4.2 DNA Structure

Question 1

in what form does dna carry its sequence of deoxyribonucleotides?

Answer 1

through phosphodiester bonds

Question 2

how are the antiparallel polynucleotide strands stabilized to wind around each other?

Answer 2

through the following:
wan der walls (hydrogen bonds and stacking interactions )
ionic bonds through opposite strands

Question 3

what are the three distinct conformations that the dna double helix can have?

Answer 3

a dna
b dna
z dna (aka a-type, b-type, or z-type

Question 4

ester

Answer 4

carbonyl group bonded to an r group by using an oxygen that is placed in the middle

Question 5

thioester

Answer 5

carbonyl group bonded to an r group by using a sulfur

Question 6

phosphoester

Answer 6

phosphoryl group (p and o bond) bonded to an r group using an oxygen

Question 7

phosphodiester

Answer 7

phosphoryl group ( o and p bond) bonded to TWO r groups using oxygen bonds

Question 8

strand polarity

Answer 8

running from the 5 carbon end to the 3 carbon end

Question 9

how long is the diameter of the right hand double helix?

Answer 9

20 A

Question 10

minor grove of helix

Answer 10

12

Question 11

major of double helix

Answer 11

22

Question 12

pitch (rise/turn) of double helix

Answer 12

34

Question 13

what happens when transcription factors bind to the major groove?

Answer 13

therapeutic drugs can target the minor groove