Question

12. In simple diffusion a solute

A. Is propelled by random molecular motion

B. Moves up its concentration gradient

C. Moves across a membrane because of an input of free energy.

D. Both A and B are correct

E. All of the above are correct

16. Lipolysis is used to

A. Degrade triacylglycerols

B. Prepare triacylglycerols for excretion

C. Remove lipid from membrane

D. Cleave fatty acids into two carbon units

E. Convert fatty acids to glucose

19. The myelin sheath

A. Surrounds nerve cell axons

B. Contains large amounts of cardiolipin

C. Facilitates nerve impulse transmission

D. Both A and B are correct

E. Both A and C are correct

20. Membrane proteins are linked to anchor molecules through a ___________ link

A. Ether

B. Ester

C. Amide

D. Amino

E. Plasma

22. Patients with familial hypercholesterolemia

A. Possess depressed levels of plasma cholesterol

B. Have missing or defective LDL receptors

C. Are homozygous or heterozygous for a nonfunctional LDL receptor gene

D. Have very high levels of serum cholesterol

E. B, C and D are correct

Answer 1

12)The simple diffusion is the random movement of molecules from their high concentration to their low concentration.This movement is passive transport and downhill and does not require energy in the form of ATP.So the right answer is A)

The example of simple diffusion is the carbon dioxide and oxygen dissolved in the blood.

16)The lipolysis is the breakdown of the triacylglycerol or fats into glycerol and fatty acids.This involves the word lysis which means breakdown of triglycerides in to the diglycerides and then the monoglycerides.The lysis of fatty acids into two carbon subunit (acetyl CoA) is the oxidation of fatty acids.Conversion of fatty acids into glucose intermediates is known as gluconeogenesis.So the right answer is degrade triacyl glycerols.

19)The myelein sheath is present on the axon and help in the fast transmission of the nerve impulses.Their are nodes of Ranvier in the myelein heath which is not covered with the insulated lipid material.Therefore there would be faster transmission of the impulse from one node to the other.In non myelienated nerve fibre the signal has to travel whole along the axon.The myelein sheath contain lipid,protein,cholestrol,lecithin etc.So the right answer is both a and c are correct.

Please ask the other question separately.