Watson-Crick Model of DNA Structure

Question 1

What does the Watson-Crick model state?

Answer 1

cellular DNA is a right handed double helix linked together by hydrogen bonds and hydrophobic forces between bases

Question 2

Is DNA single or double stranded?

Answer 2

double stranded

Question 3

What is the basic structure of the double strand?

Answer 3

two polynucleotide chains are hydrogen bonded together in an antiparallel direction

Question 4

What does it mean for DNA to be antiparallel?

Answer 4

the 5’ end of one chain pairs with the 3’ prime end of the other chain

Question 5

What forms the hydrogen bonding?

Answer 5

between bases on adjacent chains

Question 6

Which bases can hydrogen bond to each other and how many do they form?

Answer 6

A= T, two hydrogen bonds
C = G, three hydrogen bonds

Question 7

What is annealing/hybridization?

Answer 7

binding of two complementary strands of DNA

Question 8

What is melting/denaturation?

Answer 8

separation of complementary strands of DNA

Question 9

What is Tm?

Answer 9

temperature at which a solution of DNA molecule is fifty percent melted

Question 10

In the right handed double helix where are the bases located and where is the backbone located?

Answer 10

bases = interior
backbone = exterior

Question 11

What is the right handed double helix stabilized by?

Answer 11

van der Waals and hydrophobic forces