the following is NOT typically a structural lipid for cell membranes?

Terry Mulhern.

Glycolipids.

Phospholipids.

Sterols.

8.

1 point

Phospholipids:

Have a polar head group like PO4-alcohol or PO4-choline.

Are not amphipathic.

Are defined by 3 phosphate (PO4) groups in each polar tail.

Can be divided into glycerophospholipids and sphingoglycerols/sphingophosphoglycerols.

9.

1 point

Glycerophospholipids:

Are a large group of storage lipids that make up the majority of adipose tissue.

Can be further defined with additional substituents which attach to the head group.

All have a -1 charge from the head group.

Are located on the outer membrane leaflet of blood cells, designating them into blood group A, B, AB, or O.

10.

1 point

Sphingolipids:

Are derived from the amino alcohol ‘sphingoglycerol’.

Have a sphingosine as the polar head that is attached to 2 tails.

Don’t always contain a phosphate group. For example, the sphingosine can become a glycolipid and attach to a mono- or oligosaccharide, which acts as the polar head instead.

Generally contain glycerol.

Lipids - 1