Lecture 1

Question 1

Chargaff’s conclusion

Answer 1

1. 1st rule: [A=T] and [G=C]

2. 2nd rule: composition of DNA varies between species

Question 2

Griffith’s conclusion

Answer 2

a chemical substance/transforming principle is bearer of genetic information

Question 3

Avery’s conclusion

Answer 3

DNA is the chemical substance that causes transform

it is the genetic information

Question 4

x-ray diffraction pattern in photo 51

Answer 4

helical structure
double-stranded
bases perpendicular point to the centre

Question 5

who’s information did Watson and Crick use

Answer 5

Franklin’s photo 51

Chargaff’s 2nd rule

Question 6

direction of DNA synthesis

Answer 6

5’ to 3’ (phosphate and OH groups)

Question 7

nucleotide monomers joined together with

Answer 7

phosphodiester bonds

Question 8

how many H bonds between purines

Answer 8

cytosine guanine- 3

Question 9

how many H bonds between pyridamines

Answer 9

thymine adenine -2

Question 10

structure of DNA

Answer 10

double stranded helical structure
sugar phosphate backbone- outside, bases- inside
stabilised by H bonds
2 polynucleotide strands orientated opposite directions
two strands are anti-parallel