Structure of DNA and RNA

Question 1

what type of bonds join nucleotides together

Answer 1

covalent bonds join phosphates to sugars in nucleotides and along the side backbone
hydrogen bonds join the bases together across the double stranded DNA

Question 2

how do DNA and RNA differ

Answer 2

number of strands (2 vs 1)
base composition (RNA had U instead of T)
type of pentose sugar (DNA has deoxyribose and RNA has ribose)

Question 3

what are nitrogenous bases

Answer 3

pyrimidines (smaller): cytosine/uracil/thymine

purines (larger): guanine/alanine

Question 4

how are DNA strands drawn

Answer 4

antiparallel (5 to 3 and 3 to 5)
complementary base pairing
hydrogen bonds drawn as dotted lines

Question 5

what is the function of a nucleosome

Answer 5

nucleosomes are only in eukaryotic cells
they have a core of 8 histones
DNA is wrapped around the nucleosomes (supercoiling)

Question 6

what did hershey and chase prove

Answer 6

DNA is the genetic material of viruses

Question 7

what did crick and watson create

Answer 7

created the 3D model of the double helix DNA

Question 8

what did rosalind franklin investigate

Answer 8

franklin studied DNA by X-Ray diffraction to calculate dimensions of the DNA helix
watson and crick stole her work to build their model and then won a Nobel Prize

Question 9

what is a nucleotide

Answer 9

building blocks of nucleic acids
contains pentose sugar (ribose/deoxyribose)
-phosphate group
nitrogenous base (A/T/G/C/U)
(adenine/thymine/guanine/cytosine/uracil)

Question 10

what is the importance of dna

Answer 10

codes for proteins which in turn control cell processes including the production of chemicals in specialised cells

• permanently stores information about which enzymes need to be made
• organises information so different cells can use the parts they need and ignore the rest
• contained within chromosomes (found in nucleus) but require rna to be used