dna structure and replication

Question 1

what does a nucleotide consist of

Answer 1

Nitrogenous base
Pentose sugar (5 carbon sugar)
Phosphate

Question 2

nitrogenous bases parent compounds

Answer 2

purine- adenine guanine

pyrimidine- cytosine uracil thymine

Question 3

how is. a nucleotide formed

Answer 3

nitrogenous base + pentose sugar + phosphate

condensation reaction, 2 water molecules

Question 4

how are dinucleotides formed

Answer 4

phosphodiester bond between 5’ phosphate group of one nucleotide and 3’ oH group of another nucleotide

formed by condensation reaction, 1 water molecule lost in process

Question 5

nucleotides become nucleic acids/ polynucleotides?

Answer 5

condensation reaction between phosphate group of one nucleotide & sugar group of another nucleotide

alternating sugar and phosphate molecules form a backbone with one of the bases attached to each of the sugar molecules along strand

since bases vary, represent unique sequence that carries coded info held by nucleic acid

Question 6

whats consistent base pairing?

Answer 6

adenine:thymine
1:1

guanine:cytosine
1:1

Question 7

what is dna?

Answer 7

consist of 2 polynucleotide strands paired together

held by hydrogen bonds between paired bases (C-G, A-T) - aka complementary base pairing

nucleotides contain deoxyribose

Question 8

draw a nucleotide

Question 9

how is dna arranged

Answer 9

2 strands arranged anti parallel

1 strand runs from 3’ OH to 5’ phosphate , the other from 5’ phosphate to 3’ OH

Question 10

how is DNA organised?

Answer 10

in nucleus of each cell, DNA is packaged into thread-like structures called chromosomes.