baisics of DNA

Question 1

what was the evidence they used to prove for DNA

Answer 1

evidence from X-ray crystallography experiments

Question 2

what did crystallography suggest

Answer 2

two polynucleotide strands coiled in a right handed helix

Question 3

how are bases arranged

Answer 3

two chains running in opposite directions with complimentary base parings

Question 4

5 properties of DNA

Answer 4

1 - two polynucleotide strands coiled in a right handed helix

2 - strong covalent bonds between nucleotide

3 - polynucleotide strands are complementary - run in opposite directions

4- A T , G C

5 - base pairings held together by weak hydrogen bonds

Question 5

how many hydrogen bonds do Adenine and Thymine have

Answer 5

2

Question 6

how many hydrogen bonds do Cytosine and Guanine have

Answer 6

3

Question 7

how many polynucleotide strands are DNA made of

Answer 7

2

Question 8

whats the shape of DNA

Answer 8

double helix

Question 9

what is the pentose sugar in dna

Answer 9

deoxyribose

Question 10

what are the 2 types of bases called

Answer 10

purines

pyramidines

Question 11

what are the purine groups

Answer 11

adenine and guanine

Question 12

what are the pyrimidines bases

Answer 12

cytosine and thymine

Question 13

what is on the outside of the DNA molecule

Answer 13

deoxyribose sugar and phosphate group

Question 14

how are the 2 strands structure

Answer 14

facing each other pointing inwards

Question 15

what do the hydrogen bonds between the bases do

Answer 15

maintain the shape of the double helix

Question 16

what is the name to describe the nucleotide strands

Answer 16

antiparalel

Question 17

what are DNAs structural elements

Answer 17

• 2 polynucleotide strands in double helix
• pentose sugar is deoxyribose
  -deoxyribose and phosphate outside DNA
• bases two strands face each other
  -very long and thin
• nucleotides in one strand are in opposite direction in the complementary strand

Question 18

why is DNA suited to its function (4)

Answer 18

• very large mol
• very stable mol
• two strands able to seperate as held tog by hydrogen bonds
  -base pairs on inside of double helix