Central dogma & NA structure

Question 1

albinism

Answer 1

caused by recessive allele, causes defect in melanin synthesis: final step of converting Y –> melanin catalysed by tyrosinase (defect in tyrosinase causes albinism)

Question 2

Miescher

Answer 2

discovered nuclein, thought it was P store

Question 3

Phoebus Levene

Answer 3

found 4 ‘letters’ + thought it couldn’t be hereditary material as it wouldn’t allow for enough diversity

Question 4

Griffith - 1928

Answer 4

showed that Streptococcus pneumoniae can be transformed from rough to smooth

Question 5

Chargaff’s rules

Answer 5

A = T content, C = G content in cells

Question 6

Watson + Crick - 1952

Answer 6

suggested that X-ray diffraction data of Wilkins + Franklin was best explained by antiparallel double helix

Question 7

nucleotide

Answer 7

sugar + base + phosphate

Question 8

pentose sugar ring not planar

Answer 8

sugar puckering occurs - 2’ or 3’ C is out of plane (2’ endo or 3’endo conformation)

Question 9

purines - 2 rings

Answer 9

A + G

Question 10

pyrimidines - 1 ring

Answer 10

T + U + C

Question 11

Keto bases (C=O)

Answer 11

G + U + T

Question 12

Amino bases (C-NH2)

Answer 12

C + A

Question 13

nucleoside

Answer 13

sugar + base (NO phosphate)

Question 14

other roles of nucleotides

Answer 14

Can be used as intracellular signaling molecules (e.g. cAMP), intercellular neurotransmitters & high free energy of phosphoanhydride bond in ATP drives many biochemical reactions