Biochemistry Lipids and Membranes

Question 1

Which type of fatty acid contains one double bond?

Accepted Answer

Monounsaturated fatty acid

Answer

Saturated fatty acid

Answer

Polyunsaturated fatty acid

Answer

Trans fatty acid

Question 2

The fluid mosaic model of the cell membrane was proposed by:

Accepted Answer

Singer and Nicolson

Answer

Watson and Crick

Answer

Mitchell and Moyle

Answer

Lipmann and Krebs

Question 3

Which lipid class forms the structural backbone of the cell membrane bilayer?

Accepted Answer

Phospholipids

Answer

Triglycerides

Answer

Cholesterol

Answer

Sphingomyelin

Question 4

Cholesterol in animal cell membranes functions to:

Accepted Answer

Modulate membrane fluidity

Answer

Increase membrane permeability to ions

Answer

Serve as the primary energy storage lipid

Answer

Provide receptor sites for hormones only

Question 5

Eicosanoids (prostaglandins, thromboxanes, leukotrienes) are derived from which fatty acid precursor?

Accepted Answer

Arachidonic acid (20:4)

Answer

Palmitic acid (16:0)

Answer

Stearic acid (18:0)

Answer

Linoleic acid (18:2)

Question 6

What is the term for the movement of a phospholipid from one leaflet of the bilayer to the other?

Accepted Answer

Flip-flop (transverse diffusion)

Answer

Lateral diffusion

Answer

Rotational diffusion

Answer

Vesicle budding