DNA Structure Activity

Problem 3: Grooves in the DNA double helix

Examine the view labeled "phosphate group location". DNA does not have smooth sides like a regular cylinder. Notice the grooves in the surface of the DNA molecule between the phosphate groups. Proteins that interact with DNA often make contact in these grooves. How would you describe the grooves in the DNA surface?

A.	a single groove of uniform size
B.	a single groove that varies in size
C.	two distinct grooves, both of the same size
D.	two distinct grooves, one (the"major groove") is larger than the other (the"minor groove")